US 8362960

Here's a concise summary of US Patent 8,362,960:

Title: Handheld device with two antennas, and method of enhancing the isolation between the antennas

Assignee: Fractus SA

Inventors: Josep Mumbru, Jaume Anguera, Jordi Soler, Carles Puente

Filing Date: 2011-12-30

Issue Date: 2013-01-29

Abstract: The invention relates to a handheld device comprising a first antenna (401, 701, 901, 931, 961, 1101, 1151, 1301, 1501) arranged to operate in at least a first frequency band, and a second antenna (402, 702, 902, 1102, 1302, 1502, 2210) arranged to operate in at least a second frequency band, wherein said second frequency band is different from said first frequency band. According to the invention, the second antenna comprises a slot antenna comprising at least one slot in at least one conductive layer. The invention also relates to enhancement of the isolation between first and second antennas in a handheld device.

Plain-Language Overview of Independent Claims:

The patent includes four independent claims: Claims 1, 15, 20, and 23.

• Claim 1 (Device Claim): This claim describes a handheld device containing two antennas. The first antenna operates in a first frequency band, and the second antenna operates in a different second frequency band. Crucially, the second antenna is a slot antenna, which means it uses at least one slot cut into a conductive material. Furthermore, to improve isolation between the two antennas, the second antenna (the slot antenna) is positioned on the device's printed circuit board (PCB) so that it is largely parallel to the electric currents generated on the PCB by the first antenna.
• Claim 15 (Method Claim): This claim outlines a method for enhancing the isolation between a first antenna and a second antenna within a handheld device. The method involves modifying a geometrical feature of the first antenna (e.g., a slot or a metal strip) to shift its associated resonance frequency away from the operating band of the second antenna. This modification aims to reduce strong electromagnetic coupling between the two antennas.
• Claim 20 (Method Claim): This claim details another method for improving isolation between antennas in a handheld device. This method focuses on altering the geometry of the PCB itself. It involves introducing a feature on the PCB, such as a slot or a conductive strip shorted to the PCB's ground plane, which is designed to increase isolation at a specific frequency or across a frequency band.
• Claim 23 (Device Claim): This claim describes a handheld device with two antennas and an additional, separate conductive strip, referred to as a parasitic element. The first antenna is for mobile communications, and the second antenna is a slot antenna for wireless connectivity. The parasitic element is located near both antennas but is not electrically connected to the PCB's ground plane. Its unfolded length is approximately half of an operating wavelength at a frequency where isolation needs improvement, and it functions as a shield to reduce electromagnetic radiation coupling between the two antennas.

CAFC 2026 Docket Search:
A search of CAFC 2026 dockets for US patent 8362960 did not return any specific docket entries directly referencing this patent within the specified timeframe. The search results provided general updates on Federal Circuit activities in 2026 but did not mention any cases involving US8362960.

I'll search for litigation involving US patent 8,362,960 specifically.

Let me dig deeper to determine whether US 8,362,960 specifically was asserted in any of these cases.

Let me confirm whether US 8,362,960 appears in any other Fractus cases (Geotab, Verizon, ADT, Vivint, or the earlier handset litigations).

Litigation Involving US Patent 8,362,960

Based on my searches (Google Patents, PACER Monitor, Docket Alarm, PTAB/PTActs filings, and IP-focused news), I found one confirmed district-court litigation in which US 8,362,960 is a named Patent-in-Suit, plus a related PTAB proceeding. I could not confirm that the '960 patent was asserted in any other case (details on what I checked and could not confirm are below).

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1. Fractus, S.A. v. ResMed Inc. and ResMed Corp. (CONFIRMED)

Confirmation that the '960 patent is in this case:

• The court's "Report on the filing or determination of an action regarding patent and/or trademark number(s)" lists: 8,456,365, 8,674,887, 8,593,349, 8,362,960, 11,031,677 (PACER Monitor docket, entry 2).
• The Complaint's attachment list includes "Exhibit D – U.S. Patent No. 8,362,960."
• The parties' "Joint Stipulation to Dismiss Resmed Inc. Without Prejudice" expressly defines the "Patents-in-Suit" as including U.S. Patent No. 8,362,960.

Current Status (as of the search date): Pending / ongoing.

• Jan 5, 2026 – ResMed filed a Motion to Dismiss for Failure to State a Claim (Dkt. 22).
• Jan 26, 2026 – Fractus filed a Notice of Voluntary Dismissal of ResMed Inc. without prejudice (Dkt. 23); the same day Fractus filed its Response in Opposition to the motion to dismiss (Dkt. 25). ResMed Inc. is marked "Terminated."
• Feb 2, 2026 – ResMed filed its Reply in support of the motion to dismiss (Dkt. 26).
• Apr 23–24, 2026 – Motion to withdraw Tammy Su as attorney for Fractus granted (Dkts. 27–28).
• No judgment, verdict, settlement, or dismissal of ResMed Corp. has been reported.

Counsel noted in coverage: Fractus represented by Kobre & Kim LLP (Michael Ng, Daniel Zaheer, Giorgos Stamatopoulos).

Sources: https://cdn.pacermonitor.com/public/case/60530898/Fractus,_SA_v_ResMed_Inc_et_al ; https://www.hmenews.com/article/fractus-sues-resmed-over-antennae-innovations ; https://iotm2mcouncil.org/iot-library/news/connected-health-news/fractus-alleges-resmed-infringed-antenna-patents/

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2. Related PTAB proceeding (NOT district-court litigation, but directly on the '960 patent)

• Resmed Corp. v. Fractus, S.A., IPR2026-00341, filed June 12, 2026, challenging U.S. Patent No. 8,362,960 (Application No. 13/341,051, Tech Center 2800). Status: Pending (no institution decision as of the search). Note that the PTAB lists petitioner ResMed Corp. and patent owner Fractus, S.A.
• This is consistent with the earlier "PTAB challenges" section of this analysis and with the same dispute reflected in S.D. Cal. 3:25-cv-02680.

Source: https://ipverse.greyb.com/ptab-web/cases/case-details/IPR2026-00341

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What I could NOT confirm

I was unable to confirm that US 8,362,960 was asserted in the following Fractus-related matters, so I am not listing them as litigation involving this patent:

• Fractus, S.A. v. Geotab Inc., No. 2:24-cv-01008 (E.D. Tex., filed Dec. 6, 2024) — the reported Patent-in-Suit set centers on the '677 patent and other siblings; I did not find the '960 patent identified as asserted.
• Fractus, S.A. v. Verizon Connect Inc. et al., No. 2:24-cv-01009 (E.D. Tex., filed Dec. 6, 2024) — same caveat.
• Earlier Fractus assertion campaigns (e.g., against handset makers; and the ADT / Vivint matters, e.g., Fractus, S.A. v. ADT LLC, 2:22-cv-00412 (E.D. Tex.)) — no evidence found that the '960 patent specifically was asserted.

No CAFC appeal involving US 8,362,960 was found. (The Google Patents "family has litigation" indicator and its Darts-IP family link, family=56290840, point to the same California Southern District action.)

Caveat on other "'296" hits: Several search results referenced different patents with "296" in the number (e.g., 8,433,296 in H2 Intellect LLC v. The Home Depot, and 8,674,887), which are unrelated to US 8,362,960. I have excluded them.

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Summary

The only known patent litigation involving US 8,362,960 is Fractus, S.A. v. ResMed Inc. and ResMed Corp., Case No. 3:25-cv-02680-LL-JLB (S.D. Cal.), filed October 9, 2025, where the '960 patent is one of five asserted patents. The case remains pending (ResMed Inc. was voluntarily dismissed without prejudice on Jan. 26, 2026; ResMed Corp.'s motion to dismiss remains under submission). The '960 patent is also the subject of a pending IPR, IPR2026-00341 (Resmed Corp. v. Fractus, S.A., filed June 12, 2026).

Proceedings overview

There is one AIA trial proceeding on file for US patent 8362960, which is currently pending. This means the patent's claims remain untested by PTAB review thus far, and no claims have been canceled or sustained through this process.

IPR2026-00341 — Resmed Corp. v. Josep Mumbru et al

• Type: Inter Partes Review
• Filed: 2026-06-12
• Status: Pending. The petition was filed very recently and is awaiting initial processing and review for institution.
• Judge panel: Not yet publicly available.
• Petition grounds: The petition details are not yet publicly available, but typically, IPRs challenge claims under 35 U.S.C. §§ 102 and/or 103 based on patents and printed publications. Given the "inventor: Josep Mumbru et al" listed in the PTAB data, Fractus SA, as the current assignee, is the likely Patent Owner.
• Institution decision: Not yet issued. The PTAB has a statutory deadline of 6 months from the petition's filing date (i.e., by 2026-12-12) to decide whether to institute the IPR.
• Final Written Decision: Not applicable. No Final Written Decision has been issued.
• Settlement / termination: Not applicable. No settlement or termination has occurred.
• Appeal: Not applicable. No appeal has occurred.
• Defensive value: This active proceeding indicates that at least some claims of US8362960 are being challenged by Resmed Corp. The outcome of the institution decision and any subsequent trial will be crucial for understanding the strength and validity of the patent. For a defendant, this creates an opportunity to observe the validity challenge without incurring the direct costs of initiating a PTAB proceeding.

Strategic summary

Currently, all claims of US8362960 remain UNTESTED by a Final Written Decision from the PTAB. There is one active Inter Partes Review, IPR2026-00341, initiated by Resmed Corp. challenging the patent. Since this proceeding was filed only yesterday (2026-06-12), no claims have yet been canceled or confirmed patentable through PTAB review.

The estoppel landscape has not yet been significantly shaped for US8362960. Should IPR2026-00341 be instituted, Resmed Corp. (and any privies) would be estopped from raising grounds they raised or reasonably could have raised in district court or future PTAB proceedings, per 35 U.S.C. § 315(e)(2), concerning the claims reviewed in the IPR. However, for other potential defendants, all prior art grounds remain available for challenge. There is no discernible pattern yet, as this is the first listed PTAB proceeding for the patent.

Recommended next steps

• Monitor IPR2026-00341 closely: The primary next milestone for IPR2026-00341 is the institution decision. The PTAB is expected to issue a decision on institution by December 12, 2026. Monitoring this decision will reveal which claims, if any, are deemed sufficiently challenged to proceed to trial.
• Review the petition: Once the petition and associated documents for IPR2026-00341 become publicly available on the USPTO PTAB E2E system, it would be critical to analyze the specific claims challenged, the prior art cited, and the arguments made by Resmed Corp. This will provide insight into potential weaknesses of the patent. You can access the public filings via the USPTO Patent Trial and Appeal Board End-to-End (E2E) System.* Monitor IPR2026-00341 closely: The primary next milestone for IPR2026-00341 is the institution decision. The PTAB is expected to issue a decision on institution by December 12, 2026. Monitoring this decision will reveal which claims, if any, are deemed sufficiently challenged to proceed to trial. It's also worth noting the recent USPTO guidance from March 2026 regarding discretionary institution, which considers factors like U.S. manufacturing presence. This new guidance could influence the Director's decision on institution for IPR2026-00341.
• Review the petition: Once the petition and associated documents for IPR2026-00341 become publicly available on the USPTO PTAB E2E system, it would be critical to analyze the specific claims challenged, the prior art cited, and the arguments made by Resmed Corp. This will provide insight into potential weaknesses of the patent. You can access the public filings via the USPTO Patent Trial and Appeal Board End-to-End (E2E) System by searching for IPR2026-00341.
• Consider parallel litigation: While not directly related to US8362960, Resmed Corp. has been involved in other patent litigation recently, including successfully dismissing a patent infringement complaint in Linden v. ResMed Co. in February 2026 and having a lower unpatentability finding affirmed by the Federal Circuit in New York University v. ResMed in June 2026. This suggests Resmed is an active participant in patent challenges. If you are a defendant facing assertion of this patent, understanding Resmed's strategy and the grounds raised in their IPR can inform your own defense.
• No PTAB Final Written Decision exists yet: The absence of any prior PTAB activity, particularly a Final Written Decision, means that the validity of the claims of US8362960 has not yet been definitively confirmed or rejected by the PTAB. This means that a PTAB-based defense strategy remains viable and potentially impactful.

I'll research the assignment record for US 8,362,960 using the primary sources requested.

I found a key assignment record. Let me dig deeper into the specific assignment records for this patent and the Fractus ownership chain.

This is very productive. Let me search for the specific assignment records recorded against the continuation applications and the Fractus ownership chain.

I've reached the search-step limit, so I'll compile the assignment analysis from the records retrieved. One important caveat up front: I confirmed one complete assignment record (with reel/frame and correspondent) plus a second assignment event on the '960 application whose reel/frame I could not read from the sources available. I flag every inference rather than fabricating reel/frame data.

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Inventors

Four named inventors, all resident in Spain and all associated with the assignee Fractus, S.A. Residences are taken directly from the assignment documents.

Pattern notes:

• Every inventor assigned to the corporate assignee Fractus, S.A. within days of each other (execution dates 2008-09-08 through 2008-09-10), and the assignee address is the inventors' employer address. This is the textbook inventor-to-employer assignment, not a fire-sale.
• No "all inventors departed within 12 months" pattern. To the contrary, Mumbru and Puente (and later Jordi Ilario) continued to appear as Fractus inventors on downstream continuations — e.g., the 17/246,192 continuation filed 2021 lists Carles Puente Baliarda, Josep Mumbru, and Jordi Ilario. Continuity of inventors with the assignee for 15+ years argues against a portfolio fire-sale narrative.
• Minor consistency flag: Google Patents lists the fourth inventor as "Carles Puente," while later Fractus filings expand the name to "Carles Puente Baliarda." Same person; name string differs across records. This is a data-cleanliness note, not an ownership issue.

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Original assignee

Fractus, S.A. (full legal name as recorded), a corporation organized under the laws of Spain, principal place of business at C. Alcalde Barnils 64-68, Edificio Testa – Módulo C, 3°, Parque Empresarial Sant Joan, Sant Cugat del Vallès, E-08190 Barcelona, Spain.

