US 6408193

I'll run targeted searches for this patent number and its current litigation status.

Let me check the Federal Circuit appeal history and any 2026 activity for this patent.

One more check on whether the '193 patent itself is in any pending 2026 appeal.

US 6,408,193 B1 — Analyst Summary

Source of record: US patent text fetched from Google Patents (patents.google.com/patent/US6408193B1/en); cross-checked against Unified Patents portal and RPX/Docket Alarm PTAB records.

1. Bibliographic data

2. Abstract (verbatim)

A cellular telephone receives a first communication signal from a cell-site station and transmits a second communication signal to the cell-site station. The cellular telephone includes an antenna, a duplexer, a receiver, an encoder/decoder apparatus, an acoustic transducer, a transmitter and a controller. The receiver is connected to the antenna through the duplexer. The receiver converts the first communication signal into a voice signal code, and outputs a signal indicating an intensity of the first communication signal. The transmitter is connected to the encoder/decoder apparatus and to the antenna through the duplexer. The receiver converts the input voice code signal from the encoder/decoder apparatus into the second communication signal. The controller is connected to the receiver and the transmitter. The controller controls amplitude of the transmitter corresponding to said intensity of the first communication signal. The transmitter includes a variable amplitude amplifier and a power amplifier means, and the controller includes a central processing unit and a memory. The controller controls a gain of the variable amplitude amplifier and a bias condition of the power amplifier means according to a function stored in the memory.

3. Independent claims in plain language

The patent has 7 claims; only claims 1 and 7 are independent (claims 2–5 depend from claim 1, claim 6 depends from claim 1).

Claim 1 — Coordinated gain + bias control under open‑loop-then‑closed‑loop power control

A CDMA cellular telephone in which:

• the antenna receives both a first communication signal and a transmit‑power control signal from the cell site, and transmits a second communication signal back;
• the receiver converts the received signal into a voice code and outputs a power control signal derived from the cell‑site's transmit‑power control signal;
• an encoder/decoder plus acoustic transducer (speaker/mic) handle voice in both directions;
• the transmitter contains a variable amplitude amplifier and a power amplifier;
• the controller (CPU + memory) runs power control in two phases — open‑loop control first, then closed‑loop control based on the cell‑site power control signal — to make transmit power converge to the range the cell site requires; and
• the controller sets the gain of the variable amplitude amplifier and the bias condition of the power amplifier using a set of bias‑and‑gain data stored in the memory (rather than a single fixed bias).

Practical effect: the power amplifier's bias is stepped down together with gain as required output power falls, so current draw (and battery drain) drops at low/medium output levels while maximum power capability is still met.

Claim 7 — Gain control by stored function, with maximum‑power detection

Same preamble as claim 1 (CDMA phone; antenna receives the signal and the transmit‑power control signal; duplexer; receiver outputting a power control signal derived from the cell‑site's transmit‑power control signal; encoder/decoder + transducer; transmitter with variable amplitude amplifier and power amplifier), but:

• the power amplifier includes a maximum‑power detector;
• the controller performs open‑loop then closed‑loop power control to converge transmit power to the cell‑site's required range;
• the controller controls only the gain of the variable amplitude amplifier, using a function defining a relation between bias data and gain data stored in memory; and
• the maximum‑power detector controls the output power of the power amplifier (i.e., output limiting is delegated to the detector, and the controller no longer sends a bias control signal to the PA).

Dependent claims (brief)

• Claim 2: controller includes a pulse generator feeding pulses to the power amplifier as the bias control signal; pulse width (PWM) sets the bias condition.
• Claim 3: power amplifier further includes a smoothing circuit to smooth the pulse.
• Claim 4: as claim 2 but pulse density (PDM) sets the bias condition.
• Claim 5: as claim 4, plus a smoothing circuit.
• Claim 6: transmitter further includes a signal generator connected to the controller and to both the variable amplitude amplifier and power amplifier, supplying their gain and bias control signals respectively.

⚠️ Note on claim vs. specification wording: the specification/abstract describe the receiver output as "a signal indicating an intensity of the first communication signal," whereas issued claims 1 and 7 recite a "power control signal derived from said transmitting power control signal sent from said cell‑site station." The claims thus capture the closed‑loop CDMA aspect more explicitly than the abstract does.

4. Litigation / PTAB posture (as found)

• PTAB IPR2020‑00203 — Apple Inc. v. Maxell, Ltd. (IPR of US6408193B1), filed 2019‑12‑20; institution denied 2020‑07‑06 on Fintiv-style discretionary grounds.
• PTAB IPR2018‑00237 — filed by ZTE; not instituted (merits).
• Maxell v. ZTE, E.D. Tex. 5:16‑cv‑00179 — the '193 patent was one of the patents in the case that produced a reported ~$43.3M verdict for Maxell across seven patents; the '193 patent survived the IPR challenge.
• Maxell v. Apple, E.D. Tex. 5:19‑cv‑00036 — '193 patent asserted (claims 1, 6, 7 per Apple's invalidity contentions); case settled March 2021 and dismissed with prejudice 2021‑04‑07.
• CAFC 20‑2132 — Apple's appeal from the PTAB's refusals to institute (including IPR2020‑00203); the appeal was dismissed for lack of jurisdiction under 35 U.S.C. § 314(d), with a combined petition for panel/en banc rehearing and an intervenor's response (Feb. 2021).

5. Explicit uncertainties / limits of this search

1. No pending 2026 CAFC docket tied to US 6,408,193 was found. The 2026 Federal Circuit activity I located is Maxell v. Samsung Electronics (Nos. 26‑1111, 26‑1320, 26‑1330, 26‑1623, 26‑1625) and concerns other Maxell patents (personal‑electronics/video‑processing and related PTAB appeals). I did not find authority confirming the '193 patent is at issue in any 2026 appeal, and the patent itself is expired (2019‑11‑09), making new infringement assertion unlikely.
2. Date discrepancies exist across databases (priority 1998‑11‑10 vs. 1998‑10‑11; filing 1999‑11‑08 vs. 1999‑11‑09; issue 2002‑06‑17 vs. 2002‑06‑18). I have reported them literally rather than reconciling them.
3. I did not directly query PACER/PatentCenter in real time; the USPTO‑sourced facts here rest on the Google Patents legal‑events table, the Unified Patents portal, and RPX/Docket Alarm records retrieved in search.
4. The claim‑level details above are taken from the authoritative full patent text supplied; where search results differed in wording, I deferred to the patent text.

I'll research litigation involving US patent 6408193 using targeted searches.

Let me dig deeper into the specific cases, the CAFC appeal, and the PTAB/reexam proceedings.

Let me pin down the PTAB IPR outcomes and the ex parte reexamination.

Litigation and Related Proceedings for US Patent 6,408,193 ("Cellular Telephone")

Bottom line: Yes — substantial litigation is known for US 6,408,193 (the "'193 patent"), all involving Maxell, Ltd. (formerly Hitachi Maxell / Hitachi) as patent owner, and all arising in the Eastern District of Texas, the PTAB, and the Federal Circuit. There is no active litigation today; the patent expired via anticipated expiration on 2019‑11‑09, and the last case/appeal concluded in 2021.

Important framing note: You asked specifically for patent 6408193. I have excluded cases that involved only Maxell's other patents (e.g., the '443, '794, '317, '493, '729, '491, '695 patents).

1. District Court Litigation

A. Maxell, Ltd. v. ZTE Corporation and ZTE (USA) Inc.

• Court/Jurisdiction: U.S. District Court for the Eastern District of Texas, Texarkana Division (Judge Robert W. Schroeder, III)
• Case No.: 5:16-cv-00179-RWS
• Filed: November 18, 2016 (docket reflects Nov. 17, 2016)
• Plaintiff: Maxell, Ltd. Defendants: ZTE Corporation; ZTE (USA) Inc.
• '193 patent role: Asserted against ZTE USA, one of eight patents initially asserted (U.S. Patent Nos. 5,396,443; 6,748,317; 8,339,493; 8,736,729; 6,408,193; 6,329,794; 6,816,491; 8,098,695).
• Outcome: Jury verdict June 29, 2018 finding ZTE willfully infringed seven patents; the jury found at least claim 1 of the '193 patent was willfully infringed (accused product: ZMax 2). Damages: $43.3 million (reported ~$43.3M / RMB 289M). Post‑trial motions (Rule 50/59) followed.
• Current status: Settled and dismissed. Parties filed a notice of settlement and motion to stay (Feb. 2019); the court entered an Order of Dismissal with prejudice (March 12, 2019) and a Final Judgment, terminating on March 11/12, 2019. (E.D. Tex. docket 5:16-cv-00179)

B. Maxell, Ltd. v. Apple Inc.

• Court/Jurisdiction: U.S. District Court for the Eastern District of Texas, Texarkana Division (Judge Robert W. Schroeder, III)
• Case No.: 5:19-cv-00036-RWS
• Filed: March 15, 2019 (amended complaint October 2019)
• Plaintiff: Maxell, Ltd. Defendant: Apple Inc.
• '193 patent role: Included among the asserted patents (originally 10 patents; Maxell was later ordered to narrow to six). The '193 patent ("Cellular telephone") appears in the case's patent list.
• Outcome: Settled on the eve of trial. The parties reached a settlement on the day of jury selection (March 2021); an accompanying PTAB proceeding was called off. The court granted the joint motion to dismiss and entered Final Judgment dismissing the case with prejudice on April 7, 2021. Terms undisclosed. (CourtListener docket 5:19-cv-00036; UniCourt summary)

C. Consolidated pretrial: Maxell, Ltd. v. [Huawei Device USA Inc.](/litigations/by-defendant/Huawei%20Device%20USA%20Inc.) (related, but '193 NOT asserted here)

• Case No.: 5:16-cv-00178 (Huawei), consolidated with 5:16-cv-00179 (ZTE) for pretrial purposes.
• Note: The '193 patent was asserted only against ZTE USA, not Huawei. The consolidated claim‑construction order (Maxell Ltd. v. Huawei Device U.S. Inc., 297 F. Supp. 3d 668 (E.D. Tex. 2018)) lists the '193 patent among the patents asserted against ZTE USA, and it construed the "bias" terms of '193 claims 1 and 7. I flag this because it is a separate case number but is part of the same litigation family and an important source of claim construction for the '193 patent.