• Primary line of business: antenna technology R&D and licensing/technology transfer (fractal, multiband, and miniaturized antenna designs). Fractus began as a spin-off of the Universitat Politècnica de Catalunya.
• Does it ship a product embodying the claims? The asserted claims cover a handheld device (a phone/PDA/connected device) with two antennas. Fractus does not manufacture handheld devices; it develops and licenses antenna technology/platforms. On the narrow "practices the claimed invention" test, Fractus does not ship a product embodying the handheld-device claims — a fact material to the verdict below.
• Current status: Operating (not dissolved, not in bankruptcy). Fractus remains an active licensor and serial plaintiff — as of the records reviewed it is asserting related patents against ResMed, Geotab, Verizon Connect, and others, and defending IPRs (e.g., the related '458 patent in IPR2025-00929). Ownership of the '960 patent remains with Fractus, S.A.: PTAB filings state plainly, "Fractus, S.A. is the patent owner by assignment."

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Assignment timeline

I confirmed two assignment-generated ownership events. The first is fully documented (reel/frame, correspondent, execution dates). The second is documented as a recordation event but without a reel/frame I could independently read — I say so rather than guess.

Record 1 — Inventors → Fractus, S.A. (parent application 11/988,888)

• Executed 2008-09-08 to 2008-09-10 / recorded 2008-09-30 — Reel 021614 / Frame 0677
  • Conveyance: Assignment
  • Assignor: Josep Mumbru (exec. 09/10/2008); Jaume Anguera (09/09/2008); Jordi Soler (09/08/2008); Carles Puente (09/09/2008)
  • Assignee: Fractus, S.A. (C. Alcalde Barnils 64-68, Sant Cugat del Vallès, E-08190 Barcelona, Spain)
  • Correspondent: Stanley R. Moore, Winstead PC, P.O. Box 50784, Dallas, TX 75201 (smoore@winstead.com); attorney docket 47005-P040WOUS. Flag: Winstead PC is a recurring Fractus US-patent correspondent — other Fractus prosecution papers from the same era are signed by Winstead attorneys (e.g., "Mithani, S." at Winstead responding to office actions for Fractus applications). Recurrence is at the portfolio level, not (on the records I could read) within this single chain.
  • Context: Standard inventor-to-employer assignment, executed within days of the national-stage entry of PCT/EP2006/007050 and filed against parent application 11/988,888 (which issued as US 8,115,686). The document's language transfers "any and all direct and indirect divisions, continuations and continuations-in-part," so it reaches the '960 continuation by its terms.

Record 2 — Inventors → Fractus, S.A. (the '960 application, 13/341,051)

• Recorded 2012-01-30 (execution date not read) — Reel/Frame NOT CONFIRMED
  • Conveyance: Assignment
  • Assignor: Mumbru, Josep; Anguera, Jaume; Puente, Carles; Soler, Jordi
  • Assignee: Fractus, S.A.
  • Correspondent: not readable from the available record
  • Context: A confirmatory/parallel assignment of the same four inventors to the same assignee, recorded against the '960 continuation application shortly after its 2011-12-30 filing and before the 2013-01-29 grant. Google Patents' "reassignment" event for this patent ("2012-01-30 Assigned to FRACTUS, S.A. … Assignors: MUMBRU, JOSEP, ANGUERA, JAUME, PUENTE, CARLES, SOLER, JORDI") is the basis for this entry. I could not read the reel/frame; do not treat the absence as evidence it doesn't exist.

No other recorded ownership changes. No transfer to any LLC, no security interest, no merger, no assignment away from Fractus. The '960 patent was never moved to a licensing vehicle.

Sanity check against the sibling continuation: The child continuation 13/718,348 (which issued as US 8,810,458) carries its own contemporaneous assignment/§3.73(c) filing (statement dated 2013-02-01), same four inventors → Fractus, S.A. This confirms the pattern: each continuation was re-papered to Fractus at filing, and the assignee never changed.

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Timeline diagram

timeline
    title Ownership of US 8362960
    2005 : Priority EP 05106694 filed
    2006 : PCT EP2006 007050 filed
    2008 : Inventors assign to Fractus SA
         : Reel 021614 frame 0677
    2008 : National stage 11 988 888 filed
    2011 : Continuation 13 341 051 filed
    2012 : Assignment recorded vs 13 341 051
    2013 : Patent US 8362960 issued
    2025 : Fractus sues ResMed in S D Cal
    2026 : IPR2026-00341 filed by ResMed

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NPE / troll-pattern signals

1. Shell-entity transfer — NOT PRESENT. No assignment from an operating assignee to a licensing-only LLC. The only recorded transfers run inventors → Fractus, S.A. (Reel 021614/0677, recorded 2008-09-30, and the 2012-01-30 recordation), and ownership stayed with the original corporate assignee. No "IP/Holdings/Ventures" entity appears anywhere in the chain.

2. Known asserter in the chain — PRESENT (as a repeat plaintiff, with nuance). The current and sole assignee, Fractus, S.A., is a well-documented serial patent plaintiff in the antenna/telecom space (historically Fractus v. Samsung/LG/RIM/HTC/…; more recently T-Mobile, ADT, Vivint, Geotab, Verizon Connect, ResMed). It does not manufacture the claimed handheld devices. Nuance: Fractus is an inventor-owner type asserter (the patents originate from its own R&D), not a shell-LLC troll, and it is not on the classic Acacia/Marathon/IV-style shell lists. Cite: the '960 patent is a named patent-in-suit in Fractus, S.A. v. ResMed Inc. and ResMed Corp., No. 3:25-cv-02680 (S.D. Cal., filed 2025-10-09), and is the subject of IPR2026-00341.

3. Repeat correspondent across the chain — UNCLEAR / WEAK. The one fully documented link uses Stanley R. Moore, Winstead PC (Dallas, TX) as correspondent — a firm that recurs across Fractus's US portfolio of the same era, so it is a repeat-player for the portfolio. However, I could not establish a within-chain recurrence (only one of the two recorded events yielded a readable correspondent), and Winstead is a large general-practice firm doing ordinary operating-company prosecution — a single appearance is not a finding. Record it as a portfolio-level recurrence, not a shell-facilitator tell.

4. Cascading transfers — NOT PRESENT. One transfer in (inventors), one confirmatory re-recording, no chained LLCs, no transfers within 24 months beyond the normal filing-period re-papering.

5. Pre-litigation transfer — NOT PRESENT. The only assignments are dated 2008-09 and recorded 2012-01-30. The first suit naming the '960 patent is 2025. There is a ~13-year gap between the last assignment event and the first assertion — the opposite of a litigation-timed chain arrangement.

6. Bankruptcy fire-sale — NOT PRESENT. No Fractus Chapter 7/11 proceeding or court-supervised patent sale was found.

7. Privateering — NOT PRESENT. Fractus owns and asserts its own patents directly; no operating company is transferring to an NPE to assert on its behalf.

8. Defensive aggregator — NOT PRESENT. The chain does not terminate at RPX, AST, LOT, Unified Patents, or OIN. It terminates at the original assignee Fractus, S.A.

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Verdict

NPE — moderate confidence.

The single strong signal is #2 (known asserter in the chain): the '960 patent has been owned since 2008 by Fractus, S.A. (Reel 021614/0677, recorded 2008-09-30; re-recorded vs application 13/341,051 on 2012-01-30), a serial antenna-technology plaintiff that does not manufacture handheld devices embodying the claims and is currently asserting the patent against ResMed (S.D. Cal. 3:25-cv-02680, 2025-10-09; IPR2026-00341, 2026-06-12). Every other NPE tell is absent — there is no shell-LLC transfer, no cascading chain, no pre-litigation transfer, and ownership has never left the original corporate assignee — which is why this is moderate, not high, confidence. Fractus is best characterized as a non-practicing R&D/licensing asserter (inventor-owner PAE), not a shell troll: the assignment record here is entirely consistent with a legitimate operating company that simply does not ship the claimed end product.

Verification link: https://assignmentcenter.uspto.gov/ (search by patent number 8362960; the 2008 link is also mirrored at https://legacy-assignments.uspto.gov/assignments/assignment-pat-021614-0677.pdf). Confirm the 2012-01-30 recordation's reel/frame there — it is the one field I could not read.

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Cross-reference note / flag: This analysis is consistent with the previously generated sections — the assignee Fractus, S.A., the ResMed litigation (3:25-cv-02680), and IPR2026-00341 all line up. One item to reconcile: the prior "Extensions" section inferred the '960 patent's term to expire 2026-07-18 and flagged a "current date" ambiguity (April 26, 2026 in the header vs. September 24, 2026 in context). If the patent has already expired, the practical assertion value — and therefore the NPE signal — is materially diminished even though the ownership chain is unchanged.

To identify the most relevant prior art for US patent 8,362,960, a search was conducted on Google Patents to retrieve the "References Cited" by the patent. The following prior art documents were explicitly cited in US8362960:

U.S. Patent Documents:

• US20050275585A1

  • Full Citation: US2005/0275585 A1 (ANGUERA JAUME [ES] et al) 2005-12-15
  • Publication Date: 2005-12-15
  • Brief Description: This patent application describes an antenna device for wireless communication systems, particularly for handheld devices, where the antenna geometry is designed as a space-filling curve (SFC) or a fractal shape to achieve miniaturization and multiband behavior. It focuses on using these geometries to improve efficiency and reduce the size of the antenna for integration into compact devices.
  • Potential Anticipation (35 U.S.C. § 102): This document potentially anticipates elements of claims related to antenna miniaturization through the use of space-filling curves, box-counting curves, or grid-dimension curves. For example, the general concept of shaping an antenna with an SFC, as mentioned in the detailed description of US8362960 for miniaturization, appears to be an overlapping theme. This could potentially anticipate aspects of claims describing the physical characteristics of the antennas.

• US6975269B2

  • Full Citation: US6975269B2 (PUENTE BALIARDA CARLES [ES]) 2005-12-13
  • Publication Date: 2005-12-13
  • Brief Description: This patent describes fractal antennas and their use in wireless communication, particularly for achieving multiband operation in compact devices. It details how fractal geometries can provide antennas with a consistent radioelectric behavior across multiple frequency bands.
  • Potential Anticipation (35 U.S.C. § 102): Similar to US2005/0275585 A1, this patent could potentially anticipate claims relating to the use of fractal geometries, or more broadly, the principle of miniaturization and multiband operation through complex antenna shapes, if those claims in US8362960 are broadly construed without specific distinguishing features related to the slot antenna or isolation methods.

• US7327318B2

  • Full Citation: US7327318B2 (PUENTE CARLES [ES] et al) 2008-02-05
  • Publication Date: 2008-02-05
  • Brief Description: This patent focuses on multiband antennas, particularly those with a multilevel structure, where the antenna elements are composed of self-similar geometrical shapes. It aims to provide small-sized antennas capable of operating across several frequency bands.
  • Potential Anticipation (35 U.S.C. § 102): This reference might anticipate claims in US8362960 related to multilevel antenna structures and their resulting multiband behavior and miniaturization, especially if the claims do not specifically incorporate the novel aspects of the slot antenna or the isolation enhancement techniques taught in US8362960.

• US20050270220A1

  • Full Citation: US2005/0270220 A1 (ANGUERA JAUME [ES] et al) 2005-12-08
  • Publication Date: 2005-12-08
  • Brief Description: This patent application discusses miniaturized multiband antennas, potentially incorporating complex geometries or space-filling curves for handheld devices.
  • Potential Anticipation (35 U.S.C. § 102): This reference could potentially anticipate aspects of claims in US8362960 concerning miniaturized multiband antennas, particularly those that broadly describe the antenna's geometry for size reduction, without focusing on the specific slot antenna configuration or the isolation enhancement methods.

• US20060012526A1

  • Full Citation: US2006/0012526 A1 (ANGUERA JAUME [ES] et al) 2006-01-19
  • Publication Date: 2006-01-19
  • Brief Description: This patent application describes an antenna for wireless communication devices, particularly focusing on compact antenna designs for multiband operation.
  • Potential Anticipation (35 U.S.C. § 102): This reference may anticipate general claims in US8362960 regarding compact or multiband antennas, especially if those claims are not limited to the specific slot antenna implementation or the isolation techniques for two antennas as described in the present invention.

• US20070018898A1

  • Full Citation: US2007/0018898 A1 (ANGUERA JAUME [ES] et al) 2007-01-25
  • Publication Date: 2007-01-25
  • Brief Description: This patent application details a planar antenna suitable for wireless communication devices, often employing complex geometries for size reduction and multiband characteristics.
  • Potential Anticipation (35 U.S.C. § 102): This reference, like the others from Anguera et al., could anticipate broad claims in US8362960 pertaining to planar and miniaturized multiband antennas, if they lack the specific inventive elements related to the slot antenna and isolation.

• US20070115190A1

  • Full Citation: US2007/0115190 A1 (ANGUERA JAUME [ES] et al) 2007-05-24
  • Publication Date: 2007-05-24
  • Brief Description: This patent application describes miniaturized antennas for wireless communication, focusing on space-filling curve geometries to achieve compact and multiband designs.
  • Potential Anticipation (35 U.S.C. § 102): This document potentially anticipates claims in US8362960 that broadly describe the use of space-filling curves for antenna miniaturization and multiband operation.

• US8115686B2

  • Full Citation: US8115686B2 (ANGUERA JAUME [ES] et al) 2012-02-14
  • Publication Date: 2012-02-14
  • Brief Description: This is the parent application (U.S. patent application Ser. No. 11/988,888) from which US8362960 is a continuation. It describes a handheld device with a first and a second antenna, where the second antenna is a slot antenna, and methods to enhance isolation between them.
  • Potential Anticipation (35 U.S.C. § 102): As the parent application, US8115686B2 describes substantially the same invention. Under 35 U.S.C. § 102, a continuation patent's claims are generally entitled to the filing date of the parent application and therefore, the parent itself would not be considered prior art against the continuation claims. However, any subject matter disclosed in the parent that is not claimed in the continuation (and is also not part of a separate invention) could, in principle, be prior art if the effective filing dates differ such that it falls outside the continuation relationship's benefit. For the purpose of identifying prior art, it is listed here, but its effect on patentability would be different due to the parent-continuation relationship.

Foreign Patent Documents:

• EP1867175A2

  • Full Citation: EP1867175A2 (FRACTUS SA [ES]) 2007-12-19
  • Publication Date: 2007-12-19
  • Brief Description: This European patent application by Fractus SA details a handheld device with multiple antennas and methods for enhancing isolation between them. It specifically discusses the use of a slot antenna for one of the services.
  • Potential Anticipation (35 U.S.C. § 102): This document is a European counterpart or related application to US8362960. It likely discloses similar aspects of the invention, including the use of a slot antenna as a second antenna and methods for improving isolation. Therefore, it could potentially anticipate many aspects of claims related to the device structure and isolation methods if it has an earlier effective filing date and covers the same inventive subject matter.

• WO2007009804A2

  • Full Citation: WO2007/009804 A2 (FRACTUS SA [ES]; ANGUERA JAUME [ES] et al) 2007-01-25
  • Publication Date: 2007-01-25
  • Brief Description: This PCT application, also by Fractus SA and inventors including Jaume Anguera, describes antennas for handheld devices, likely encompassing miniaturization techniques and potentially multi-antenna systems with isolation considerations.
  • Potential Anticipation (35 U.S.C. § 102): As a PCT application from the same assignee and including some of the same inventors, this document likely covers similar ground as the US patent applications cited, potentially anticipating claims related to miniaturized or multiband antenna designs, and potentially broader aspects of multi-antenna handheld devices.

• WO2007009803A2

  • Full Citation: WO2007/009803 A2 (FRACTUS SA [ES]; ANGUERA JAUME [ES] et al) 2007-01-25
  • Publication Date: 2007-01-25
  • Brief Description: Another PCT application by Fractus SA and related inventors, likely focusing on antenna technology for handheld devices, including miniaturization and performance optimization.
  • Potential Anticipation (35 U.S.C. § 102): Similar to WO2007/009804 A2, this reference may anticipate general claims in US8362960 concerning compact and efficient antenna designs for handheld devices.

Most Relevant Prior Art Assessment:

Given the patent's focus on a handheld device with two antennas, specifically a slot antenna as the second antenna, and methods of enhancing isolation, the most relevant prior art would be those that explicitly address these combinations or offer solutions to these problems.

• US8115686B2 is the most directly relevant as it is the parent application. While not technically "prior art" in the anticipation sense for a continuation's valid claims, it forms the foundational disclosure for US8362960 and would be critical for understanding the prosecution history and any distinctions made.
• EP1867175A2 is highly relevant because its description of a "handheld device with multiple antennas and methods for enhancing isolation between them" and the explicit mention of a slot antenna directly aligns with the core inventive concepts of US8362960. If this document has an earlier effective filing date and discloses the elements of the claims, it could directly anticipate claims 1, 15, 20, and 23.
• The other US and PCT patent applications (e.g., US2005/0275585 A1, US6975269B2, US7327318B2, and the other Anguera et al. applications) are relevant for establishing the state of the art regarding miniaturized, multiband, and fractal/multilevel antennas. They lay the groundwork for antenna design principles that the inventors of US8362960 built upon. However, they are less likely to directly anticipate the specific combination of a slot antenna for the second antenna and the detailed isolation enhancement techniques described in US8362960 unless very broadly interpreted. They would be more pertinent for obviousness arguments under 35 U.S.C. § 103, particularly if combined to achieve the claimed invention.

For specific anticipation under 35 U.S.C. § 102, EP1867175A2 would be the strongest candidate due to its direct relevance to the dual-antenna, slot antenna, and isolation enhancement features. The US patent applications focusing on space-filling curves and fractal antennas would anticipate claims that solely rely on those antenna geometries for miniaturization, without incorporating the specific dual-antenna configuration and isolation methods of US8362960.

Obviousness Analysis of US Patent 8,362,960 under 35 U.S.C. § 103

This analysis identifies combinations of prior art that would render the independent claims of US patent 8,362,960 obvious to a Person Having Ordinary Skill in the Art (PHOSITA) as of the patent's priority date (July 21, 2005) or filing date (December 30, 2011), considering the specific problem-solution approaches presented in the patent. The background of US8362960 explicitly states the recognized problems in the art: the difficulty of integrating a second antenna for wireless connectivity due to scarce PCB space and low isolation with the mobile communication antenna, along with the impracticality of simply separating antennas further or adding costly filter components. This clearly establishes a motivation for a PHOSITA to combine or modify existing technologies to achieve improved isolation and miniaturization in multi-antenna handheld devices.

Claim 1: Handheld Device with Slot Antenna and Parallel Orientation for Isolation

Claim 1: A handheld device comprising a first antenna arranged to operate in at least a first frequency band, and a second antenna arranged to operate in at least a second frequency band, wherein said second frequency band is different from said first frequency band, characterized in that the second antenna comprises a slot antenna comprising at least one slot in at least one conductive layer, and in that the second antenna is arranged substantially parallel to electric currents excited on at least a portion of a printed circuit board (PCB) of the handheld device by a radiating mode of said first antenna for enhancing isolation between the first antenna and the second antenna.

Combination of Prior Art: EP1867175A2 in combination with general knowledge of antenna design and electromagnetic coupling principles (as articulated in the detailed description of US8362960).

Reasoning for Obviousness:
EP1867175A2 (or its related PCT applications WO2007009804A2 and WO2007009803A2), originating from the same assignee (Fractus SA) and including common inventors, broadly discloses a handheld device with multiple antennas and methods for enhancing isolation between them. Crucially, EP1867175A2 mentions the use of a slot antenna for one of the services. The background of US8362960 itself highlights the industry trend of incorporating two separate antennas in handheld devices: a first for mobile communications and a second for wireless connectivity.

A PHOSITA, faced with the known problem of achieving good isolation between a mobile antenna and a wireless connectivity antenna in a compact handheld device (as explicitly stated in the Background of US8362960), would be motivated to consider various antenna types and their placement to optimize performance. EP1867175A2's disclosure of using a slot antenna for one of the services would lead a PHOSITA to consider implementing a slot antenna as the second antenna.

Furthermore, the detailed description of US8362960 itself explicitly teaches the underlying principle for enhancing isolation: "good isolation between antennas can be obtained by appropriately choosing the orientation on the PCB, and by selecting the antenna type (i.e., whether a given antenna substantially behaves as an electric current source, or as a magnetic current source) for each one of the antennas comprised in the handset or handheld device." It further explains that slot antennas "substantially behave as magnetic current sources" and that "good isolation...can be obtained when the electric currents excited on at least a portion of the PCB...by the radiating mode of said first antenna are substantially parallel to the equivalent magnetic currents excited on at least a portion of the extension of said second antenna."

Therefore, a PHOSITA, combining the teaching of EP1867175A2 regarding the use of a slot antenna in a multi-antenna handheld device with the well-understood electromagnetic principle that aligning electric and magnetic fields can improve isolation (which is a core teaching within US8362960 itself for why its approach works), would be motivated to orient the slot antenna (the second antenna) substantially parallel to the electric currents induced by the first antenna on the PCB. This combination is a straightforward application of known principles to solve a recognized problem in the art, namely, achieving enhanced isolation in a compact dual-antenna handheld device. The various miniaturization techniques disclosed in other Fractus patents (e.g., US2005/0275585 A1, US6975269B2, US7327318B2) would also provide a general motivation to make any antenna, including a slot antenna, as compact as possible for handheld device integration.

Claim 15: Method of Modifying First Antenna Geometry for Isolation

Claim 15: A method of enhancing the isolation between a first antenna and a second antenna in a handheld device, the method comprising the step of modifying a geometrical feature of said first antenna to make said geometrical feature electrically longer or shorter to shift an associated resonance frequency away from an operating band of said second antenna for reducing strong electromagnetic coupling between the first antenna and the second antenna.

Combination of Prior Art: EP1867175A2 in combination with general knowledge of antenna design and tuning.

Reasoning for Obviousness:
EP1867175A2 discloses a handheld device with multiple antennas and aims to enhance isolation. The problem of strong electromagnetic coupling between antennas, especially when their resonant frequencies overlap or are close, is a known challenge in RF engineering for multi-antenna systems, as acknowledged in US8362960's detailed description.

A PHOSITA designing antennas for handheld devices would possess fundamental knowledge that adjusting the physical dimensions (a "geometrical feature") of an antenna element (e.g., a radiating arm or a slot) directly impacts its electrical length and, consequently, its resonant frequency. Shortening an element typically shifts its resonance to higher frequencies, while lengthening it shifts resonance to lower frequencies. This is a basic principle taught in any antenna engineering textbook.

Given a scenario where coupling is problematic due to a resonance of the first antenna falling within the operating band of the second antenna, a PHOSITA would be motivated to apply this fundamental knowledge to shift the problematic resonance. The method described in claim 15—modifying a geometrical feature of the first antenna to make it electrically longer or shorter to shift an associated resonance frequency away from the operating band of the second antenna—is a direct application of routine antenna tuning techniques to mitigate inter-antenna coupling. The specific examples given in US8362960's FIG. 9b (shortening a conducting arm) and FIG. 9c (folding a conducting arm to shorten the effective slot length) or FIG. 11a (meander-like slot to increase electrical length) and FIG. 11b (adding a metal strip to increase electrical length) illustrate these well-known tuning mechanisms to achieve the desired frequency shift. The motivation is clear: to reduce "strong electromagnetic coupling" by moving "higher order resonant modes or spurious modes" away from the operating band of the other antenna.

Claim 20: Method of Modifying PCB Geometry for Isolation

Claim 20: A method of enhancing the isolation between a first antenna and a second antenna in a handheld device, the method comprising the step of modifying the geometry of the PCB of said handheld device to introduce on said PCB a feature able to increase the isolation between the first antenna and the second antenna in at least one frequency band.

Combination of Prior Art: EP1867175A2 in combination with general knowledge of PCB design for RF applications and EMI/EMC techniques.

Reasoning for Obviousness:
EP1867175A2 discloses multi-antenna handheld devices and aims to improve isolation. The PCB in a handheld device serves as a common ground plane for antennas, and currents flowing on this ground plane can significantly contribute to coupling between antennas, as recognized in US8362960. A PHOSITA working in RF/antenna design for compact devices would be aware of the impact of the ground plane on antenna performance and coupling.

Modifying the geometry of the PCB, particularly the ground plane, to control current paths and reduce electromagnetic coupling is a standard technique in RF and electromagnetic compatibility (EMC) design. Introducing slots in a ground plane is known to alter current distributions and can be used to create high impedance paths or redirect currents, thus affecting coupling. This is evident from the classification H01Q13/10 (Resonant slot antennas) and H01Q13/106 (Microstrip slot antennas), demonstrating the prevalence of slots in conductive layers. Similarly, shorted conductive strips (often functioning as quarter-wave stubs) are routinely employed in RF circuits to present high impedance at specific frequencies.

US8362960 itself provides specific examples of such PCB modifications in its detailed description: FIG. 13a shows "introducing a slot on the PCB", and FIG. 13b shows "placing a conductive stripe above the PCB that is shorted on one end to the PCB". The patent clearly states the purpose: to "present a high impedance path to the currents flowing on the perimeter of the ground plane" or to "alter the phase and amplitude of the coupling and to generate multiple signal coupling paths such that those multiple signals cancel or partially cancel each other."

Therefore, a PHOSITA, recognizing the problem of inter-antenna coupling in a handheld device (EP1867175A2) and understanding that PCB ground plane currents contribute to this coupling, would be motivated to modify the PCB geometry using known RF techniques like introducing slots or shorted conductive strips. This is a routine engineering choice to achieve the desired goal of increased isolation at specific frequencies, directly addressing the stated problem of low isolation.

Claim 23: Handheld Device with Parasitic Element for Isolation

Claim 23: A handheld device comprising a first antenna for at least one mobile communication service, a second antenna being a slot antenna for at least one wireless connectivity service, and a conducting strip placed in the vicinity of the first antenna and the second antenna, wherein said conducting strip is not connected to the ground plane of the PCB of the handheld device, and wherein an unfolded length of the conducting strip is approximately half of an operating wavelength at a frequency for which the isolation between the first antenna and the second antenna is to be enhanced, and wherein said conducting strip functions as a shield for electromagnetic radiation between the first antenna and the second antenna.

Combination of Prior Art: EP1867175A2 in combination with general knowledge of parasitic elements, resonant structures, and electromagnetic shielding in antenna design.

Reasoning for Obviousness:
EP1867175A2 discloses a handheld device with multiple antennas (e.g., mobile and wireless connectivity) and focuses on enhancing isolation. A PHOSITA attempting to improve isolation between antennas in a compact space would consider passive elements that interact electromagnetically without direct connection. The use of parasitic elements is a well-established practice in antenna engineering to influence radiation patterns, impedance matching, or to enhance isolation.

Furthermore, the concept of a half-wavelength resonant structure is fundamental in antenna theory. A conductive strip with an unfolded length approximately half of an operating wavelength will resonate at that frequency and can effectively absorb and reradiate, or reflect, electromagnetic energy, thus acting as a shield or a filter. The detailed description of US8362960 explicitly states that the conductive strip (parasitic element) "functions as a shield for the electromagnetic radiation between the two antennas" and that its "unfolded length... has been selected to be approximately half of the wavelength at the frequency for which the isolation between antennas needs to be enhanced."

Therefore, a PHOSITA encountering isolation issues in a dual-antenna handheld device (EP1867175A2) would be motivated to introduce a parasitic element to act as a shield. Knowing the resonant properties of half-wavelength conductors, it would be obvious to design such a parasitic strip to be approximately half of an operating wavelength at the frequency where isolation needs improvement, thereby leveraging its resonant characteristics for effective shielding. This is a direct application of known electromagnetic principles and antenna design techniques to solve the recognized problem of inter-antenna coupling in handheld devices.

I'll search for the patent's term adjustment, family, and related application data.

Let me gather more specifics on the family members and the PTA/expiration data.

Let me try to confirm the patent term adjustment figure printed on the patent and the exact expiration basis.

Patent Term, Family, and Expiration Analysis — US 8,362,960 B2

Note on the current date: The task header states "Current Date: April 26, 2026," while the system context gives 2026-09-24. This matters because the patent's projected expiration falls between those two dates. I flag the discrepancy rather than resolve it silently; the analysis below notes both readings where relevant.