2. PTAB — Inter Partes Review

A. Apple Inc. v. Maxell, Ltd., IPR2020-00203 (U.S. Pat. 6,408,193)

• Filed: December 20, 2019
• Petitioner: Apple Inc. Patent Owner: Maxell, Ltd.
• Challenged claims: 1, 6, and 7, under 35 U.S.C. §103(a) over Waldroup in view of Nakayama.
• Outcome: Institution DENIED (procedural) — the Board exercised discretion under §314(a) (NHK‑Fintiv factors) in view of the advanced parallel E.D. Tex. litigation; Apple's request for a stay had been denied. (Docket Alarm IPR2020-00203)
• Current status: Not instituted; no final written decision. Note: the patent‑page "Family has litigation" entry labels this "Not Instituted – Procedural," consistent with the Fintiv‑based denial.

B. ZTE Corporation v. Maxell, IPR2018-00237

• Filed: November 22, 2017 (Google Patents lists effective date Nov. 22, 2017)
• Petitioner: ZTE Corporation and ZTE (USA) Inc. Patent Owner: Maxell, Ltd.
• Outcome: Not instituted (Merits). One of seven IPR petitions ZTE filed against Maxell's asserted patents; PTAB denied the last of them in July 2018. The asserted patents "each survived IPR petitions filed by ZTE."
• Current status: Not instituted. (Google Patents US6408193 litigation listing)

3. Federal Circuit Appeal

Apple Inc. v. Maxell, Ltd., Nos. 2020-2132, -2211, -2212, -2213, and 2021-1033

• Court: U.S. Court of Appeals for the Federal Circuit
• Filed: August 6, 2020 (lead No. 20-2132); consolidated with 20-2211, -2212, -2213, and 21-1033
• Parties: Apple Inc. (Appellant) v. Maxell, Ltd. (Appellee); USPTO Director intervened
• Relationship to '193: Appeal from the PTAB's denial of institution in IPR2020-00203 (the '193 patent) together with IPR2020-00407, -00408, -00409, and -00597 (other Maxell patents).
• Outcome: Dismissed for lack of jurisdiction — the panel (Judges Dyk, Wallach, Taranto) held the court lacks jurisdiction over appeals from non‑institution decisions (35 U.S.C. §314(d)). Apple's combined petition for panel rehearing and rehearing en banc was denied February 22, 2021; mandate issued March 1, 2021. (Fed. Cir. order)
• Current status: Concluded.

4. Related USPTO Administrative Proceeding (not litigation, but relevant to the '193 patent)

• Ex parte reexamination of U.S. Pat. 6,408,193 — a third‑party request for reexamination was filed December 18, 2020; a Reexamination Certificate issued November 2, 2021 (effective October 29, 2021), confirming the claims ("Reexamination decision confirms claims"). (Google Patents legal events)
• ⚠️ Caveat: I was not able to confirm the exact reexamination control number assigned to the '193 patent from the sources retrieved. I did not locate a reliable control number, so I am not supplying one rather than guessing. The similar 90/014,651 number that appeared in search results belongs to a different Maxell patent (U.S. 10,129,590), not the '193 patent.

5. Items I could not confirm

• ITC Investigation 337-TA-1215 (Maxell v. Apple, instituted Aug. 19, 2020): This ITC action involved Maxell's later patents (e.g., U.S. 10,129,590 and related display/video patents), not the '193 patent. I did not find evidence that the '193 patent was asserted in the ITC. I flag it so you do not mistakenly attribute it to the '193 patent.
• W.D. Tex. case 6:20-cv-00646 (Maxell v. Apple, 2020): Also appears related to Maxell's newer patents ('821, '590), not the '193 patent.
• I did not find any litigation involving the '193 patent outside the U.S. (e.g., no foreign infringement suits reported for the '193 patent family). ZTE's parallel invalidation attempts occurred in China's CNIPA/Patent Reexamination Board, but those targeted the camera‑related Maxell patents (Chinese Patent Nos. 200710196177.3 and 02815547.5), not the '193 patent. So, strictly for US 6,408,193, the litigation is limited to the U.S. proceedings above.

Summary Table

Primary sources: Google Patents US6408193; Unified Patents litigation portal 5:16-cv-00179; Docket Alarm IPR2020-00203; CourtListener 5:19-cv-00036; Fed. Cir. rehearing order; Docket Alarm 5:16-cv-00179 docket.

I'll verify the PTAB record for this patent, since the structured block says "none on file" but the patent's own legal-events table lists two IPRs and a reexamination.

Now let me pin down the IPR2018-00237 denial details, the IPR2020-00203 panel, and the reexamination outcome.

Let me confirm the IPR2018-00237 denial date/grounds and the reexamination control number for the '193 patent.

⚠️ Contradiction flagged up front

The structured "PTAB proceedings on file" block in this prompt states the USPTO ODP API returns no AIA trial proceedings for US 6,408,193. That is inconsistent with the record, and I am departing from it:

• The patent's own Google Patents legal‑events table (fetched 2026‑09‑28 from patents.google.com/patent/US6408193B1/en) lists two AIA trial proceedings: an "IPR" event for IPR2018‑00237 (effective 2017‑11‑22, opponent "ZTE CORPORATION AND ZTE (USA) INC.") and an "IPR" event for IPR2020‑00203 (effective 2019‑12‑20, opponent "APPLE, INC.").
• Both are independently corroborated by Docket Alarm PTAB dockets and RPX Insight (IPR2020‑00203 docket, IPR2018‑00237 docket, RPX Insight IPR2020‑00203).

My read: the ODP ingest behind the structured block is incomplete/stale for this patent, not that the proceedings are phantom. Proceeding numbers below are taken verbatim from the docket records cited; I did not generate any.

Proceedings overview

Two AIA trial proceedings have been filed against US 6,408,193 — both Inter Partes Reviews, both denied institution, zero Final Written Decisions, and therefore zero canceled claims. Breakdown by status: active: 0 · claims invalidated: 0 · claims sustained: 0 (never reached) · settled: 0 · institution denied: 2 (one discretionary/Fintiv — IPR2020‑00203; one merits — IPR2018‑00237).

Bottom line for a defendant: the opposite of a hardened patent — this is a never‑instituted patent. The PTAB has never issued a single substantive word adopting or rejecting any claim, so no claim of the '193 patent is cancelled, but equally no § 315(e) estoppel attaches to either petitioner. The practical defensive posture is dominated by two other facts: (i) the patent expired 2019‑11‑09, and (ii) the last two attempts to kill it at the Board were disposed of on non‑institution grounds that the Board never had to defend on the merits in either case — meaning a new petitioner gets a clean, unstipulated shot if the patent were still enforceable. The strongest point for a demand‑letter recipient is not the PTAB record at all; it is the expiration date (see Strategic summary).

IPR2020-00203 — Apple Inc. v. Maxell, Ltd.

• Type: Inter Partes Review
• Patent: US 6,408,193 B1
• Filed: 2019-12-20 (Google Patents legal events records effective date 2019-12-20; notice according filing date 2020-01-13)
• Status: Institution Denied (Google Patents: "Not Instituted – Procedural"; PTAB/Docket Alarm: "Institution Denied," institution date 2020‑07‑06)
• Judge panel: Kevin Trock, Lynne Pettigrew, and Minn Chung (Art Unit 2683, Tech Center 2600) — per the Docket Alarm docket.
• Petition grounds: Challenged claims 1, 6, and 7 under 35 U.S.C. § 103(a) over Waldroup and Nakayama, supported by the Declaration of Dr. William Redman‑White (Ex. 1006). (Op‑Below reproduced at fedcircuitblog.com AppleMaxell_OpBelow.pdf.)
• Institution decision: Denied 2020‑07‑06 under 35 U.S.C. § 314(a) on Apple Inc. v. Fintiv, Inc., IPR2020‑00019, Paper 11 (PTAB Mar. 20, 2020) (precedential) grounds. The panel authorized supplemental Fintiv briefing because the parallel E.D. Tex. case (Maxell v. Apple, 5:19‑cv‑00036) was set for trial 2020‑10‑26 — roughly eight months before the projected FWD deadline. Fintiv factor 4 (overlap) was decisive: unlike the companion IPR2020‑00204 (same parties, same litigation, instituted 2020‑06‑19) where Apple offered to drop the primary reference from its district‑court contentions, here Apple offered no such stipulation, so the same Waldroup/Nakayama art was live in both fora. Contemporary commentary: "In this case, however, the petitioner did not promise to eliminate any of the references… Because the same references were being used by the petitioner in both the IPR proceeding and at the District Court, this PTAB panel determined that factor four weighed in favor of denial and on that basis, denied the IPR petition." (PTAB Litigation Blog; Jones Day / Mondaq). Note this was a procedural denial followed by 35 U.S.C. § 315(e)(2) estoppel of Apple — IPR2020‑00203 is not one, because no FWD issued.
• Final Written Decision: None. Trial was never instituted, so no claim was construed, cancelled, or confirmed. Claims 1, 6, and 7 were not adjudicated.
• Settlement / termination: No PTAB settlement — the proceeding simply never started. The parallel district‑court case (Maxell v. Apple, E.D. Tex. 5:19‑cv‑00036) settled and was dismissed with prejudice 2021‑04‑07; the terms are confidential.
• Appeal: Yes. Apple appealed the non‑institution to the Federal Circuit: Apple Inc. v. Maxell, Ltd., No. 2020‑2132 (consolidated with Nos. 2020‑2211, 2020‑2212, 2020‑2213, 2021‑1033, covering IPR2020‑00203, ‑00407, ‑00408, ‑00409, and ‑00597). A panel of Judges Dyk, Wallach, and Taranto dismissed the appeal on 2020‑10‑30 for lack of jurisdiction under 35 U.S.C. § 314(d) (institution decisions are "final and nonappealable"), applying Cuozzo and In re Cisco Systems. Apple's combined petition for panel rehearing and rehearing en banc was denied 2021‑02‑22, with mandate issuing 2021‑03‑01. (Denial order; Intervenor's Response, 2021‑02‑03.)
• Defensive value: Apple got no cancellation and no estoppel — it walked away with nothing but a § 314(d) dismissal. The only durable artifact is the Fintiv factor‑4 lesson: if you file an IPR on the '193 patent while the same art is in your district‑court contentions, expect a discretionary denial unless you stipulate away the overlap (or file a Sotera-style stipulation). That lesson is largely historical, because Fintiv discretionary denial has since been curtailed by USPTO guidance and rulemaking — a 2026 petitioner would not get the same free pass Maxell enjoyed in 2020.

IPR2018-00237 — ZTE Corporation v. Maxell, Ltd.

• Type: Inter Partes Review
• Patent: US 6,408,193 B1
• Filed: 2017‑11‑22 (effective 2017‑11‑22 per the Google Patents legal‑events entry; Docket Alarm: "Filed Nov. 22, 2017")
• Status: Institution Denied — Google Patents classifies it as "Not Instituted – Merits" (contrast the "Not Instituted – Procedural" label on IPR2020‑00203). A Notice of Refund was issued 2018‑06‑26, which is consistent with a denial of institution on or shortly before that date. I could not confirm the exact date of the denial decision from the sources retrieved.
• Judge panel: Lynne Pettigrew, Minn Chung, and Terrence McMillin (Art Unit 2683, Tech Center 2600) — per the Docket Alarm docket. Note Pettigrew and Chung sat on both '193 panels.
• Petition grounds: ⚠️ Not confirmed. I did not retrieve the petition or the denial decision for IPR2018‑00237, so I will not state the references, the statutory basis, or the challenged claims. What is confirmed is that ZTE filed a wave of IPRs against Maxell's asserted patents around the same date (the '193 filing sits in the IPR2018‑00209/‑00210/‑00233/‑00235/‑00236/‑00237/‑00238/‑00239/‑00240 cluster). For context only — and not a statement of the IPR ground — ZTE's district‑court invalidity contentions on the '193 patent involved the patent's own admitted prior art ("AAPA"), U.S. Pat. No. 5,107,225 ("Wheatley 225"), and U.S. Pat. No. 5,056,109 (the Qualcomm reference cited on the face of the '193 patent) (E.D. Tex. 5:16‑cv‑00179 correspondence, June 2018).
• Institution decision: Denied. Maxell's counsel summarized the outcome contemporaneously: the seven patents that went to verdict, including the '193 patent, each "survived IPR petitions filed by ZTE" (Jamie B. Beaber letter, 2018‑10‑09). The "merits" classification indicates the Board evaluated the substantive challenge and was not persuaded of a reasonable likelihood of unpatentability — but I have not verified the panel's reasoning and will not reconstruct it.
• Final Written Decision: None.
• Settlement / termination: No PTAB settlement. The underlying Maxell v. ZTE litigation (E.D. Tex. 5:16‑cv‑00179) produced an ~$43.3M jury verdict on 2018‑06‑29 across seven Maxell patents (the '193 patent among them) and then a confidential settlement announced 2019‑02‑04 that ended both the original and bifurcated (5:18‑cv‑00080) cases.
• Appeal: None. ZTE could not appeal a merits‑based non‑institution (§ 314(d)), and the district case settled.
• Defensive value: This is the more useful of the two proceedings for a defendant, even though the public record is thinner: the Board's rejection is labelled a merits disposition, meaning a ZTE‑grade obviousness/anticipation attack on the '193 patent was reviewed substantively and still failed to clear the § 314(a) threshold in 2018. But the caveat matters — no FWD means no estoppel, so that same art (and better art) remains fully available to a new petitioner.

Related post‑grant event (not an AIA trial, but you must know it)

Ex parte reexamination of US 6,408,193 — Google Patents legal events show a Request for Reexamination filed with effective date 2020‑12‑18, followed by a Reexamination decision confirming the claims, 2021‑11‑02 (effective date 2021‑10‑29, kind code C1, "REEXAMINATION CERTIFICATE"). No claims were cancelled or amended in substance — the certificate confirms the existing claims. I was unable to confirm the reexamination control number or the identity of the third‑party requester from the sources reviewed (Apple is known to have requested ex parte reexaminations of several Maxell patents in this campaign — see the "Appendix A — Apple Requested Ex Parte Reexaminations Of Maxell Patents," dated 2021‑03‑31, filed in a later proceeding — but I did not verify that Apple was the requester for the '193 reexam).

Defensive takeaway: the patent was tested a third time, at the examiner level, and came out unchanged. That is a modest hardening signal — the art of record did not impress the examiner either — but it is not an adjudication and carries no estoppel.

Strategic summary

Claim‑level status (this is the headline). The '193 patent has seven claims, all alive: independent claims 1 and 7, and dependent claims 2, 3, 4, 5, 6. Nothing has been cancelled — not at the PTAB (two non‑institutions, zero FWDs) and not in reexamination (C1 certificate confirming the claims). But the distinction between "alive" and "adjudicated" is doing a lot of work here: claims 1, 6, and 7 were the ones Apple challenged and never got reviewed; claims 2–5 have effectively never been tested in a post‑grant forum at all. The prior district‑court record is a mixed bag — ZTE obtained a jury finding of non‑infringement on one patent in the seven‑patent verdict but failed to invalidate the '193 patent, and Apple's § 103 invalidity theory against claims 1, 6, 7 (per the IPR2020‑00203 petition) died at the institution stage, never reaching a merits ruling. There is also at least a 2018‑era partial summary‑judgment skirmish over claims 1–7 in the ZTE case, where ZTE dropped its admitted‑prior‑art obviousness theory on the '193 patent as a mooted issue rather than lose it — i.e., that ground was abandoned, not adjudicated on the merits either.

Estoppel landscape — the key structural point is that there isn't any. Section 315(e)(2) estoppel attaches only after a final written decision. Both '193 proceedings were denied at institution, so neither Apple nor ZTE is estopped, and neither are their privies. That cuts two ways for a defendant today:

• Good news: a fresh petitioner faces no inherited estoppel and no adverse claim construction; the full prior‑art universe (Waldroup/Nakayama, Wheatley '225, the '193 patent's own AAPA, Qualcomm '109, and anything ZTE/ZTE privity hands over) is fair game, and any of it can be combined differently.
• Bad news: because the FWD never issued, Apple's and ZTE's institution‑stage art and expert work product is not public in adjudicated form, and the two denials give you no roadmap to why the merits failed — you get a "merits denial" label from ZTE's petition, not a reasoned validity finding. Any modern challenge starts effectively from scratch, but without the benefit of a prior panel's reasoning.
• There is also no § 315(a)(1)/325(a)(1) bar implicated here, and the one‑year § 315(b) clock is academic given expiration.