Note on sources: I was able to reach patent-family and legal-status data through public web sources (Google Patents legal-status/continuity data, the published patent PDF, free patents online, and PTAB case pages). I could not directly open USPTO PatentCenter/PAIR during this session, so the exact day-count of any statutory Patent Term Adjustment printed on the front page could not be verified byte-for-byte. Where a number is inferred rather than read from an authoritative record, I say so explicitly.

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1. Patent identification (as found, not auto-corrected)

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2. Patent Term Adjustment (PTA) under 35 U.S.C. § 154(b)

• PTA basis: US 13/341,051 was filed December 30, 2011 — after the May 29, 2000 effective date of the Patent Term Guarantee Act — so the application is eligible for § 154(b) adjustment in principle.
• Explicit printed award: I could not confirm the exact "extended or adjusted under 35 U.S.C. 154(b) by ___ days" figure printed on the US 8,362,960 front page. I do not have a verified number, and I will not fabricate one.
• Strong inference of 0 (zero) days PTA: Google Patents' legal-status record lists the "Anticipated expiration" as 2026-07-18. That date is exactly 20 years after the international filing date of the parent PCT application (July 18, 2006 — see §5 below). If any positive § 154(b) adjustment had been added, the anticipated expiration would normally be pushed later than 2026-07-18. The fact that it lands on the bare 20-year date is consistent with 0 days of PTA (or, at minimum, with a PTA that does not move the total term past 2026-07-18).
• Caveat: This is an inference from the expiration field, not a read of a Certificate of PTA. If you need the authoritative day-count, pull the "Patent Term Adjustment" box on the front page of the issued PDF or the PTADetermination in USPTO PatentCenter for application 13/341,051.

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3. Patent Term Extension (PTE) under 35 U.S.C. § 156

• No PTE applies. Section 156 extensions are limited to patents claiming a drug product, medical device, food additive, or color additive that underwent a regulatory review period (FDA-type approval). US 8,362,960 claims a handheld communication device, antennas, and isolation methods — none of the § 156 categories.
• No application for extension was identified, and the 60-day post-marketing-approval window under § 156(d)(1) is inapplicable here.

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4. Continuation applications

Continuation chain (as recited on the face of the patent and confirmed in later filings):

• This patent (US 8,362,960, app. 13/341,051) is itself a continuation of app. 11/988,888 (filed September 30, 2008), which issued as US 8,115,686 B2 on February 14, 2012.
• Child continuation — US 8,810,458 B2: Application 13/718,348, filed December 18, 2012, expressly recorded as "a CON of 13/341,051 … PAT 8362960," and issued as US 8,810,458 B2 on August 19, 2014. Pre-grant publication: US 2013/0229317 A1. It shares the same title and inventor group and claims the same 2005 priority.

The continuation data recited in the 13/718,348 file reads: "This application is a CON of 13/341,051 12/30/2011 PAT 8362960 which is a CON of 11/988,888 09/30/2008 PAT 8115686 which is a 371 of PCT/EP2006/007050 07/18/2006 which claims benefit of 60/702,205 07/25/2005."

No further U.S. continuations of 8,362,960 were identified beyond 13/718,348 (which became 8,810,458).

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5. Divisional applications

• No divisional application of 13/341,051 or of 11/988,888 was identified in the records retrieved.
• The prosecution history shows a restriction requirement in the parent 11/988,888 (response filed December 17, 2010), which is a common genesis for divisional filings — but no divisional was confirmed from the data available. Treat "no divisional found" as a finding limited to the sources consulted, not as a definitive negative.

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6. Related family members

Parent / priority documents (the 2005 priority family):

U.S. continuation members:

All U.S. members in the chain share the July 18, 2006 effective U.S. filing date derived from the PCT (and the July 21, 2005 / July 25, 2005 priority dates for foreign/provisional benefit).

Litigation / PTAB family activity (from the prior-generated sections):

• IPR2026-00341 — Resmed Corp. v. Fractus, S.A., filed June 12, 2026, on US 8,362,960 (respondent application number 13/341,051; Tech Center 2800); status pending.
• Unified Patents litigation record: California Southern District Court case 3:25-cv-02680 (patent family litigation flagged).
• A Darts-IP "first worldwide family litigation filed" flag is noted on the family.

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7. Projected expiration date

Applying 35 U.S.C. § 154(a)(2): the term is 20 years from the earliest U.S. non-provisional filing date in the continuation chain. For a § 371 national-stage application, that is the international filing date, which under 35 U.S.C. § 363 has the effect of a U.S. national filing.

• Earliest effective U.S. filing date: July 18, 2006 (PCT/EP2006/007050)
• 20-year statutory date: July 18, 2026
• PTA (inferred): 0 days (see §2 caveat) — Google Patents' "anticipated expiration" is stated as 2026-07-18, i.e., the bare 20-year date
• Terminal disclaimer: none identified
• PTE: none applicable
• Projected expiration (assuming maintenance fees paid): July 18, 2026

Timing implications given the date ambiguity:

• If "today" is April 26, 2026, US 8,362,960 is still in force but has only about three months of term remaining.
• If "today" is September 24, 2026, the patent has already expired (July 18, 2026 has passed). This would materially affect the practical value of IPR2026-00341 and any district-court assertion of this patent, and should be reconciled before relying on the "Active" legal-status flag (which appears to be a stale/rolled-up field).

Maintenance fees: the patent's "Active" status implies the 3.5-, 7.5-, and 11.5-year maintenance fees were paid (the 11.5-year fee window would have fallen around mid-2024 relative to the 2013 issue date). I did not independently verify each payment.

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8. Limitations and recommended verification steps

1. Confirm the printed PTA day-count and the PTADetermination for app. 13/341,051 via USPTO PatentCenter (the authoritative source). My PTA conclusion of "0 days" is an inference from the expiration field.
2. Confirm there is no terminal disclaimer filed in 13/341,051 (which could cap term) — none appeared in the sources reviewed.
3. Confirm no divisional was filed off 11/988,888 apart from the 13/341,051 and 13/718,348 continuations.
4. Reconcile the two "current dates" (April 26, 2026 vs. September 24, 2026), because expiration on July 18, 2026 changes the status from "in force" to "expired" across that boundary.

Sources consulted: Google Patents US 8,362,960 (legal status, family, continuity data); issued-patent PDF (US008362960B2) front matter; FreePatentsOnline US 8,362,960; the 13/718,348 filing/continuity record (which recites the full CON/371 chain); Google Patents US 8,810,458 family entry; and the PTAB IPR2026-00341 case record (Resmed Corp. v. Fractus, S.A.).

Defensive Disclosure: US Patent 8,362,960 - Handheld Device with Two Antennas, and Method of Enhancing the Isolation Between the Antennas

Date: April 26, 2026

This Defensive Disclosure document outlines derivative variations and extensions of the technologies claimed in US Patent 8,362,960. The purpose is to establish prior art, rendering obvious or non-novel future incremental improvements by competitors. This document leverages the core inventive concepts of dual-antenna handheld devices, slot antennas, and various isolation enhancement techniques, expanding them across diverse technical axes.

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Derivative Variations for Independent Claim 1: Handheld Device with Slot Antenna and Parallel Orientation for Isolation

Core Claim 1: A handheld device comprising a first antenna arranged to operate in at least a first frequency band, and a second antenna arranged to operate in at least a second frequency band, wherein said second frequency band is different from said first frequency band, characterized in that the second antenna comprises a slot antenna comprising at least one slot in at least one conductive layer, and in that the second antenna is arranged substantially parallel to electric currents excited on at least a portion of a printed circuit board (PCB) of the handheld device by a radiating mode of said first antenna for enhancing isolation between the first antenna and the second antenna.

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1. Material & Component Substitution

Derivative 1.1: Multi-Layer Ceramic Substrate with Embedded Slot Antenna

• Enabling Description: A handheld communication module for 5G mmWave applications, utilizing a multi-layer ceramic (MLC) substrate (e.g., low-temperature co-fired ceramic, LTCC) instead of a standard FR-4 PCB. The first antenna (e.g., a patch array) is implemented on the top layer, operating in the 28 GHz band. The second antenna, a miniaturized slot antenna, is fabricated by etching a slot into an internal conductive layer of the MLC substrate, operating in the 60 GHz band. The MLC substrate offers superior dielectric properties ($\epsilon_r \approx 6-10$) and reduced loss tangent, allowing for highly integrated, compact structures. The slot antenna's major axis is oriented to be substantially parallel (within $\pm 15^\circ$) to the dominant surface currents excited on the adjacent ground plane layer by the 28 GHz patch array. This parallel orientation, within the rigid, high-density MLC stack, significantly reduces mutual coupling by minimizing direct field interaction. Feedlines are integrated within the MLC layers via vertical vias.

graph TD
    A[5G Handheld Module] --> B(MLC Substrate)
    B --> C{Top Layer}
    B --> D{Internal Layer 1}
    B --> E{Internal Layer 2}
    B --> F{Bottom Layer}
    C -- 28 GHz Patch Array --> G(First Antenna)
    E -- 60 GHz Slot Antenna --> H(Second Antenna)
    G & H -- Optimized Orientation --> I(Enhanced Isolation)
    D -- Ground Plane --> J(Surface Currents)
    H -- Parallel to --> J

Derivative 1.2: Flexible PCB with Conductive Polymer Slot Antenna

• Enabling Description: A wearable handheld device (e.g., smart wristband) incorporates a flexible printed circuit board (FPCB) made of polyimide. The first antenna, a flexible dipole operating at 2.4 GHz (Bluetooth/Wi-Fi), is printed using silver nanoparticle conductive ink on the FPCB. The second antenna is a conformable slot antenna, where the slot is formed by laser ablation of a thin layer of highly conductive polymer (e.g., PEDOT:PSS composite with high conductivity additives) integrated into a different region of the FPCB, resonating at 5.8 GHz. The FPCB's inherent flexibility allows for integration into non-planar surfaces. The flexible slot antenna is positioned such that its longitudinal axis remains substantially parallel (within $\pm 20^\circ$) to the primary electric current paths induced on the FPCB's ground plane by the 2.4 GHz dipole, even as the device flexes. This maintains isolation performance in dynamic configurations.

flowchart TD
    A[Wearable Device] --> B(Flexible PCB)
    B -- Polyimide Substrate --> C(Ground Plane Layer)
    B -- Conductive Polymer Layer --> D(Slot Ablation)
    D --> E(Second Antenna: Flexible Slot)
    B -- Silver Ink Printing --> F(First Antenna: Flexible Dipole)
    C -- Induced Currents --> G(Current Paths on FPCB)
    E -- Oriented Parallel To --> G
    F & E -- Achieves --> H(Dynamic Isolation)

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2. Operational Parameter Expansion

Derivative 2.1: Terahertz (THz) On-Chip Communication with Integrated Slot Isolation

• Enabling Description: A high-speed data interconnect for intra-chip communication operates in the 300 GHz to 1 THz band. The first antenna is a plasmonic dipole array for THz transmission, fabricated directly on a silicon-on-insulator (SOI) substrate. The second antenna is a sub-THz slot antenna (e.g., a resonant slot etched in the metal interconnect layer), operating at 600 GHz, acting as a local wireless link. Due to the extremely short wavelengths, the entire system, including the slot antenna and its isolation features, is integrated on-chip. The slot antenna's orientation is precisely controlled via e-beam lithography to align its equivalent magnetic current (induced by the THz slot) substantially parallel (within $\pm 5^\circ$) to the localized electric currents generated on the underlying ground plane (e.g., a heavily doped silicon layer or buried metal layer) by the THz plasmonic dipole. This precise, nanoscale orientation is critical for achieving even modest isolation (e.g., -10 dB) in the highly coupled on-chip environment.

componentDiagram
    [Chip Module] --> [THz Transmitter]
    [Chip Module] --> [THz Receiver]
    [THz Transmitter] -- 300-1000 GHz --> [THz Receiver]
    [THz Transmitter] --> [First Antenna (Plasmonic Dipole)]
    [THz Receiver] --> [Second Antenna (Sub-THz Slot)]
    [Chip Module] --> [SOI Substrate]
    [SOI Substrate] .. Ground Plane ..> [First Antenna (Plasmonic Dipole)]
    [SOI Substrate] .. Ground Plane ..> [Second Antenna (Sub-THz Slot)]
    [First Antenna (Plasmonic Dipole)] --> [Local Electric Currents]
    [Second Antenna (Sub-THz Slot)] -- Aligned Parallel to --> [Local Electric Currents]
    [Chip Module] --> [Enhanced On-Chip Isolation]

Derivative 2.2: Industrial-Scale RF Identification (RFID) System with Large-Format Slot Antennas

• Enabling Description: A wide-area industrial asset tracking system, deployed across a large factory floor (e.g., hundreds of square meters), operating in the UHF RFID band (902-928 MHz). Multiple spatially distributed reader antennas are required. The first antenna is a circularly polarized patch antenna integrated into a ceiling panel, covering a broad area. The second antenna is a linear slot antenna, several meters in length, etched into large conductive sheets (e.g., aluminum sheets forming part of the building infrastructure or a conductive floor tile array), operating at a slightly shifted frequency (e.g., 868 MHz for international compliance) or a different polarization mode. The conductive sheet acts as the ground plane. The large slot antenna is oriented such that its equivalent magnetic current direction is parallel (within $\pm 30^\circ$) to the dominant electric current flows induced on the extensive ground plane by the first (patch) antenna. This arrangement minimizes inter-reader interference across the vast industrial environment, allowing for dense reader deployment.

flowchart TD
    A[Industrial Asset Tracking] --> B(Factory Floor)
    B --> C[Ceiling Panel]
    C --> D(First Antenna: UHF Patch)
    B --> E[Conductive Floor Tiles]
    E --> F(Second Antenna: Large Slot Array)
    F -- Etched into --> G(Large Ground Plane)
    D -- Induces --> H(Electric Currents on G)
    F -- Aligned Parallel to --> H
    A -- Achieves --> I(Reduced Inter-Reader Interference)