Pattern signals. The picture is a coordinated, multi‑front defense by a single patent‑assertion plaintiff against a series of implementers, not a defensive‑aggregator story:

1. Different petitioners, one patent — ZTE (2017) then Apple (2019). Not a serial‑filer pattern by one actor, but a pattern of the patent owner's litigation targets each filing — exactly the "well‑asserted patents eventually attract IPRs" dynamic the brief asks about, here with both arrows missing.
2. Two panels, overlapping membership — Pettigrew and Chung sat on both the 2018 (ZTE) and 2020 (Apple) '193 panels, and Chung/Pettigrew/Trock were the Apple panel. The same three APJs effectively controlled the '193 outcome twice, and the outcomes diverged (merits denial vs. Fintiv denial), which is a useful tell that the 2020 denial turned on Apple's failure to stipulate, not on any panel view of the merits.
3. The Fintiv‑era fortuity, now gone. IPR2020‑00203's denial rests on a doctrine (Fintiv factor 4, requiring a non‑overlapping‑art stipulation) that has since been narrowed by USPTO guidance and the post‑Sotera regime and largely abandoned in rulemaking. A 2026 petitioner who filed with a Sotera stipulation, or in the absence of a parallel trial date, would in all likelihood have gotten the petition instituted where Apple did not. Do not treat the 2020 denial as a merits endorsement of the '193 claims.
4. No Unified Patents in the chain. Maxell (f/k/a Hitachi Maxell) is the patent owner throughout; the current assignee is Maxell, Ltd. (following the Hitachi → Hitachi Consumer Electronics → Hitachi Maxell → Maxell → Maxell Holdings → Maxell chain). The challenges were implementer‑funded (ZTE, Apple), not defensive‑aggregator‑funded.
5. Patent owner has not pursued PTAB appeals aggressively — the only Federal Circuit activity on this patent is Apple's appeal of the denial (No. 2020‑2132), which Apple lost on jurisdiction, not Maxell's.

The expiration clock is the real defense. The patent's anticipated expiration is 2019‑11‑09 and its status is Expired – Lifetime. Under 35 U.S.C. § 286, damages are recoverable only for infringement occurring within six years before the complaint. Six years back from today (2026‑09‑28) reaches 2020‑09‑28 — which is after the patent expired. In plain terms: all infringement of the '193 patent predates the current six‑year damages window, so a complaint filed today against a new defendant would yield essentially no recoverable damages, regardless of how strong the infringement theory is. The window in which the '193 patent could support a live damages claim closed around November 2025. (This is my § 286 analysis on the dates of record, not legal advice — verify the expiration and any applicable extension/PTA before relying on it.)

Recommended next steps

• If you received a demand citing the '193 patent: the first response is not a PTAB argument — it is the calendar. Point to expiration 2019‑11‑09 (Google Patents legal‑events table, patents.google.com/patent/US6408193B1/en) and 35 U.S.C. § 286, and demand the theory under which any damages remain recoverable. Ask the sender to identify which claims it is asserting — since no claim has ever been cancelled, a demand can cite claims 1–7, but there is no FWD and no reexam cancellation to point to, so the invalidity story must be built from scratch.
• If you nonetheless want the PTAB record: pull the actual papers rather than relying on this summary. The public sources I located are: the Docket Alarm dockets for IPR2020‑00203 and IPR2018‑00237; the IPR2020‑00203 decision below at AppleMaxell_OpBelow.pdf; the Federal Circuit dismissal order at AppleMaxell_Denial.pdf; and RPX Insight at insight.rpxcorp.com/ptab/11159-apple-v-maxell-ltd-ipr-of-193. The IPR2020‑00203 denial is PTAB Paper 12 and the ZTE denial is the paper preceding the 2018‑06‑26 Notice of Refund — retrieve both from PTAB E2E / USPTO PTAB Decisions for the verbatim claim language and reasoning.
• Gap I could not close and you should: the IPR2018‑00237 denial date, grounds, challenged claims, and panel reasoning are not confirmed in any source I retrieved, and the reexamination control number and requester for the 2021 C1 certificate are not confirmed. Both are retrievable from PTAB E2E and USPTO PatentCenter/reexam file history respectively. I have deliberately left these blank rather than fill them by inference.
• No active proceedings exist, so there are no trial‑stage milestones to monitor — no institution deadline, no oral hearing, no § 318(a) one‑year FWD date. The '193 patent's PTAB chapter is closed at the institution stage, twice.

I'll verify the assignment records and look for correspondent-of-record details before building the chain.

Let me try to pull correspondent-of-record details from the assignment records themselves.

I could not complete live queries against assignmentcenter.uspto.gov within the search budget available, so the assignment chain below is reconstructed from the USPTO-sourced legal-events table carried in the authoritative patent text (Google Patents' rendering of the recorded assignment data, which mirrors AOTW/Assignment Center). Where I attempted to pull correspondent-of-record names, the results were inconclusive — I flag that explicitly rather than guessing.

Inventors

• Both inventors assigned their rights to Hitachi, Ltd. by an instrument executed 1999‑10‑14 and recorded 2002‑02‑19 at Reel 012592/0250.
• Pattern check — no anomaly. The assignment to the employer was signed roughly one month before the US filing date (1999‑11‑09) and about eleven months after the JP priority filing (JP 10‑318689, 1998‑11‑10). This is the ordinary, expected "employee inventors assign to corporate employer" arrangement. There is no evidence of inventors departing the assignee, no split inventorship, and no post‑filing re‑assignment back to the inventors. The "all inventors departed within 12 months" fire‑sale precursor pattern is not present.

Original assignee

Hitachi, Ltd. (Japan) — named in the issued patent and as assignee on Reel 012592/0250.

• Primary line of business: diversified industrial/consumer electronics conglomerate; at the time of filing it manufactured CDMA cellular handsets and the RF/power‑amplifier components the patent describes. The specification's "measured values obtained from power amplifier module for CDMA system in Japan" (col. description of FIGS. 10A/10B) indicates the assignee itself was fabricating the embodying hardware.
• Did they ship a product embodying the claims? The patent is directed to the transmit‑power/bias control architecture of a CDMA cellular telephone — Hitachi built CDMA handsets and RF power modules in this era, so this reads as a genuine product patent rather than a paper asset. (I could not independently confirm a specific Hitachi handset model number, so I state this at moderate confidence.)
• Current status of the original assignee: Hitachi, Ltd. is operating but has been through successive restructurings; its consumer‑electronics IP was spun out (Hitachi, Ltd. → Hitachi Consumer Electronics Co., Ltd. → Hitachi Maxell, Ltd.). The original assignee no longer holds the patent.

Assignment timeline

All six entries below are recorded assignments, in chronological order by recording date. The '193 patent's chain is entirely corporate re‑organization / name‑change driven — there is no transfer to a licensing shell or aggregator anywhere in the chain.

1999‑10‑14 (executed) / recorded 2002‑02‑19 — Reel 012592/0250

• Conveyance: Assignment of assignors' interest
• Assignor: Katagishi, Makoto; Machida, Shirou
• Assignee: Hitachi, Ltd. (Japan)
• Correspondent: not confirmed — the Google Patents legal-events rendering does not surface correspondent data, and my attempts to retrieve the correspondent attorney/firm for this reel were inconclusive. ⚠️ Unable to report; this is a data gap, not an absence of a correspondent.
• Context: initial inventor→employer assignment (executed pre‑filing, recorded post‑issuance, normal for the 1999–2002 era).

2012‑02‑15 (effective) / recorded 2012‑03‑12 — Reel 027842/0306

• Conveyance: Assignment of assignor's interest
• Assignor: Hitachi, Ltd.
• Assignee: Hitachi Consumer Electronics Co., Ltd. (Japan)
• Correspondent: not confirmed in retrieved sources.
• Context: internal corporate reorganization — carve‑out of Hitachi's consumer‑product IP into the consumer‑electronics subsidiary. Flag: Maxell's own pleadings describe this as a 2009 assignment ("in 2009 Hitachi, Ltd. assigned much of its consumer product‑facing IP to Hitachi Consumer Electronics"), while the recorded instrument is dated effective 2012‑02‑15. I report both literally; the recorded date governs the assignment record.

2014‑08‑26 (effective) / recorded 2014‑09‑08 — Reel 033694/0745

• Conveyance: Assignment of assignors' interest
• Assignor: Hitachi Consumer Electronics Co., Ltd. (recorded twice, as "Hitachi Consumer Electronics Co., Ltd." and "Hitachi Consumer Electronics Co, Ltd." — a duplicate‑assignor typographical artifact in the record)
• Assignee: Hitachi Maxell, Ltd. (Japan)
• Correspondent: not confirmed in retrieved sources.
• Context: internal corporate reorganization — the consumer‑electronics IP block (including this patent) moved into Hitachi Maxell. Maxell's complaints describe this as a 2013 transfer versus the recorded effective date 2014‑08‑26. Reported literally.

2017‑10‑01 (effective) / recorded 2018‑01‑25 — Reel 045142/0208

• Conveyance: Assignment of assignor's interest
• Assignor: Hitachi Maxell, Ltd.
• Assignee: Maxell, Ltd. (Japan)
• Correspondent: not confirmed in retrieved sources.
• Context: internal corporate reorganization / holding‑company transition — 2017‑10‑01 is the date Hitachi Maxell moved to a holding‑company structure and renamed itself; operating businesses (and the IP) were vested in the new "Maxell, Ltd." operating company.

2021‑10‑01 (effective) / recorded 2021‑11‑29 — Reel 058255/0579

• Conveyance: Merger
• Assignor: Maxell, Ltd.
• Assignee: Maxell Holdings, Ltd. (Japan)
• Correspondent: not confirmed in retrieved sources. (I did independently confirm this reel/frame number: a PTAB petition document quoting the assignment recites "recorded in the United States Patent and Trademark Office at Reel 058255, Frame 0579." It was recorded en masse covering a large Maxell portfolio, consistent with a corporate merger recording rather than a targeted transfer.)
• Context: merger — Maxell Holdings absorbed Maxell, Ltd. (announced 2021‑04‑28; effective 2021‑10‑01) as part of unwinding the holding‑company structure.

2021‑10‑01 (effective) / recorded 2021‑12‑03 — Reel 058666/0407

• Conveyance: Change of name
• Assignor: Maxell Holdings, Ltd.
• Assignee: Maxell, Ltd. (Japan)
• Correspondent: not confirmed in retrieved sources.
• Context: change of name only — the surviving holding company renamed itself "Maxell, Ltd.," restoring the operating name. No change in beneficial ownership.

Non‑assignment events that do not alter the chain (noted for completeness): Certificate of Correction recorded 2002‑11‑19; ex parte reexamination requested 2020‑12‑18 with Reexamination Certificate C1 issued 2021‑11‑02 confirming the claims; anticipated expiration 2019‑11‑09.

Timeline diagram

timeline
    title Ownership of US 6408193
    1999 : Inventors assign to Hitachi Ltd
    2002 : Patent issued
    2012 : Hitachi Ltd assigns to Hitachi Consumer Electronics
    2014 : Hitachi Consumer Electronics assigns to Hitachi Maxell
    2016 : First suit filed against ZTE
    2018 : Hitachi Maxell assigns to Maxell Ltd
    2019 : Patent expires
    2021 : Maxell Ltd merges into Maxell Holdings
         : Maxell Holdings renamed Maxell Ltd

NPE / troll-pattern signals

1. Shell-entity transfer — Not present. Every link in the chain stays inside one named corporate family of operating manufacturers: Hitachi, Ltd. → Hitachi Consumer Electronics → Hitachi Maxell → Maxell, Ltd. → Maxell Holdings → Maxell, Ltd. No "IP / Patents / Licensing / Ventures" suffix appears, no registered‑agent address, no single‑purpose LLC. (Maxell Holdings, Ltd. is a public‑company holding vehicle, but its link is a registered merger — reel 058255/0579 — not a transfer to a licensing shell, and it was undone by the 058666/0407 name change.)

2. Known asserter in the chain — Not present (with a caveat). The current owner, Maxell, Ltd., does not appear on the enumerated NPE lists (Acacia, Marathon, Intellectual Ventures, IPNav, Wi‑LAN, Mosaid/Conversant, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, Spangenberg entities). Maxell is a decades‑old operating manufacturer of batteries, storage media, projectors, and consumer electronics (per its complaints, e.g. Maxell v. Apple, W.D. Tex. 6:21‑cv‑00158, ¶1). Caveat: Maxell is surfaced by Unified Patents' litigation portal as a high‑frequency plaintiff in the 2016–2024 window (ZTE, Apple, Huawei, ASUSTeK, Samsung), and it runs an explicit licensing/enforcement program — an NPE‑adjacent characteristic, but not a match to any NPE classification.

3. Repeat correspondent across the chain — Unclear / unable to verify. The correspondent of record appears on none of the six entries in the authoritative data I hold, and my targeted retrievals for the correspondents on reels 012592/0250, 027842/0306, 033694/0745, 045142/0208, 058255/0579 and 058666/0407 were inconclusive. Because no correspondent names were recovered, I cannot assess recurrence — this is a data gap. I explicitly do not assert a repeat‑correspondent finding. (The six conveyances are all conventional corporate/merger filings, which typically route through the companies' own IP departments or long‑standing outside counsel, but that is an expectation, not a documented finding.)

4. Cascading transfers — Not present. The transfers are spaced years apart (2012, 2014, 2018, 2021) and track announced corporate restructurings. The only sub‑24‑month cluster is the 2021‑11‑29 merger + 2021‑12‑03 name change — both effective the same day (2021‑10‑01), recorded four days apart. That is a single two‑step internal reorganization (merge into the holding company, then rename the survivor), not a chain of unrelated LLCs. No shared‑principal / shared‑address LLC pattern.

5. Pre-litigation transfer — Not present. The first infringement suit naming this patent (Maxell v. ZTE, E.D. Tex. 5:16‑cv‑00179) was filed 2016‑11‑18. The nearest preceding assignment is Reel 045142/0208 (effective 2017‑10‑01, recorded 2018‑01‑25) — which actually post‑dates the suit filing, and the ownership it documents (Hitachi Maxell → Maxell) had been in place since at least the 2014 reorganization. There is no assignment within 6 months before the 2016 ZTE filing. The '193 patent was held inside the same corporate family for ~17 years before assertion.

6. Bankruptcy fire‑sale — Not present. Neither Hitachi, Hitachi Consumer Electronics, Hitachi Maxell, nor Maxell, Ltd. entered bankruptcy proceedings; the 2021 events are a solvent absorption‑type merger (per Maxell's own disclosure, the merger was a simplified/short‑form merger of a wholly owned subsidiary with no share allotment).

7. Privateering — Not present. Privateering requires an operating company to hand the patent to a separate NPE that asserts on its behalf. Here the operating company family asserts in its own name — Maxell, Ltd. is the plaintiff of record in every suit. No dedicated assertion vehicle appears in the chain. (Note: a US subsidiary, Maxell Research and Development of America, LLC, is referenced in Maxell's litigation as a licensing/R&D entity, but it is not in this patent's recorded assignment chain, so I do not treat it as a link.)

8. Defensive aggregator (anti‑NPE) — Not present. The chain does not terminate at RPX, AST, LOT Network, Unified Patents, or OIN. It terminates at Maxell, Ltd., an asserting operating company.

Verdict

Operating-company assertion.

Justification: The recorded chain (Reels 012592/0250 → 027842/0306 → 033694/0745 → 045142/0208 → 058255/0579 → 058666/0407) contains zero shell‑entity transfers, zero NPE‑list assignees, and zero transfers to a defensive aggregator — every link is an internal reorganization, merger, or name change within the Hitachi/Maxell corporate family, and the patent was asserted by Maxell, Ltd. in its own name against mobile‑device competitors (ZTE, decision 2016→2019; Apple, 2019→2021). Caveat I want on the record: the strict criterion for this verdict — that the current assignee ships products embodying the claims — is only partially satisfied. Maxell today sells batteries, storage media, projectors, and accessories, and I found no evidence it currently manufactures a CDMA cellular telephone; the embodying product (a Hitachi CDMA handset/RF module) belonged to the original assignee. So this is best read as assertion by a diversified operating manufacturer with an active licensing program, not by a true NPE and not by a pure paper‑title holder.

⚠️ Data limitation for verification: I was unable to query assignmentcenter.uspto.gov live or retrieve the correspondent‑of‑record for any of the six assignments; the reel/frame, dates, and conveyance types above come from the USPTO‑sourced legal‑events table in the authoritative patent text (independently corroborated for Reel 058255/0579 via a PTAB filing). If the correspondent names are needed for the repeat‑correspondent analysis (signal 3), they must be pulled directly from the Assignment Center abstract of title, which also renders the full chain for verification here: https://assignmentcenter.uspto.gov/ (search by patent number 6408193).

Cross‑reference note / contradiction flagged: The previously generated Litigation summary states the Hitachi→Hitachi Consumer Electronics transfer occurred in 2009 and the Hitachi Consumer Electronics→Hitachi Maxell transfer in 2013 (drawn from Maxell's pleadings), whereas the recorded assignment effective dates are 2012‑02‑15 and 2014‑08‑26. This is a pleading‑vs‑record discrepancy, not an error in either source; the recorded dates above govern the assignment record.

I'll research the specific prior-art references cited on the face of US 6,408,193. Let me run targeted searches to verify each citation and gather technical detail.

Good detail on the first several references. Let me research the remaining citations: Fujitsu JPH04277909, Toshiba US5737697, Sony JPH06252797, Mitsubishi US5732334, and Lucent US6175270.

Prior-Art Analysis — US 6,408,193 B1 ("Cellular telephone")

Scope note. Per your instruction, I confined the search to US 6,408,193 (application 09/436,502) specifically and did not pull results for the closely-numbered family members. I confirmed the patent's identity against the USPTO record as reflected on the Google Patents copy (title "Cellular telephone," inventors Katagishi & Machida, assignee Hitachi → Maxell; granted 2002-06-18; reexam certificate C1 issued 2021-11-02 confirming the claims) (US6408193).

What "the patent citations" means here. The patent's front page lists a "Patent Citations (9)" table — the nine references cited against the '193 patent (prior art), not its forward "Cited By" list. I analyze all nine below. (Forward citations such as the Apple/Skyworks "Continuous closed-loop power control" art are not prior art to the '193 patent and are excluded from the §102 mapping.)

Critical framing on §102. Anticipation under 35 U.S.C. §102 requires a single reference disclosing every element of a claim, arranged as claimed. On my reading, none of the nine references alone anticipates claim 1 or claim 7 in full. Several disclose individual elements of those claims and are strong §102 references for narrower concepts (or §103 combination material). I flag this honestly per reference rather than asserting anticipation that the references do not support.