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3. Cross-Domain Application

Derivative 3.1: Automotive V2X Communication with Integrated Slot Isolation

• Enabling Description: An advanced automotive communication system for Vehicle-to-Everything (V2X) applications. The vehicle's roof houses a first antenna, a multi-band GNSS/Cellular antenna operating in cellular bands (e.g., 700 MHz, 1.8 GHz) and GNSS bands (e.g., 1.575 GHz). A second antenna, a dedicated V2X slot antenna (e.g., DSRC at 5.9 GHz or C-V2X in cellular bands), is integrated into the vehicle's metal body panel (which serves as the ground plane) or an adjacent composite structure with a conductive backing. The V2X slot antenna is strategically placed on the vehicle chassis, such that its radiating slot is substantially parallel (within $\pm 25^\circ$) to the electric currents excited on the vehicle's metallic body by the cellular/GNSS antenna. This arrangement mitigates self-interference, ensuring robust V2X communication critical for autonomous driving functions.

stateDiagram
    state "Automotive V2X System" as V2X
    V2X --> "Vehicle Body (Ground Plane)" as Body
    Body --> "First Antenna (GNSS/Cellular)" as Ant1
    Body --> "Second Antenna (V2X Slot)" as Ant2
    Ant1 --> "Electric Currents on Body" as ECurrents
    Ant2 --> "Aligned Parallel to ECurrents"
    Ant1 --> "First Freq Band"
    Ant2 --> "Second Freq Band"
    "Aligned Parallel to ECurrents" --> "Enhanced Isolation"
    "Enhanced Isolation" --> "Reliable V2X Communication"

Derivative 3.2: Smart Agriculture Drone with Multi-Spectral Sensor Antenna Isolation

• Enabling Description: A smart agriculture drone utilizes a multi-spectral imaging payload for crop health monitoring. A first antenna, a standard telemetry and control antenna (e.g., 900 MHz ISM band), is mounted on the drone's composite frame. The second antenna is a compact slot antenna, etched into a conductive layer within the multi-spectral sensor housing, operating in a different band (e.g., 5.8 GHz for high-bandwidth data offload or a dedicated short-range communication link). The slot antenna's major axis is oriented parallel (within $\pm 20^\circ$) to the electric currents induced on the drone's conductive frame (serving as a ground plane) by the telemetry antenna. This optimized orientation minimizes interference from the drone's control systems into the sensitive data downlink, ensuring clear and accurate multi-spectral data transmission from the sensor.

sequenceDiagram
    participant DroneFrame as Drone Frame
    participant TelemetryAntenna as Telemetry Antenna
    participant SensorHousing as Sensor Housing
    participant SlotAntenna as Slot Antenna
    TelemetryAntenna->DroneFrame: Excites Electric Currents
    SlotAntenna->DroneFrame: Slot antenna integrated with ground plane
    Note over SlotAntenna,DroneFrame: Slot aligned parallel to currents
    TelemetryAntenna->TelemetryAntenna: Transmits Control (900MHz)
    SlotAntenna->SensorHousing: Transmits Sensor Data (5.8GHz)
    DroneFrame->TelemetryAntenna: Provides Ground
    DroneFrame->SlotAntenna: Provides Ground
    TelemetryAntenna->SlotAntenna: Reduced Mutual Coupling
    SlotAntenna->SensorHousing: Clean Data Transmission

---

4. Integration with Emerging Tech

Derivative 4.1: AI-Driven Dynamic Slot Reconfigurability for Adaptive Isolation

• Enabling Description: A handheld device integrates a cognitive radio module and a reconfigurable slot antenna. The first antenna is a wideband cellular antenna. The second antenna is a slot antenna etched into the PCB ground plane, but its slot geometry includes embedded micro-electromechanical systems (MEMS) switches, varactor diodes, or phase-change materials (PCMs) that can dynamically alter its effective electrical length and topology. An AI-powered controller continuously monitors the wireless environment for interference and mutual coupling levels between the two antennas using real-time channel state information (CSI) obtained from an RF front-end with power detectors and spectrum analyzers. The AI algorithm predicts optimal slot configurations (e.g., modifying slot width, activating parasitic stubs within the slot, or altering the physical dimensions of resonant elements within the slot) to maintain isolation above a predefined threshold (e.g., -25 dB) across varying operating bands and user environments. The AI then sends control signals to the MEMS/varactors/PCMs to reconfigure the slot antenna's geometry. The system prioritizes maintaining the parallel orientation of the slot's equivalent magnetic current to the first antenna's induced electric currents whenever possible, making fine-grain adjustments to the slot's effective longitudinal axis through localized reconfigurations.

flowchart TD
    A[Handheld Device] --> B(RF Front-End)
    B --> C(First Antenna: Cellular)
    B --> D(Second Antenna: Reconfigurable Slot)
    D -- MEMS/Varactors/PCMs --> E(Dynamic Slot Geometry)
    B -- Channel State Info (CSI) --> F(AI Controller)
    F -- Real-time Analysis --> G(Interference & Coupling Monitor)
    G --> H(Optimal Configuration Prediction)
    H -- Control Signals --> E
    E -- Aligned Parallel to --> I(PCB Electric Currents from C)
    I --> J(Adaptive Isolation Enhancement)

Derivative 4.2: IoT Sensor Network for Real-time Isolation Monitoring and Antenna Re-selection

• Enabling Description: An industrial IoT gateway device incorporates a primary LoRaWAN antenna (first antenna, 868 MHz) and a secondary Wi-Fi antenna (second antenna, 2.4 GHz slot antenna). The PCB of the gateway is instrumented with miniature electromagnetic field (EMF) sensors (e.g., miniaturized electric and magnetic field probes) placed at strategic locations around both antennas and on the common ground plane. These IoT sensors continuously stream real-time EMF data to a local edge computing unit. The edge unit, running a lightweight machine learning algorithm, analyzes the EMF patterns to infer the actual surface current distribution on the PCB and the instantaneous isolation levels between the two antennas. If isolation drops below a critical threshold, the system either: (a) triggers a warning, (b) dynamically re-tunes the Wi-Fi slot antenna (if it includes tunable components) to shift its resonance, or (c) switches to an alternative, physically separated Wi-Fi slot antenna (from a pre-installed array) that currently exhibits better isolation based on the monitored current distribution. The initial deployment ensures the primary Wi-Fi slot antenna is oriented parallel to the predicted LoRaWAN-induced currents.

graph TD
    A[IoT Gateway Device] --> B(LoRaWAN Antenna (First))
    A --> C(Wi-Fi Slot Antenna (Second))
    A --> D(PCB Ground Plane)
    D -- Embedded EMF Sensors --> E(Real-time EMF Data Stream)
    E --> F(Edge Computing Unit)
    F -- ML Algorithm --> G(Isolation & Current Analysis)
    G -- If Low Isolation --> H{Action?}
    H -- Yes --> I(Re-tune Slot / Switch Antenna)
    C -- Initial Parallel Orientation --> D
    B -- Induces Currents --> D

---

5. The "Inverse" or Failure Mode

Derivative 5.1: Controlled Coupling Handheld for Resonant Wireless Power Transfer

• Enabling Description: A specialized handheld device is designed to intentionally achieve controlled electromagnetic coupling between its two antennas for resonant wireless power transfer (RWPT) or secure short-range data beaming. The first "antenna" is a resonant inductive loop for RWPT at 13.56 MHz (NFC band). The second "antenna" is a slot antenna etched into the PCB, operating at the same 13.56 MHz. Instead of parallel orientation for isolation, the slot antenna is deliberately oriented orthogonal (within $\pm 10^\circ$) to the primary electric currents excited on the PCB by the inductive loop. Furthermore, the slot's geometry and placement are optimized to maximize the inductive coupling factor, effectively turning the slot into a receive coil or an energy harvesting element from the first antenna. This "inverse" design leverages the principles of electromagnetic coupling to achieve a desired function (power/data transfer) rather than isolation.

flowchart TD
    A[Handheld Device] --> B(First Element: Resonant Inductive Loop)
    A --> C(Second Element: Slot Antenna)
    A --> D(PCB)
    B -- Excites --> E(Electric Currents on D)
    C -- Deliberately Orthogonal to --> E
    E --> F(Maximized Inductive Coupling)
    F --> G(Resonant Wireless Power Transfer / Data Beaming)

Derivative 5.2: Low-Power "Beacon" Mode with Degraded Isolation

• Enabling Description: A handheld device for emergency communication features a standard cellular antenna (first antenna) and a low-power, wide-area network (LPWAN) slot antenna (second antenna) for emergency beaconing (e.g., Satellite IoT like Inmarsat or Iridium). In normal operation, isolation between these antennas is enhanced as per Claim 1. However, in a "low-power beacon" or "emergency-only" mode, the device prioritizes minimal power consumption over optimal isolation. The cellular module is powered down. The LPWAN slot antenna transmits periodically at reduced power (e.g., -10 dBm). The system deactivates any active isolation circuits or reconfigurable elements, and the strict parallel orientation requirement for the slot antenna is relaxed (e.g., isolation can drop to -15 dB from a nominal -25 dB). This allows for simplified power management, reduced computational load, and potentially smaller form factors by eliminating active isolation components or allowing for slightly suboptimal antenna placement, accepting degraded isolation as a trade-off for extended battery life in critical situations.

stateDiagram
    state "Normal Operation" as Normal
    state "Low-Power Beacon Mode" as Beacon
    Normal --> Beacon: Emergency Detected / Low Battery
    Beacon --> Normal: Emergency Cleared / Power Restored

    Normal: High Isolation (-25dB)
    Normal: Active Isolation Management
    Normal: Strict Parallel Alignment
    Normal --> FirstAntenna_Active(Cellular Active)
    Normal --> SecondAntenna_Active(LPWAN Active, High Isolation)

    Beacon: Degraded Isolation (-15dB)
    Beacon: Passive Isolation
    Beacon: Relaxed Alignment Constraints
    Beacon --> FirstAntenna_Inactive(Cellular Inactive)
    Beacon --> SecondAntenna_Beacon(LPWAN Active, Low Power)

    FirstAntenna_Active --> PCB_Currents(Electric Currents on PCB)
    SecondAntenna_Active --> Parallel_Alignment(Parallel to PCB_Currents)
    Parallel_Alignment --> Isolation_Enhanced(Isolation Enhanced)

    SecondAntenna_Beacon --> Relaxed_Alignment(Relaxed Parallel Alignment)
    Relaxed_Alignment --> Isolation_Degraded(Isolation Degraded)

---

Derivative Variations for Independent Claim 15: Method of Modifying First Antenna Geometry for Isolation

Core Claim 15: A method of enhancing the isolation between a first antenna and a second antenna in a handheld device, the method comprising the step of modifying a geometrical feature of said first antenna to make said geometrical feature electrically longer or shorter to shift an associated resonance frequency away from an operating band of said second antenna for reducing strong electromagnetic coupling between the first antenna and the second antenna.

---

1. Material & Component Substitution

Derivative 15.1: Dynamic Resonance Shifting using Liquid Metal Microfluidics

• Enabling Description: A method for enhancing isolation involves integrating microfluidic channels containing liquid metal (e.g., eutectic gallium-indium, EGaIn) within the radiating elements of the first antenna (e.g., an inverted-F antenna, IFA). The geometry of a critical arm of the IFA is defined by these channels. By applying pneumatic pressure or electro-wetting, the volume and shape of the liquid metal within the channels can be precisely controlled, effectively lengthening or shortening the antenna's conductive path. This dynamic geometric modification shifts the IFA's associated resonance frequency. For instance, if a spurious resonance of the IFA is found to overlap with the operating band of a nearby Wi-Fi slot antenna, the liquid metal is reconfigured to electrically shorten the IFA arm, shifting the problematic resonance upwards and away from the Wi-Fi band, thereby reducing coupling. This allows for continuous and reversible tuning.

flowchart TD
    A[Monitor Coupling] --> B{Overlap Detected?}
    B -- Yes --> C[Identify First Antenna Resonance]
    C --> D[Calculate Desired Shift]
    D --> E[Control Microfluidic Pumps/Electro-wetting]
    E --> F[Change Liquid Metal Geometry in First Antenna Arm]
    F --> G[Shift First Antenna Resonance]
    G --> H[Reduce Coupling]
    B -- No --> A

Derivative 15.2: Phase-Change Material (PCM) Reconfiguration for Antenna Length Adjustment

• Enabling Description: This method utilizes a first antenna with a radiating element partially covered by a phase-change material (e.g., Vanadium Dioxide, VO2, or specific chalcogenide glasses) that transitions between conductive and insulating states upon thermal or electrical stimulus. A geometric feature of this first antenna (e.g., a shorting stub or a parasitic strip) is designed such that its effective electrical length is altered when the PCM changes state. For example, in its insulating state, the PCM disconnects a portion of the stub, electrically shortening it; in its conductive state, it connects the portion, making it electrically longer. By applying a controlled heat source (e.g., a resistive heater) or electrical bias, the PCM state is switched. This shifts the associated resonance frequency of the first antenna away from the second antenna's operating band. For instance, to reduce interference with a Bluetooth slot antenna, the PCM on a specific trace of the cellular first antenna is heated, causing it to become conductive and extend the electrical path, lowering a problematic cellular resonance below the Bluetooth band.

stateDiagram
    state "Initial State (Low Coupling)" as Initial
    state "High Coupling Detected" as HighCoupling
    state "Resonance Shifted (Reduced Coupling)" as Shifted

    Initial --> HighCoupling: Coupling Exceeds Threshold
    HighCoupling --> Shifted: PCM Activation / Deactivation
    Shifted --> Initial: Coupling Stabilized / Revert

    state "PCM Control" {
        HighCoupling --> "Apply Stimulus (Heat/Bias)" as Stimulus
        Stimulus --> "PCM State Change (Conductive/Insulating)" as StateChange
        StateChange --> "Modify Antenna Electrical Length" as LengthMod
        LengthMod --> "Shift First Antenna Resonance" as ShiftRes
    }
    ShiftRes --> Shifted

---

2. Operational Parameter Expansion

Derivative 15.3: Ultra-Wideband (UWB) Antenna Shaping for Notch Filter Realization