Recall the two independent claims to map against:

• Claim 1: CDMA phone; receiver outputs a power-control signal derived from the cell-site's transmit-power-control signal; open-loop then closed-loop power control to converge transmit power; controller (CPU+memory) sets both the gain of the variable amplitude amplifier and the bias condition of the power amplifier using a set of bias-and-gain data stored in memory.
• Claim 7: same preamble, but the power amplifier contains a maximum-power detector; the controller controls only the variable-amplitude-amplifier gain using a function defining the relation between bias data and gain data stored in memory; the maximum-power detector controls the PA output power.

1. US 5,056,109 A — Gilhousen et al. (Qualcomm, Inc.)

• Filed / Issued: 1989-11-07 / 1991-10-08 | Appl. No. 433,031
• Title: Method and apparatus for controlling transmission power in a CDMA cellular mobile telephone system
• Description: The foundational CDMA power-control patent. Discloses a CDMA cellular system in which the mobile measures cell-site transmitted signal power and adjusts its transmitter power in the opposite direction (open loop), and additionally uses a power-control feedback scheme in which the cell-site measures received power and sends a command signal to the mobile to fine-tune its transmit power (closed loop). (US5056109; EPO family copy)
• §102 mapping (claims 1 & 7): This reference discloses the CDMA cellular-telephone environment (element A), the antenna/transmitter/receiver structure, and — materially — the "open-loop then closed-loop" power-control sequence (element H) that the '193 claims recite. It is therefore the most relevant reference for the power-control half of claims 1 and 7. It does not disclose the variable amplitude amplifier in combination with a separately bias-controlled power amplifier (element F), a CPU+memory controller storing a set of bias-and-gain data (elements G/I), or the maximum-power detector of claim 7 (element J).

2. US 5,129,098 A — McGirr (Novatel Communication Ltd.)

• Filed / Issued: 1990-09-24 / 1992-07-07
• Title: Radio telephone using received signal strength in controlling transmission power
• Description: Uses the received-signal-strength indicator (RSSI) as a proxy for propagation conditions to control the gain of the transmitter's variable power amplifier. The control loop derives the control signal from look-up tables stored in memory (calibration table, target-transmission-power table, power-control-signal table), driven by an on-board CPU/DAC/AGC loop. (US5129098)
• §102 mapping: Directly relevant to the "receiver outputs a signal (strength) used to set transmitter gain" element and to the memory-stored data element (elements D/I). It anticipates a narrow claim to "use received-signal strength plus a memory look-up table to set power-amplifier gain." It does not disclose CDMA, the closed-loop cell-site command path, the variable-amplitude-amp + separately-biased PA combination, or bias-condition control — so it cannot anticipate claims 1 or 7.

3. JP H04-277909 A — Fujitsu Ltd.

• Filed / Published: 1991-03-06 / 1992-10-02
• Title: Transmission power control method (Japanese published application)
• Description: A transmit-power-control method for radio equipment. The full text is Japanese-language pre-1995 art; the '193 background cites it (along with Hei-06-252797) as generic further related art rather than as the teaching the invention builds on. I was unable to retrieve a full English claim/text rendering within this search, so I decline to attribute specific structural features beyond its title-level subject matter.
• §102 mapping: Generic transmission-power-control art (element H context). I cannot, on the available record, map it to a complete claim; treat it as background/§103 material only.

4. US 5,128,629 A — Trinh (Hughes Aircraft Company)

• Filed / Issued: 1991-04-22 / 1992-07-07
• Title: Method for controlling the output power of digital cellular telephones
• Description: A controlled power-amplifier system in which a sample of the PA output is compared with a reference to produce a power-level control signal. Notably, the controller outputs a pulse-width-modulated (PWM) waveform whose duty cycle is proportional to the control voltage, and a low-pass filter removes the AC component leaving a DC set-point — i.e., a PWM-based D/A conversion into a smoothed DC control voltage. (US5128629 via Espacenet; US5128629 PDF)
• §102 mapping: This is the most on-point reference for dependent claims 2 and 3 (and 4/5): it discloses PWM generation of a control voltage (claim 2) and a smoothing/low-pass circuit (claim 3). Caveat: in US5128629 the PWM signal sets a power-level set point, not a power-amplifier bias condition, so it does not literally anticipate claims 2/3 as those claims are tied to "bias control signal" — it is best characterized as §103 combination art against the PWM/smoothing dependent claims. It does not touch claim 1 or 7's coordinated gain+bias memory control.

5. US 5,737,697 A — (Toshiba Corporation)

• Filed / Issued: 1993-01-25 / 1998-04-07
• Title: Transmission power control circuit for a communication system
• Description: A transmission-power-control circuit for a radio communication system (Toshiba). The examiner-cited reference. I was unable to retrieve the full text within the search budget, so I limit my characterization to its title-level subject matter (a transmit-power-control circuit) rather than asserting specific elements.
• §102 mapping: Transmit-power-control-circuit art (element H context). On the available record it does not map onto a complete claim; §103 material only.

6. JP H06-252797 A — Sony Corp.

• Filed / Published: 1993-02-23 / 1994-09-09
• Title: Transceiver (Japanese published application)
• Description: Cited in the '193 background alongside Hei-04-277909 as further related art. Title-level subject matter is a transceiver; I could not retrieve a full English rendering.
• §102 mapping: Background §103 material only; no basis to map to a complete claim.

7. JP H09-046152 A — Hitachi Ltd. ★ (closest art)

• Filed / Published: 1995-07-28 / 1997-02-14
• Title: Wireless transceiver
• Description: This is the reference the '193 specification discusses by name ("Japanese Patent Laid-open No. Hei-9-46152"). It discloses a mobile unit whose transmitter has a variable amplitude amplifier for adjusting transmit power and a high-frequency power amplifier using a FET, where the bias condition (gate voltage) of the FET is controlled according to the transmission power. Attenuation and the corresponding FET gate voltage are set in discrete steps (e.g., 4 dB), and the gate voltage is reduced at low transmit power to cut current consumption and extend battery life. (Referenced at Google Patents JP2000151317A / JPH0946152 and reproduced in the '193 background.)
• §102 mapping: This is the most relevant reference for the core inventive concept — controlling a power amplifier's bias condition as a function of transmit power to save current (the heart of claim 1's element I and claim 7's element J). A claim drawn merely to "vary power-amplifier bias with transmission power to reduce current consumption" would be anticipated by this reference. However, it does not disclose (a) the CDMA open-loop-then-closed-loop control of claims 1/7, (b) a controller storing a set of bias-and-gain data in memory to jointly drive a variable amplitude amp and the PA, or (c) the maximum-power detector of claim 7. The '193 patent positions itself explicitly as improving this reference (stepped 4-dB bias control → continuous/function-based coordinated gain+bias control; abrupt bias switching → gradual). So it is the principal §103 starting point rather than a full §102 anticipator of claims 1/7.

8. US 5,732,334 A — Miyake (Mitsubishi Denki K.K.)

• Filed / Issued: 1996-07-04 / 1998-03-24
• Title: Radio transmitter and method of controlling transmission by radio transmitter
• Description: APC circuitry for a radio transmitter: a detector samples the RF output, an integrator produces an average power signal, and a digital control unit (CPU) computes an error vs. a reference power level, applies a correction coefficient, and generates corrected control data that sets a variable-gain element to maintain a prescribed output power. (US5732334)
• §102 mapping: Relevant to the "controller comprising a central processing unit" and stored/reference-value elements (element G) and to closed-loop APC. It is a US patent whose §102(e) date (1996-07-04 filing) predates the '193 priority (1998-11-10), so it is available as §102(e) art. It does not disclose the variable-amplitude-amp + separately-biased-PA combination, CDMA, or the memory-stored bias-and-gain data set — no anticipation of claims 1/7.

9. US 6,175,270 B1 — (Lucent Technologies Inc.)

• Filed / Issued: 1998-03-05 / 2001-01-16
• Title: Method and apparatus for tailored distortion of a signal prior to amplification to reduce clipping
• Description: Predistortion/clipping-reduction technique that shapes a signal before amplification to reduce clipping in a (CDMA-type) power amplifier — i.e., linearity/efficiency art rather than power-control art. Its US filing date (1998-03-05) precedes the '193 priority date (1998-11-10), so it qualifies as §102(e) prior art notwithstanding its later 2001 issue date.
• §102 mapping: Peripheral to claims 1/7; it bears on the amplifier-linearity constraints that motivate bias selection (the '193 spec notes bias is chosen to satisfy adjacent-channel leakage). It does not disclose any claimed structural element and does not anticipate claims 1 or 7.

Overall assessment — most relevant prior art

Ranked relevance to the '193 claims:

Bottom line: The cited references collectively disclose (i) the CDMA open-loop/closed-loop power-control framework, (ii) power-amplifier bias control keyed to transmit power for current savings, and (iii) PWM-plus-filter control-signal generation. No single cited reference discloses the full claim 1 combination — in particular the memory-resident set of bias-and-gain data jointly driving a variable amplitude amplifier and the PA bias under an open-loop-then-closed-loop CDMA sequence — nor the maximum-power-detector delegation of claim 7. The patent's novelty therefore rests on the coordination of gain and bias via stored data (and the claim-7 detector arrangement), which is why validity is best evaluated under §103 combinations of (1)+(2) rather than §102.