• Enabling Description: For a handheld device operating with a primary UWB antenna (first antenna, e.g., 3-10 GHz) and a secondary narrowband Wi-Fi slot antenna (second antenna, e.g., 5.2 GHz), a method to enhance isolation involves shaping a geometrical feature of the UWB antenna to create a deep notch at the Wi-Fi frequency. This is achieved by introducing a meticulously designed parasitic element or a specifically shaped slot (e.g., an embedded U-slot or E-slot) into the ground plane or radiating element of the UWB antenna itself. The dimensions of this feature are precisely calculated to resonate at the center frequency of the Wi-Fi band, effectively creating a high-impedance path or a filter that suppresses radiation from the UWB antenna at that specific frequency, thereby reducing its coupling into the Wi-Fi slot antenna. The modification is permanent and optimized during antenna design.

graph TD
    A[Handheld Device] --> B(UWB Antenna (First))
    A --> C(Wi-Fi Slot Antenna (Second))
    B -- Integrate --> D(Geometric Feature: Notch Resonator)
    D -- Tuned to --> E(Wi-Fi Center Frequency)
    D --> F(Creates High Impedance Path/Filter)
    B -- Reduce Radiation @ E --> G(Reduced Coupling to C)
    B -- Continue UWB Operation --> H(Broadband Functionality)

Derivative 15.4: Adaptive Aperture Tuning for Satellite Handset Inter-band Isolation

• Enabling Description: A satellite handheld phone incorporates a first antenna, a complex multi-band active array antenna for satellite communication (e.g., L-band for voice, Ka-band for data). The second antenna is a cellular slot antenna operating in conventional terrestrial bands (e.g., 1.8 GHz). To enhance isolation, the method focuses on the aperture of the first (satellite array) antenna. Specific elements within the array's aperture (e.g., small reconfigurable patches or tunable parasitic strips surrounding the main radiating elements) are dynamically reconfigured. For instance, MEMS switches or RF-MEMS varactors are used to effectively change the "electrical size" or impedance of these aperture-defining features. If a specific Ka-band satellite resonance mode (e.g., around 28 GHz) causes coupling with a nearby 5G mmWave slot antenna (as a second antenna), the aperture elements are tuned to shift this problematic Ka-band resonance slightly away (e.g., by 500 MHz) from the mmWave band, while maintaining overall satellite link performance. This sophisticated approach prevents the generation of spurious radiation patterns that could interfere with the second antenna.

classDiagram
    class SatelliteHandset {
        +FirstAntenna: Active Array
        +SecondAntenna: Cellular Slot
        +ControlUnit
    }
    class ActiveArray {
        -MainRadiatingElements
        -ReconfigurableApertureElements
        -RFMEMSSwitches
        -VaractorDiodes
        +tuneAperture(targetFreqShift)
    }
    class CellularSlot {
        +OperatingBand
    }
    class ControlUnit {
        +monitorCoupling()
        +adjustFirstAntenna(targetFreq)
    }
    SatelliteHandset --* ActiveArray
    SatelliteHandset --* CellularSlot
    SatelliteHandset --* ControlUnit
    ControlUnit --> ActiveArray: calls tuneAperture()
    ActiveArray <--> ReconfigurableApertureElements
    ReconfigurableApertureElements <--> RFMEMSSwitches
    ReconfigurableApertureElements <--> VaractorDiodes

---

3. Cross-Domain Application

Derivative 15.5: Medical Implantable Antenna with Bio-Adaptive Resonance Shifting

• Enabling Description: A method for isolation enhancement in a medical implantable device, such as a smart pacemaker or neural interface. The first antenna is an ultra-miniaturized flexible dipole for short-range wireless power and data transfer (e.g., 402-405 MHz MICS band). The second antenna is a co-located slot antenna for secure long-range telemetry (e.g., 2.4 GHz ISM band). The challenge is that tissue properties (dielectric constant, conductivity) can dynamically change due to hydration, temperature, or pathological conditions, shifting the first antenna's resonance and causing coupling. To address this, a geometrical feature of the first antenna (e.g., a resonant stub built into its structure) is designed with embedded micro-heaters or miniature electromechanical actuators. When real-time bio-impedance sensors detect a tissue change causing the MICS antenna's resonance to drift into the 2.4 GHz band's harmonics or sub-harmonics, the actuators/heaters modify the stub's effective length. This shifts the MICS resonance back to its intended band or away from the problematic harmonic, maintaining isolation for the 2.4 GHz telemetry.

flowchart TD
    A[Implantable Device] --> B(MICS Antenna (First))
    A --> C(ISM Slot Antenna (Second))
    A --> D(Bio-Impedance Sensors)
    D -- Real-time Data --> E(Controller)
    B -- Includes --> F(Reconfigurable Resonant Stub)
    F -- Actuators/Heaters --> G(Modify Stub Length)
    E -- Detects Resonance Drift --> H{Coupling Risk?}
    H -- Yes --> E
    E -- Sends Command --> G
    G --> I(Shift MICS Resonance)
    I --> J(Enhance Isolation)

Derivative 15.6: Smart Infrastructure Sensor Node with Environmental Adaptive Antenna Tuning

• Enabling Description: A method for optimizing isolation in smart city infrastructure sensor nodes (e.g., embedded in lampposts or bridges). A first antenna (e.g., a cellular IoT antenna for NB-IoT or LTE-M at 700 MHz) is integrated into the node. A second antenna, a Wi-Fi slot antenna (e.g., 2.4 GHz), provides local connectivity. The geometrical feature of the cellular IoT antenna (e.g., a tunable loading element or a configurable ground plane extension) is made electrically longer or shorter. This tuning is not based on other antennas' operating bands but on the surrounding environment. Seasonal changes (e.g., foliage density affecting cellular propagation, accumulation of snow/ice) or proximity to large metallic structures (e.g., trucks, temporary construction) can detune the cellular antenna, causing spurious resonances to emerge and couple into the Wi-Fi slot. Environmental sensors (e.g., optical, proximity, temperature) provide input to an adaptive tuning algorithm, which then signals to RF MEMS switches or varactors on the cellular antenna to adjust its loading, shifting the problematic resonance away from the Wi-Fi band and restoring isolation.

sequenceDiagram
    participant EnvSensors as Environmental Sensors
    participant Controller as Adaptive Controller
    participant CellularAntenna as Cellular Antenna (First)
    participant WiFiSlotAntenna as Wi-Fi Slot Antenna (Second)
    participant StructuralGround as Structural Ground Plane
    EnvSensors->Controller: Report Environmental Changes
    Controller->Controller: Analyze Impact on Cellular Resonance
    alt Spurious Resonance Overlaps Wi-Fi
        Controller->CellularAntenna: Adjust Tunable Loading Element
        CellularAntenna->CellularAntenna: Electrically Lengthen/Shorten Feature
        CellularAntenna->CellularAntenna: Shift Cellular Resonance Freq
        CellularAntenna->WiFiSlotAntenna: Reduced Coupling
    else No Overlap
        Controller->Controller: Continue Monitoring
    end
    CellularAntenna->StructuralGround: Operates with Ground
    WiFiSlotAntenna->StructuralGround: Operates with Ground

---

4. Integration with Emerging Tech

Derivative 15.7: Digital Twin-Based Predictive Resonance Management for High-Density Systems

• Enabling Description: In a high-density, multi-radio handheld device (e.g., a gaming console with multiple wireless interfaces), a digital twin of the device's antenna system (including the first cellular antenna and the second Wi-Fi/Bluetooth slot antennas) is maintained in real-time. This digital twin precisely models the electromagnetic environment, PCB current distributions, and antenna performance characteristics. When a new wireless service is activated or an environmental change (e.g., hand proximity) is detected, the digital twin predicts potential shifts in the cellular antenna's resonance frequencies and evaluates the likelihood of coupling with the slot antennas. Before actual coupling occurs, the digital twin suggests optimal geometric modifications (e.g., reconfiguring active antenna elements via a liquid crystal polymer substrate or MEMS-actuated stubs) to the first antenna, pre-emptively shifting its resonances away from the operating bands of the second antennas. This predictive approach minimizes downtime and ensures continuous high isolation.

graph TD
    A[Physical Handheld Device] --> B(First Antenna: Cellular)
    A --> C(Second Antennas: Wi-Fi/BT Slots)
    A -- Real-time Data (Sensors, RF) --> D(Digital Twin Model)
    D -- Predictive Simulation --> E(Potential Resonance Overlap)
    E -- Optimization Algorithm --> F(Optimal Geometric Modification)
    F -- Control Commands --> G(Reconfigurable Elements in B)
    G --> H(Pre-emptive Resonance Shift)
    H --> I(Maintained High Isolation)

Derivative 15.8: Blockchain-Verified Antenna Configuration History for Regulatory Compliance

• Enabling Description: A method for maintaining regulatory compliance in specialized handheld devices (e.g., mission-critical communications). The device's first antenna (a configurable military-band antenna) includes actively reconfigurable elements (e.g., PIN diodes, MEMS switches) that can modify its electrical length to tune its resonance. Each time a geometric modification is made to shift a resonance frequency (to avoid coupling with a co-located secure data link slot antenna), the specific configuration parameters (e.g., switch states, control voltages) and the resulting resonance shift are recorded. This data, along with a timestamp and the measured isolation improvement, is cryptographically signed and appended to a distributed ledger (blockchain). This immutable record provides verifiable proof of compliant operation and antenna performance history, particularly important for demonstrating adherence to spectrum usage regulations and avoiding unintended interference.

sequenceDiagram
    participant HandheldDevice as Handheld Device
    participant FirstAntenna as First Antenna (Configurable)
    participant SecondAntenna as Second Antenna (Slot)
    participant RFModule as RF Module
    participant BlockchainNetwork as Blockchain Network
    RFModule->FirstAntenna: Detect coupling risk
    RFModule->FirstAntenna: Initiate geometric modification (electrically length/shorten)
    FirstAntenna->RFModule: Report new configuration & resonance shift
    RFModule->SecondAntenna: Measure improved isolation
    RFModule->BlockchainNetwork: Record config, shift, isolation, timestamp (signed)
    BlockchainNetwork->BlockchainNetwork: Verify and append to ledger
    note over BlockchainNetwork: Immutable, verifiable record of compliance

---

Derivative Variations for Independent Claim 20: Method of Modifying PCB Geometry for Isolation

Core Claim 20: A method of enhancing the isolation between a first antenna and a second antenna in a handheld device, the method comprising the step of modifying the geometry of the PCB of said handheld device to introduce on said PCB a feature able to increase the isolation between the first antenna and the second antenna in at least one frequency band.

---

1. Material & Component Substitution

Derivative 20.1: Metamaterial-Enhanced Ground Plane Isolation Features

• Enabling Description: Instead of simple slots or conductive strips, this method modifies the PCB geometry by etching or printing sub-wavelength metamaterial structures (e.g., split-ring resonators, complementary split-ring resonators, or mushroom-type structures) directly into the ground plane of the handheld device. These metamaterial unit cells are arranged in a periodic or aperiodic array in the region between the first (e.g., PIFA) and second (e.g., Wi-Fi slot) antennas. The metamaterial structures are designed to exhibit a stop-band characteristic at the problematic coupling frequency band (e.g., a spurious resonance of the PIFA that overlaps the Wi-Fi band). This creates an electromagnetic bandgap (EBG) or artificial magnetic conductor (AMC) surface that locally suppresses surface wave propagation and unwanted common-mode currents on the PCB, thereby significantly increasing isolation. The metamaterial structures can be fabricated using standard PCB etching techniques but require precise design based on the operating wavelength.

graph TD
    A[Handheld Device] --> B(First Antenna)
    A --> C(Second Antenna)
    A --> D(PCB Ground Plane)
    D -- Integrate --> E(Metamaterial Isolation Structure)
    E -- Designed for --> F(Stop-band at Coupling Freq)
    F --> G(Suppress Surface Waves/Currents)
    G --> H(Enhanced Isolation Between B and C)

Derivative 20.2: 3D Printed Multi-Layer PCB with Integrated Conductive Polymer Walls

• Enabling Description: A method using advanced additive manufacturing (3D printing) for PCBs. The handheld device's PCB is fabricated as a multi-layer structure where conductive traces, dielectric layers, and isolating features are built up layer-by-layer. To enhance isolation, the PCB geometry is modified by printing vertical conductive polymer walls (e.g., graphene-infused polymer or silver-loaded resin) that act as electromagnetic fences or shielding walls between the first (e.g., cellular patch) and second (e.g., Bluetooth slot) antennas. These walls are integrated directly into the dielectric substrate layers, extending from the ground plane up to or above the antenna layers. The height and thickness of these walls are optimized to create a physical and electromagnetic barrier at the coupling frequency, effectively channeling surface currents and preventing direct line-of-sight coupling.

componentDiagram
    [Handheld Device] --> [3D Printed PCB]
    [3D Printed PCB] --> [First Antenna (Cellular Patch)]
    [3D Printed PCB] --> [Second Antenna (Bluetooth Slot)]
    [3D Printed PCB] --> [Ground Plane Layer]
    [Ground Plane Layer] .. Forms Base ..> [Conductive Polymer Walls]
    [Conductive Polymer Walls] .. Separate ..> [First Antenna (Cellular Patch)]
    [Conductive Polymer Walls] .. Separate ..> [Second Antenna (Bluetooth Slot)]
    [Conductive Polymer Walls] --> [Electromagnetic Shielding]
    [Electromagnetic Shielding] --> [Enhanced Isolation]

---

2. Operational Parameter Expansion

Derivative 20.3: Cryogenic Operating Environment with Superconducting Isolation Slots

• Enabling Description: For scientific or specialized computing handheld devices operating in cryogenic environments (e.g., temperatures below 77K), a method to enhance isolation involves fabricating the PCB with superconducting materials (e.g., YBCO thin films on a sapphire or lanthanum aluminate substrate) for the ground plane. The PCB geometry is modified by laser-ablating narrow slots into this superconducting ground plane between the first (e.g., high-frequency quantum computing control antenna) and second (e.g., cryogenic sensor telemetry slot antenna) antennas. At cryogenic temperatures, these slots leverage the zero electrical resistance of the superconducting ground plane to create extremely sharp, high-Q resonant features. These superconducting isolation slots are precisely tuned to resonate at a frequency that presents an exceptionally high impedance path to parasitic currents, effectively eliminating coupling at that frequency with minimal resistive loss, vastly surpassing the performance of traditional copper slots at room temperature.