Supplementary (not in the citation table, but the actual validity art): In IPR2020-00203 Apple challenged claims 1, 6, and 7 under §103 over Waldroup in view of Nakayama; institution was denied on discretionary (Fintiv/§314(a)) grounds, and the ex parte reexamination (certificate 2021-11-02) confirmed the claims. These references — not the nine front-page citations — were the references that mattered to the patent's actual validity contests; I flag them because they do not appear in the "Patent Citations (9)" table you asked me to walk.

Caveats / limits: (a) I was unable to retrieve full English text for the three Japanese references (H04-277909, H06-252797) and for US 5,737,697 within the search budget, so those entries are limited to title-level characterization rather than element-by-element §102 mapping — I did not guess at their contents. (b) All claim-element mappings above are grounded in the authoritative full patent text you supplied; where my search results differed in wording, I deferred to the patent text. (c) The §102(e)-date observations for US 5,732,334 and US 6,175,270 assume their U.S. filing dates precede the '193 priority date of 1998-11-10 as listed; note the family-table discrepancy (1998-10-11 vs. 1998-11-10) flagged in the earlier bibliographic section, which does not change these two conclusions.

I'll build the §103 analysis on the prior-art record already established, but first let me try to pin down the two references that actually mattered in the Apple IPR (Waldroup and Nakayama), since those are the most probative combination of record.

Let me identify the Nakayama reference and confirm the Waldroup patent number, since these are the two references of record in the actual §103 challenge.

Let me make one focused attempt to identify the Nakayama reference by its disclosure text, then I'll build the analysis.

Obviousness Analysis of US 6,408,193 B1 under 35 U.S.C. § 103

Building on: the bibliographic, litigation/PTAB, assignment, and prior-art sections already generated for this patent. This section does not repeat the nine front-page citations' descriptions; it extends them, adds the two references that actually drove the validity contest, and maps them claim-element by claim-element.

0. Framework and one important gap I must flag first

Legal framework. Obviousness under § 103 is assessed under the Graham v. John Deere factors — scope/content of the prior art, differences between the art and the claims, level of ordinary skill, and objective indicia — with the KSR Int'l v. Teleflex gloss that a motivation to combine need not be found in the references themselves. A KSR rationale may be: (i) a known technique used to improve a similar device; (ii) a simple substitution of one known element for another; (iii) a predictable variation ("obvious to try"); (iv) a design incentive or market pressure; or (v) an express TSM teaching. This patent is squarely a KSR case: the "invention" is a coordination/control refinement of admitted prior art, not a new architecture.

⚠️ Gap carried forward. My earlier sections flagged that the actual validity art — Waldroup in view of Nakayama (IPR2020-00203) — is not in the patent's own "Citations (9)" table. I have now confirmed Waldroup = U.S. Pat. No. 6,236,863 B1 ("Comprehensive transmitter power control system for radio telephones," Waldroup, Lyall & Bain; assignee Oki Telecom, Inc.; filed 1998-03-17; issued 2001-05-22), verified against Google Patents US6236863, everypatent US6236863, and the E.D. Tex. invalidity contentions (Docket Alarm, 5:19-cv-00036, Doc. 343 Ex. D3 and Doc. 348 Ex. D2).

I could not confirm the bibliographic identity or publication date of the Nakayama reference, despite targeted searching. What I can confirm from the contentions record is its disclosed subject matter (an apparatus with "communicator 11," variable attenuator 18, variable-bias amplifier 19, CPU 26, detector circuit 31, memory 45, bias-voltage-control part 43, DC/DC converter 49). I therefore state no patent number for Nakayama, and I flag that its precise § 102 category (§ 102(b) pre-1998 publication vs. § 102(e) U.S. filing) is unverified. This matters because the '193 priority date is on the record only as 1998-11-10 (JP 10-318689), and the family table on the same page also renders 1998-10-11 — a discrepancy flagged in the bibliographic section. Any Nakayama date must be checked before relying on it.

1. The claim elements to be mapped

Carried forward from the claim analysis. I attach the same element letters I used in the prior-art section so the mapping is continuous.

Claim 1 (independent):

Claim 7 (independent): elements A–H as above, plus:

Dependent claims: 2 (PWM pulse width sets bias) · 3 (+ smoothing circuit) · 4 (PDM pulse density sets bias) · 5 (+ smoothing) · 6 (signal generator driving both amps).

Claim construction note. The E.D. Tex. court construed the "bias" terms of '193 claims 1 and 7 in Maxell Ltd. v. Huawei Device U.S. Inc., 297 F. Supp. 3d 668 (E.D. Tex. 2018) (the consolidated pretrial order covering the ZTE-asserted '193 patent). I have not reproduced the exact construction language because I could not verify it verbatim in this session; the construction of "bias condition" is the single most outcome-determinative issue for Grounds A and B below, and it should be pulled from the opinion before any § 103 opinion is finalized.

2. The prior art universe — the two references that matter

Adding to the ranked table in the prior-art section (which remains valid), the decisive validity art is:

Waldroup — US 6,236,863 B1 (Oki Telecom; filed 1998-03-17; issued 2001-05-22). Discloses a CDMA radio telephone with open-loop + closed-loop gain control, an antenna (26), a duplexer (28), a receive chain, a transmitter with an adjustable-gain IF transmitter amplifier (the claimed "variable amplitude amplifier"), a directional coupler (50), and a logic circuit implemented as a specially-programmed CPU. Critically it discloses:

• Open-loop then closed-loop sequencing in CDMA: the patent states a CDMA mobile station "shall provide two independent means for output power adjustment: open loop estimation … and closed loop correction." (Waldroup's own "Definitions" section, Google Patents.)
• Memory-stored, incrementally-stepped gain values: "the closed loop range is divided into equal steps represented by incremental memory values corresponding to one dB units of gain" (Waldroup 3:5–20).
• A pulse-density modulator: "a closed loop power control register which is functionally connected to a pulse density modulator within a mobile station modem ASIC … to provide an analog output representation of the value stored in the register" (Waldroup, Definitions).
• Maximum-power detection and limiting: the output detector/comparator and the logic circuit that "continually" checks maximum power and "decrement[s] the closed loop power control register" until output falls below the trigger level (Waldroup 4:8–18, 4:61–5:xx), disclosed as CPU-based ("a specially-programmed central processing unit (CPU)").

Nakayama (identity unconfirmed — see § 0). Discloses a transmission-power control circuit in which memory 45 stores, for each "reference transmission power," a set of associated values: a reference signal level (gain) datum, a reference bias voltage control datum for amplifier 19, and a reference attenuation datum for variable attenuator 18 (contentions quoting Nakayama ¶¶ [0026]–[0029], [0047]). It discloses a central processing unit 26, a detector circuit 31 that detects output and from which the CPU determines whether output is at a maximum reference transmission power (¶¶ [0023], [0046]), and a DC/DC converter 49 that applies the reference bias voltage to amplifier 19 (¶ [0047]). Nakayama's FIG. 5 (admitted prior art) shows exactly the claimed topology: "variable attenuator 3 having a variable attenuation rate, then amplified by a power amplifier 4 having a variable bias voltage" (¶ [0003]).

3. Ground A — Waldroup + Nakayama (the ground of record)

This is the combination Apple reduced to a § 103 petition in IPR2020-00203 and to invalidity contentions in Maxell v. Apple. Institution was denied on Fintiv/§ 314(a) grounds — a procedural denial that says nothing about the merits (see the PTAB-challenges section). So this ground is unadjudicated, not rejected.

Motivation to combine (verbatim from the record — this is the strongest part of the ground): Apple's contentions state the rationale expressly, and it is a classic KSR design-incentive rationale:

"It would be obvious to modify Nakayama's mobile phone using the CDMA teachings of Waldroup to operate in a CDMA network. The motivation to do so would be to enjoy the improved power efficiency of Nakayama's phone in a CDMA network."

"The motivation to combine Nakayama's transmission power control circuit into Waldroup's CDMA telephone would be to improve the power efficiency of a CDMA handset, which is taught as being desirable by Waldroup. … The known work of Nakayama in the field of TDMA transmission power control would prompt a variation thereof in the field of CDMA transmission power control based on the design incentive of 'efficient operation of a CDMA wireless telephone system,' and this variation would be predictable to one of ordinary skill in the art."

(Doc. 348 Ex. D2.)

That is: (1) both references are in the same field (mobile-station transmit power control); (2) Waldroup itself supplies the design incentive (battery life / efficient CDMA operation); (3) the variation is asserted to be a predictable one. Under KSR, a design incentive articulated in the primary reference, plus a secondary reference solving the same problem by a known technique, is a textbook prima facie case.

Alternative primary/off-the-shelf. Apple also ran a parallel ground Waldroup in view of Geller (Doc. 343 Ex. D3), where Geller is "directed to efficient transmission of RF signals" in phased-array communications. This is a weaker secondary reference (more distant field), and I'd treat it as a fallback rather than the lead.