stateDiagram
    state "Room Temp (Initial)" as RoomTemp
    state "Cryogenic Operation" as CryoOp
    RoomTemp --> CryoOp: Cooling Down
    CryoOp --> RoomTemp: Warming Up

    CryoOp: Superconducting Ground Plane
    CryoOp: Laser-Ablated Superconducting Slots
    CryoOp: Zero-Resistance High-Q Resonance
    CryoOp --> FirstAntenna_Cryo(Quantum Control Antenna)
    CryoOp --> SecondAntenna_Cryo(Cryo Sensor Slot Antenna)
    FirstAntenna_Cryo --> Superconducting_Slots(Superconducting Isolation Slots)
    SecondAntenna_Cryo --> Superconducting_Slots
    Superconducting_Slots --> Ultra_High_Isolation(Ultra-High Isolation)

Derivative 20.4: Millimeter-Wave (mmWave) PCB with Sub-THz Resonant Etched Structures

• Enabling Description: In handheld devices designed for mmWave (e.g., 60 GHz WiGig) and sub-THz communications, the PCB is fabricated using advanced low-loss dielectric materials (e.g., Liquid Crystal Polymer, LCP, or PTFE-based laminates). To enhance isolation between a 60 GHz patch antenna (first antenna) and a 120 GHz sub-THz slot antenna (second antenna), the PCB geometry is modified by etching resonant features directly into the ground plane and adjacent signal layers. These features include precisely dimensioned open-ended stubs, resonant slot arrays, or electromagnetic bandgap (EBG) structures designed to resonate at specific mmWave and sub-THz frequencies. For example, a series of narrow, shorted conductive lines are etched into the ground plane, forming quarter-wave resonant traps at the 60 GHz frequency, effectively creating a "wall" of high impedance that blocks surface waves and common-mode currents from propagating between the two antennas at the specific interfering frequency, leading to enhanced isolation.

flowchart TD
    A[Handheld Device] --> B(mmWave PCB)
    B --> C(60 GHz Patch (First Ant))
    B --> D(120 GHz Slot (Second Ant))
    B -- Low-Loss Dielectric --> E(Ground Plane / Signal Layers)
    E -- Etch --> F(Resonant Traps / EBG Structures)
    F -- Tuned to --> G(Interfering mmWave/Sub-THz Freqs)
    G --> H(Block Surface Waves)
    H --> I(Enhanced Isolation)

---

3. Cross-Domain Application

Derivative 20.5: Avionics Control Unit with Integrated Ground Plane Isolation for EMI Hardening

• Enabling Description: In a high-reliability avionics control unit (ACU) for aircraft, electromagnetic interference (EMI) between densely packed RF modules is a critical concern. The ACU houses a primary flight control data link antenna (first antenna, e.g., L-band for GPS/datalink) and a secondary cabin Wi-Fi antenna (second antenna, e.g., 2.4 GHz slot antenna). The PCB geometry of the ACU is modified by fabricating a multi-layered board with embedded, highly-conductive shielding vias forming continuous "via fences" around and between critical RF sections. Additionally, the ground planes are patterned with precisely designed resonant slots and shorted microstrip stubs tuned to create high-impedance paths at specific interference frequencies (e.g., harmonics of the L-band signal that fall into the Wi-Fi band). This robust PCB modification actively hardens the system against EMI, ensuring signal integrity for both essential flight controls and passenger connectivity.

classDiagram
    class AvionicsControlUnit {
        +PrimaryRFModule
        +SecondaryRFModule
        +MultiLayerPCB
    }
    class MultiLayerPCB {
        -GroundPlanes
        -SignalLayers
        +ViaFences
        +ResonantSlots
        +ShortedMicrostripStubs
    }
    class PrimaryRFModule {
        +FlightControlDataLinkAntenna
    }
    class SecondaryRFModule {
        +CabinWiFiSlotAntenna
    }
    AvionicsControlUnit --* PrimaryRFModule
    AvionicsControlUnit --* SecondaryRFModule
    AvionicsControlUnit --* MultiLayerPCB
    PrimaryRFModule --> MultiLayerPCB
    SecondaryRFModule --> MultiLayerPCB
    MultiLayerPCB ..> ViaFences
    MultiLayerPCB ..> ResonantSlots
    MultiLayerPCB ..> ShortedMicrostripStubs
    ViaFences --> EMI_Hardening(EMI Hardening)
    ResonantSlots --> EMI_Hardening
    ShortedMicrostripStubs --> EMI_Hardening

Derivative 20.6: Smart Grid Metering Unit with Power-Line Communication (PLC) Isolation

• Enabling Description: A smart grid metering unit includes a cellular antenna (first antenna, e.g., LTE-M for backhaul) and a low-frequency power-line communication (PLC) modem with an associated coupling antenna (second antenna, e.g., a slot formed by the PLC's inductive coupling structure into a conductive casing). Due to the high-current transients and noise on the power lines, isolating the cellular antenna from the PLC coupling structure on the meter's PCB is challenging. The PCB geometry is modified by routing a ground plane "moat" (a U-shaped slot or series of interconnected slots) around the cellular antenna's ground reference and extending towards the PLC section. This moat is designed to be resonant at key interference frequencies generated by the PLC, presenting a high impedance barrier to prevent noise currents from the PLC path from migrating to the cellular antenna's ground, thus enhancing isolation and signal quality for cellular communication.

flowchart TD
    A[Smart Grid Metering Unit] --> B(Cellular Antenna (First))
    A --> C(PLC Coupling Antenna (Second))
    A --> D(Meter PCB)
    D -- Includes --> E(Ground Plane)
    E -- Modify Geometry --> F(Ground Plane Moat / Resonant Slots)
    F -- Placed Between --> B & C
    F -- Tuned to --> G(PLC Interference Frequencies)
    G --> H(High Impedance Barrier)
    H --> I(Enhanced Isolation for Cellular)

---

4. Integration with Emerging Tech

Derivative 20.7: AI-Driven Generative Design for Optimal PCB Isolation Topology

• Enabling Description: A method leveraging AI for automated PCB design in future handheld devices. Instead of manually specifying slots or strips, a generative adversarial network (GAN) or reinforcement learning (RL) agent is trained on a vast dataset of antenna coupling simulations and measured isolation performance. Given the positions and operating bands of the first and second antennas, the AI algorithm automatically generates an optimal ground plane topology for the PCB, including complex, non-intuitive patterns of slots, metamaterial elements, and via fences. The AI iteratively designs and simulates various PCB geometries, optimizing for maximum isolation across specified frequency bands while adhering to manufacturing constraints. This approach can discover novel isolation structures that are superior to human-designed counterparts, moving beyond simple slots to highly optimized, fractal-like or organic patterns specifically tailored for the electromagnetic environment of the device.

sequenceDiagram
    participant Designer as Human Designer
    participant AIGenerator as AI Generative Design Engine
    participant EM_Simulator as EM Simulator
    participant PCB_Fab as PCB Fabrication
    Designer->AIGenerator: Input: Antenna Specs, Positions, Isolation Goals, Constraints
    loop Iterative Design & Optimization
        AIGenerator->AIGenerator: Generate Candidate PCB Ground Plane Topology (slots, metamaterials)
        AIGenerator->EM_Simulator: Simulate Coupling & Isolation
        EM_Simulator->AIGenerator: Feedback: Isolation Performance
        AIGenerator->AIGenerator: Refine Topology (GAN/RL)
    end
    AIGenerator->Designer: Output: Optimized PCB Geometry (CAD Files)
    Designer->PCB_Fab: Fabricate PCB
    PCB_Fab->HandheldDevice: Integrate into Handheld Device

Derivative 20.8: Additive Manufacturing of Smart PCBs with Embedded, Tunable Isolation Features

• Enabling Description: A method using multi-material additive manufacturing (3D printing of electronics) to create smart PCBs for handheld devices. The PCB geometry is modified by directly printing embedded, active isolation features within the dielectric layers. These features could be miniature tunable resonant slots formed by liquid metal encapsulated within printed channels, or shorted conductive strips made of conductive inks whose electrical length can be altered post-fabrication by laser trimming or UV curing. IoT sensors (e.g., tiny EMF probes) are co-printed into the PCB, monitoring real-time coupling. An integrated microcontroller, responding to sensor data, uses precise localized laser trimming (e.g., to adjust slot length) or micro-actuators (to reconfigure liquid metal) to dynamically tune these embedded features. This allows for post-manufacturing calibration and adaptive, self-healing isolation, where PCB features can be modified in situ to compensate for manufacturing tolerances or environmental changes affecting isolation.

flowchart TD
    A[Multi-Material 3D Printer] --> B(Print PCB Layers)
    B --> C(Print Embedded Tunable Slots/Strips - e.g., Liquid Metal)
    B --> D(Co-Print IoT EMF Sensors)
    C -- Control --> E(Tuning Mechanisms - e.g., Laser, Micro-Actuators)
    D -- Real-time Data --> F(On-board Microcontroller)
    F -- Monitor Coupling --> G{Isolation Optimal?}
    G -- No --> F
    F -- Send Command --> E
    E --> C(Tune Embedded Isolation Features)
    G -- Yes --> H(Maintain Isolation)

---

Derivative Variations for Independent Claim 23: Handheld Device with Parasitic Element for Isolation

Core Claim 23: A handheld device comprising a first antenna for at least one mobile communication service, a second antenna being a slot antenna for at least one wireless connectivity service, and a conducting strip placed in the vicinity of the first antenna and the second antenna, wherein said conducting strip is not connected to the ground plane of the PCB of the handheld device, and wherein an unfolded length of the conducting strip is approximately half of an operating wavelength at a frequency for which the isolation between the first antenna and the second antenna is to be enhanced, and wherein said conducting strip functions as a shield for electromagnetic radiation between the first antenna and the second antenna.

---

1. Material & Component Substitution

Derivative 23.1: Metamaterial-Based Resonant Parasitic Shield

• Enabling Description: The handheld device incorporates a first antenna (e.g., a cellular IFA) and a second slot antenna (e.g., WLAN). Instead of a simple conducting strip, a two-dimensional metamaterial array, composed of sub-wavelength resonant elements (e.g., an array of split-ring resonators or patch elements), is placed in the vicinity of the two antennas. This metamaterial structure is printed on a thin dielectric substrate (e.g., Kapton film) and is not connected to the PCB ground plane. The unit cells of the metamaterial array are designed to resonate collectively at the specific frequency where isolation needs enhancement (e.g., a troublesome harmonic of the cellular antenna that couples to the WLAN band). This metamaterial acts as a highly frequency-selective electromagnetic shield, reflecting or absorbing incident waves at the target frequency, providing superior shielding performance compared to a simple conducting strip, especially in terms of bandwidth or tunability. Its unfolded electrical length is effectively a half-wavelength at the desired isolation frequency, achieved through slow-wave propagation within the metamaterial.

componentDiagram
    [Handheld Device] --> [First Antenna (Cellular IFA)]
    [Handheld Device] --> [Second Antenna (WLAN Slot)]
    [Handheld Device] --> [PCB]
    [PCB] .. Adjacent ..> [Metamaterial Array (Parasitic Shield)]
    [Metamaterial Array (Parasitic Shield)] .. Not Connected ..> [PCB]
    [Metamaterial Array (Parasitic Shield)] -- Resonates @ Coupling Freq --> [Frequency Selective Shielding]
    [Frequency Selective Shielding] --> [Enhanced Isolation]

Derivative 23.2: Dielectric Resonator Parasitic Element for Tunable Isolation

• Enabling Description: A handheld device features a first antenna (e.g., a UWB antenna) and a second slot antenna (e.g., a GPS L1 band slot antenna). A dielectric resonator (DR) of specific dimensions and high dielectric constant material (e.g., ceramic like BaTiO3 or ZrTiO4) is positioned as a parasitic element between the two antennas. This DR is not electrically connected to the PCB ground plane. The DR's physical dimensions and material properties are chosen such that it exhibits a strong electromagnetic resonance (e.g., TE01δ mode) at the GPS L1 frequency. When excited by fields from the UWB antenna, the DR acts as a resonant "scatterer" or filter, effectively creating a local electromagnetic null or phase shift that disrupts the coupling path between the UWB antenna and the GPS slot antenna. The resonant frequency of the DR can be finely tuned by adjusting its physical dimensions or by integrating varactors into its structure, providing a reconfigurable shield. The effective electrical length of the DR's resonant mode is approximately half a wavelength at the target frequency.

graph TD
    A[Handheld Device] --> B(UWB Antenna (First))
    A --> C(GPS Slot Antenna (Second))
    B -- Fields --> D(Dielectric Resonator (Parasitic))
    D -- Not Connected --> E(PCB Ground Plane)
    D -- Resonates @ GPS L1 Freq --> F(Electromagnetic Null / Phase Shift)
    F --> G(Disrupts Coupling Path)
    G --> H(Enhanced Isolation)

---

2. Operational Parameter Expansion

Derivative 23.3: Tunable Liquid Crystal Polymer (LCP) Parasitic Sheet for mmWave Handhelds

• Enabling Description: In a mmWave handheld device (e.g., 5G mobile), a first antenna (e.g., a 28 GHz patch array) and a second antenna (e.g., a 39 GHz slot array) are co-located. A thin sheet of Liquid Crystal Polymer (LCP) with embedded, non-connected conductive traces is placed as a parasitic element between the arrays. The LCP's dielectric properties can be tuned by applying an external DC bias voltage. The conductive traces on the LCP are designed to form a half-wavelength resonant structure at a specific mmWave frequency when the LCP is in a particular dielectric state. By adjusting the bias voltage, the effective electrical length and resonant frequency of the parasitic element can be dynamically shifted. This allows for real-time adaptation of the parasitic shield to optimize isolation for varying mmWave bands or to suppress dynamic interference, functioning as an agile frequency-selective electromagnetic shield.

stateDiagram
    state "Initial Isolation State" as Initial
    state "Interference Detected" as Interference
    state "Isolation Re-tuned" as ReTuned

    Initial --> Interference: Coupling Exceeds Threshold
    Interference --> ReTuned: Apply DC Bias to LCP
    ReTuned --> Initial: Isolation Optimized

    state "LCP Control" {
        Interference --> "Vary DC Bias" as Bias
        Bias --> "Tune LCP Dielectric Constant" as TuneDielectric
        TuneDielectric --> "Shift Parasitic Element Resonance" as ShiftResonance
        ShiftResonance --> ReTuned
    }
    ReTuned: Tunable LCP Parasitic Shield
    ReTuned: Half-Wavelength Resonance
    ReTuned: Dynamic Isolation

Derivative 23.4: Reconfigurable Metasurface Parasitic Element for Wideband Isolation

• Enabling Description: A handheld device integrates a wideband primary cellular antenna (e.g., 600 MHz - 6 GHz) and a secondary ultra-wideband (UWB) slot antenna (e.g., 3.1 - 10.6 GHz). To enhance isolation across multiple potentially interfering bands, a reconfigurable metasurface is employed as a parasitic element. This metasurface consists of an array of electronically tunable meta-atoms (e.g., varactor-loaded unit cells, MEMS-tunable elements) printed on a flexible substrate, placed near the antennas but not connected to the PCB ground. The metasurface is programmed to exhibit a half-wavelength effective resonance at multiple distinct frequencies simultaneously or to adapt its resonant response dynamically across a broad spectrum. An intelligent controller adjusts the tuning state of the meta-atoms to create a "smart shield" that selectively blocks or reflects unwanted radiation from the primary antenna into the UWB slot antenna at specific problematic frequencies or bands (e.g., 2.4 GHz Wi-Fi harmonics, 5 GHz cellular carrier leakage).

classDiagram
    class HandheldDevice {
        +FirstAntenna: Wideband Cellular
        +SecondAntenna: UWB Slot
        +Controller
    }
    class ReconfigurableMetasurface {
        -TunableMetaAtoms
        -VaractorLoads
        -MEMSTuners
        +programResonance(freqs)
    }
    class Controller {
        +monitorSpectrum()
        +programMetasurface(targetFreqs)
    }
    HandheldDevice --* ReconfigurableMetasurface
    HandheldDevice --* Controller
    Controller --> ReconfigurableMetasurface: calls programResonance()
    ReconfigurableMetasurface <--> TunableMetaAtoms

---

3. Cross-Domain Application

Derivative 23.5: Multi-Channel MRI Coil with Resonant Parasitic Decoupling Rings

• Enabling Description: In a multi-channel Magnetic Resonance Imaging (MRI) receive coil array (e.g., for brain imaging), each coil acts as a "first antenna" (transmitting/receiving RF signals at the Larmor frequency, typically 1.5T or 3T, ~64MHz or ~128MHz). A co-located implantable sensor or diagnostic device inside the patient, with its own small antenna (second antenna, e.g., for local temperature sensing via RF), experiences coupling from the strong MRI RF fields. To enhance isolation between adjacent MRI coils and from the MRI coils to the implantable antenna, a non-connected resonant parasitic element is introduced. This element takes the form of precisely dimensioned conductive "decoupling rings" or "floating shields" placed between adjacent MRI coils or between the coil and the implant. These rings are designed to have an unfolded length of approximately half a wavelength at the Larmor frequency. They function as resonant current loops that absorb or reradiate energy out of phase, effectively reducing mutual inductance between coils and shielding the implantable antenna from unwanted strong RF fields, preventing signal distortion and ensuring patient safety.

flowchart TD
    A[MRI Receive Coil Array] --> B(MRI Coil 1 (First Ant))
    A --> C(MRI Coil 2 (First Ant))
    A --> D(Implantable Sensor (Second Ant))
    B -- Located Near --> C
    B -- Located Near --> D
    B -- Introduce --> E(Resonant Decoupling Ring (Parasitic))
    C -- Introduce --> F(Resonant Decoupling Ring (Parasitic))
    E -- Not Connected --> G(Ground Plane / Shielding)
    F -- Not Connected --> G
    E & F -- Resonates @ Larmor Freq --> H(Absorb/Reradiate Out of Phase)
    H --> I(Reduced Mutual Inductance / Shielding)
    I --> J(Enhanced Isolation & Signal Integrity)

Derivative 23.6: Maritime Buoy Communication System with Environmental Adaptive Shields

• Enabling Description: A maritime data buoy deploys a primary long-range satellite communication antenna (first antenna, e.g., Iridium/Inmarsat L-band) and a secondary short-range local data offload antenna (second antenna, e.g., Wi-Fi slot antenna, 2.4 GHz). Due to the harsh and dynamic marine environment (e.g., saltwater splash, changing water levels, buoy tilt), coupling between the antennas can vary significantly. To enhance isolation, a flexible, non-connected parasitic element is deployed. This element is a conductive fabric strip (e.g., silver-coated nylon) integrated into a retractable or deployable mechanism on the buoy's structure. The fabric strip is designed to have an unfolded length of approximately half a wavelength at the 2.4 GHz Wi-Fi band. Environmental sensors (e.g., accelerometers for tilt, conductivity sensors for water proximity) trigger the deployment or retraction of the fabric strip. When high coupling is detected (e.g., due to specific buoy orientation or water ingress), the strip is moved into an optimal position between the antennas, physically shielding and resonantly decoupling them, thereby restoring isolation.

sequenceDiagram
    participant Buoy as Maritime Buoy
    participant SatAnt as Satellite Antenna (First)
    participant WiFiSlotAnt as Wi-Fi Slot Antenna (Second)
    participant EnvSensors as Environmental Sensors
    participant Controller as Buoy Controller
    participant FlexParasitic as Flexible Parasitic Strip
    EnvSensors->Controller: Report Tilt/Water Level
    Controller->Controller: Assess Coupling Risk
    alt High Coupling Risk
        Controller->FlexParasitic: Deploy/Retract to Optimal Position
        FlexParasitic->SatAnt: Shields Electromagnetic Radiation
        FlexParasitic->WiFiSlotAnt: Shields Electromagnetic Radiation
        FlexParasitic->FlexParasitic: Half-Wavelength Resonance
        SatAnt->WiFiSlotAnt: Enhanced Isolation
    else Low Coupling Risk
        Controller->Controller: Maintain Current State
    end

---

4. Integration with Emerging Tech

Derivative 23.7: AI-Optimized Active Parasitic Element for Smart Surface Devices

• Enabling Description: A "smart surface" handheld device (e.g., a large-format flexible display or a tabletop computing device) incorporates embedded cellular antennas (first antennas) and an array of local Wi-Fi slot antennas (second antennas). A flexible, non-connected parasitic element is formed by an array of active metamaterial unit cells, each containing a varactor or MEMS switch, embedded just beneath the smart surface. An AI-driven controller, processing real-time channel state information from all antennas, continuously optimizes the impedance and phase response of each unit cell in the parasitic array. The AI algorithm determines the optimal "virtual shape" and resonant frequency of the parasitic array (effectively creating multiple dynamically tunable half-wavelength resonant regions) to create a reconfigurable electromagnetic shield. This shield adaptively suppresses unwanted coupling between specific cellular and Wi-Fi antenna pairs, even as the smart surface deforms or user interaction changes the electromagnetic environment.

graph TD
    A[Smart Surface Device] --> B(Flexible Display/Substrate)
    B --> C(Embedded Cellular Antennas (First))
    B --> D(Wi-Fi Slot Antenna Array (Second))
    B --> E(Active Metamaterial Parasitic Array)
    E -- Varactors/MEMS --> F(Tunable Unit Cells)
    F -- Control Signals --> G(AI Controller)
    G -- Real-time CSI --> H(Antenna Coupling Monitor)
    H --> I(Optimal Metasurface Configuration)
    I --> F
    F --> J(Adaptive Electromagnetic Shield)
    J --> K(Enhanced Isolation)

Derivative 23.8: Self-Healing Parasitic Element via Conductive Polymer 3D Printing and Repair Bots

• Enabling Description: A ruggedized handheld device (e.g., for industrial field use) features a first antenna (e.g., a robust external whip antenna for L-band satellite) and an internal Wi-Fi slot antenna. A non-connected parasitic element, a conductive polymer strip, is 3D printed directly onto a sacrificial layer within the device casing, acting as an electromagnetic shield with an unfolded half-wavelength. In the event of physical damage to the device (e.g., impact causing a crack in the casing), the conductive polymer parasitic element might be compromised, degrading its resonant behavior and thus isolation. The device incorporates miniature, autonomous "repair bots" (e.g., micro-drones or robotic arms) that, upon detecting a fault in the parasitic element (e.g., via electrical resistance monitoring), deploy a small amount of repair-grade conductive polymer. These bots use embedded sensors and 3D printing capabilities to mend the damaged parasitic strip, restoring its original electrical length and resonant shielding properties, thereby maintaining enhanced isolation.

flowchart TD
    A[Rugged Handheld Device] --> B(First Antenna (External))
    A --> C(Second Antenna (Internal Slot))
    A --> D(3D Printed Conductive Polymer Parasitic)
    D -- Monitoring --> E(Fault Detection System)
    E -- If Fault Detected --> F(Deploy Repair Bots)
    F --> G(Repair Damaged Parasitic Element)
    G --> H(Restore Half-Wavelength Resonance)
    H --> I(Maintain Enhanced Isolation)

---

Combination Prior Art Scenarios

Here are three scenarios where US patent 8,362,960 (or its derivative concepts) could be combined with existing open-source standards to create prior art, rendering subsequent incremental improvements obvious.

1. US8362960 (Claim 1) + IEEE 802.11ay (Wi-Fi 7 / mmWave Standard)

• Scenario: A handheld device (smartphone, tablet) implementing the features of US8362960, specifically a first antenna for cellular communication (e.g., LTE/5G sub-6 GHz) and a second antenna being a slot antenna for high-speed local connectivity. The improvement here is that the "second antenna" is implemented as a multi-antenna array operating under the IEEE 802.11ay standard (Wi-Fi 7), specifically for mmWave frequencies (e.g., 60 GHz).
• Combination:
  • US8362960 teaches the use of a slot antenna as the second antenna, and its orientation parallel to the ground plane currents of the first antenna to enhance isolation.
  • IEEE 802.11ay defines the physical layer (PHY) and media access control (MAC) for very high throughput (VHT) operation in the 60 GHz band, including multi-antenna techniques (MIMO, beamforming). Implementing a mmWave Wi-Fi 7 antenna as a slot antenna (or an array of slot antennas) is a known design choice for planar integration in compact devices.
• Obviousness Argument: A PHOSITA would find it obvious to apply the isolation principles of US8362960 to a modern handheld device incorporating a cellular antenna and a mmWave Wi-Fi 7 antenna. Given the need for high isolation between cellular and mmWave components, and the advantages of slot antennas for miniaturization and integration (as described in US8362960), it would be an obvious design choice to implement the Wi-Fi 7 antenna as a slot antenna array and orient it to minimize coupling with the cellular antenna's induced ground currents. The specific techniques for slot antenna design at mmWave frequencies are well-known in the art (e.g., substrate integrated waveguide (SIW) slots, microstrip-fed slots).

2. US8362960 (Claim 15) + Open-Source Cognitive Radio Framework (e.g., GNU Radio)

• Scenario: A software-defined radio (SDR) based handheld device (e.g., a portable spectrum analyzer or research platform) utilizes a first reconfigurable antenna and a second fixed-frequency slot antenna. The device employs an open-source cognitive radio framework (like GNU Radio) to dynamically manage spectrum.
• Combination:
  • US8362960 (Claim 15) teaches a method of modifying a geometrical feature of the first antenna (electrically longer/shorter) to shift its resonance frequency away from the operating band of the second antenna to reduce coupling.
  • Open-source cognitive radio frameworks (e.g., GNU Radio) provide software modules and hardware interfaces for real-time spectrum sensing, interference detection, and adaptive radio parameter adjustments.
• Obviousness Argument: A PHOSITA, building a cognitive radio handheld device using GNU Radio, would foresee scenarios where dynamic antenna tuning is necessary to avoid self-interference. Knowing from US8362960 that modifying antenna geometry can shift resonances and improve isolation, it would be obvious to integrate this principle into the cognitive radio system. The GNU Radio framework could be used to: (a) monitor coupling levels and spectrum occupancy, (b) identify problematic resonances of the first antenna, and (c) issue control signals (e.g., to MEMS switches, varactor diodes, or even mechanical actuators on a reconfigurable antenna) to modify a geometrical feature of the first antenna, shifting its resonance away from the second antenna's operating band, all orchestrated by the open-source software logic.

3. US8362960 (Claim 20) + Open Compute Project (OCP) PCB Design Guidelines

• Scenario: A handheld server-on-a-chip or a high-density compute module adhering to Open Compute Project (OCP) design principles for compact, efficient hardware. This module contains multiple wireless communication antennas (e.g., a primary mesh network antenna and a secondary short-range management slot antenna).
• Combination:
  • US8362960 (Claim 20) describes a method of modifying PCB geometry (slots, conductive strips) to introduce features that increase isolation between antennas.
  • The Open Compute Project (OCP) provides open-source hardware designs and specifications, including guidelines for high-density, low-EMI PCB layouts in server and data center environments. These guidelines often discuss optimal ground plane design and noise mitigation.
• Obviousness Argument: A PHOSITA designing an OCP-compliant handheld compute module with multiple integrated wireless antennas would be acutely aware of the need for robust EMI and isolation management within the densely packed PCB. Given OCP's emphasis on open standards and efficient design, and knowing from US8362960 that modifying PCB geometry (like adding slots or shorted strips) enhances isolation, it would be an obvious and desirable step to incorporate such features into the OCP PCB design. The specific dimensions and placement of these isolation features would be determined through standard RF simulation tools, aiming to align with the OCP principles of efficiency and reliability. The problem (inter-antenna coupling in a compact, multi-radio PCB) and the solution (PCB ground plane modification) are directly taught by US8362960, and applying this to an OCP hardware design would be a straightforward engineering task.