4. Ground B — Qualcomm '109 + Hitachi H09-046152 + Novatel '098 (built from the patent's own citations)

If a challenger preferred to stay within the patent's own citation list — which pre-empts any "new art" objection — claim 1 falls to a three-reference combination:

1. US 5,056,109 (Gilhousen/Qualcomm) supplies A (CDMA), B/D (cell-site power-control commands to the mobile), and H (open-loop and closed-loop power control — the entire sequence the '193 claims recite). This is the foundational CDMA power-control patent and is cited on the face of the '193 patent.
2. JP H09-046152 (Hitachi) supplies F and I — the variable amplitude amplifier plus high-frequency power amplifier whose FET bias (gate voltage) is controlled according to transmission power, stepped in discrete increments (e.g., 4 dB), to reduce current consumption and extend battery life. The '193 specification discusses this reference by name and positions the invention as an improvement on it (stepped/abrupt → gradual/function-based). An "improvement to a known device" framing is the KSR predictable-variation rationale in its purest form.
3. US 5,129,098 (McGirr/Novatel) supplies G and the memory-look-up aspect of I — using RSSI plus look-up tables stored in memory, driven by a CPU/DAC loop, to set transmitter gain.

Motivation. All three: (a) are in the same field; (b) H09-046152 and Novatel both expressly target the same problem the '193 patent states — battery life / current consumption; and (c) Qualcomm '109 supplies the CDMA framework that IS-95 (admitted prior art in the '193 spec) mandates. The '193 patent's own background admits that a transmitter applying IS-95 with a variable amplitude amplifier 230 and power amplifier 250, controlled by a controller 380 with a level-detecting means 390 supplying bias, is prior art ("AAPA"). So the only remaining delta is how smoothly/continuously the coordination is done — a routine engineering choice.

5. Dependent claims 2–6

These have essentially never been tested in any post-grant forum (see the PTAB section: Apple challenged only 1, 6, 7; ZTE's denial is unconfirmed as to scope). They are also the easiest to invalidate, because each recites a single well-known circuit technique:

• Claim 2 (PWM sets bias): US 5,128,629 (Trinh/Hughes) discloses a controller that outputs a PWM waveform whose duty cycle is proportional to the control voltage. Combine with Waldroup (which supplies the CDMA controller/memory context) or with Nakayama's bias-voltage control part 43. The only gap is that in Hughes the PWM sets a power-level set point rather than a bias condition — so the mapping turns on the construction of "bias," and I'd run this as a § 103 ground, not § 102.
• Claim 3 (smoothing circuit): Hughes '629 discloses the low-pass filter that removes the AC component of the PWM to leave a DC set-point. Nakayama's own architecture (DAC 47/48 → DC/DC converter 49 → amplifier 19) is a smoothing/level-shifting stage. Strong § 103.
• Claim 4 (PDM sets bias): Waldroup itself discloses a "pulse density modulator" driving the closed-loop register representation. This is the rare case where the primary reference literally names the modulation scheme of a dependent claim.
• Claim 5 (PDM + smoothing): as above, plus Hughes' low-pass or Nakayama's DC/DC.
• Claim 6 (signal generator feeding both amps): Nakayama's "attenuation control unit 42," "bias voltage control 43," DACs 47/48 and DC/DC 49 are mapped by Apple to the claimed "signal generator" (Doc. 348 Ex. D2, element [6(a)]). Also Nakayama's FIG. 5 shows a common control block driving both the variable attenuator and the variable-bias amplifier.

Motivation for the dependent-claim combinations: reducing controller pin count / wiring and simplifying the control interface (the '193 spec's own stated benefit for claim 6) is an ordinary design objective; and PWM/PDM-with-filtering was a known, cost-driven alternative to a high-resolution DAC — the '193 spec says exactly that ("the D/A 350 … will cost very much expensive"). A cost-motivated substitution of a known technique is a KSR rationale, not a patentable advance.

6. Secondary/tertiary references

• US 5,732,334 (Miyake/Mitsubishi) — a CPU computing error against a reference and generating corrected control data to a variable-gain element; corroborates element G (and CPU-based closed-loop APC generally). § 102(e) art (filed 1996-07-04).
• US 6,175,270 (Lucent) — amplifier linearity / clipping-reduction; supports the why of bias selection (adjacent-channel leakage, which the '193 spec says constrains the bias choice). Peripheral; not needed for any ground, but useful to rebut a "bias-to-save-current was somehow nonobvious" argument.
• US 5,737,697 (Toshiba), JP H04-277909 (Fujitsu), JP H06-252797 (Sony) — generic transmit-power-control art; background only, as noted in the prior-art section.

7. Motivation-to-combine synthesis (the KSR rationales, stated cleanly)

For a § 103 opinion, I would plead these rationales in parallel, since only one needs to hold:

1. Design incentive stated in the art itself. Waldroup's own text makes "precise mobile station power control … important … for proper and efficient operation of a CDMA wireless telephone system" (1:32–34). That is an express motivation to adopt any technique that improves efficiency.
2. Same field / same problem. Waldroup, Nakayama, H09-046152, Novatel, and Hughes all address mobile-station transmit power; the '193 patent identifies the problem as current consumption / battery life, which H09-046152 and Novatel expressly address.
3. Predictable variation ("obvious to try"). The '193 patent's advance over admitted prior art is gradual vs. stepped bias control and storage of a coordinated bias-and-gain set vs. a single fixed bias. Moving from a stepped to a continuous/table-driven control, or from one fixed bias to a stepped-down bias keyed to gain, is the kind of finite number of identified, predictable solutions that KSR holds obvious. The patent's own FIG. 10A/10B discussion frames the benefit as a ~14% current reduction — a quantitative, expected efficiency improvement, not a new capability.
4. Known technique used to improve a similar device. Look-up-table/function-based gain control (Novatel '098, Waldroup's incremental memory values) applied to a power amplifier whose bias is power-keyed (H09-046152, Nakayama) is a combination of two known techniques each doing what it was known to do.
5. Cost/market pressure. The '193 spec concedes the DAC is expensive and that PWM/PDM would be cheaper — supplying the motivation for claims 2–5 directly from the specification.

8. Where a § 103 case could still fail — and what to watch

I flag these honestly, because an all-upside analysis would be unreliable:

• Claim construction of "bias condition." If "bias condition" is construed broadly (any operating-point/DC-level control of the PA, including supply voltage or gain-adjacent control), Grounds A and B map cleanly. If it is construed narrowly (e.g., only quiescent DC bias of the amplifying device, excluding supply/DC-DC or variable-attenuator stages), Nakayama's DC/DC-converter-to-amplifier-19 disclosure and Waldroup's adjustable-IF-amp disclosure become harder to map to element I/K, and the ground weakens. This is the crux; I could not verify the Huawei construction text.
• Asserted "teaching away." The '193 spec frames the prior art's abrupt bias switching (crossing a threshold) as the problem, i.e., it might be argued the art taught away from gradual bias change. On the record I hold, the art teaches discrete stepping (H09-046152, 4 dB steps) rather than a warning against gradual control, so I would expect a "teaching away" argument to be weak — but it is the most plausible non-obviousness argument, and it goes to whether the change is a predictable variation.
• Objective indicia (secondary considerations). None are documented in my sources: no evidence of unexpected results, licensing-due-to-validity, commercial success, copying, or a long-felt need tied to the specific coordinated-bias feature. Notably, the "'193 patent survived" ZTE's IPR and the 2021 ex parte reexamination confirming the claims cuts the other way as a modest validity signal — but a confirmed reexam is not an adjudication of the Waldroup + Nakayama ground (that art was not the reexam art), and a non-institution is not a merits win. I would not treat either as strong secondary evidence.
• Nakayama's date is unverified. Everything in Ground A depends on Nakayama being § 102(a)/(b)/(e) art as of 1998-11-10 (or 1998-10-11). If Nakayama's date does not qualify it, Ground A collapses to Waldroup-alone-plus-a-non-prior-art-reference, and a challenger must substitute Hughes '629 / Novatel '098 / Mitsubishi '334 for the bias-and-gain-memory teaching.
• Waldroup's status is robust. Filed 1998-03-17, well before either candidate priority date, so it is qualifying art either way — that part of the ground is stable.

9. Bottom line

• Most probable path to invalidity: Waldroup (US 6,236,863) + Nakayama, applied to claims 1, 6, 7. Waldroup alone supplies the CDMA environment, the antenna/duplexer/receiver, the variable-amplitude-amplifier-plus-PA topology, the CPU+memory controller, the open-loop-then-closed-loop sequencing, the memory-stored incremental gain values, the pulse density modulator, and maximum-power detection/limiting. Nakayama supplies the memory-resident bias and gain data set and the maximum-reference-power bias control of the PA. The motivation is not merely inferable — it is stated in the contentions and, more importantly, in Waldroup's own text (efficiency of CDMA operation).
• Independent claims 1 and 7 are, on this record, vulnerable. Claim 1's only real delta over the combination is coordination via a stored set, which the art teaches as a table/function; claim 7's delta is delegating PA limiting to a maximum-power detector, which both Waldroup and Nakayama teach.
• Dependent claims 2–6 are more vulnerable still, each reciting a single known technique (PWM/PDM modulation; RC/low-pass smoothing; a shared control-signal generator), with the motivation (cost and wiring reduction) conceded in the specification.
• The strongest defense is not the merits — it is claim construction of "bias condition," plus the fact that the ground was never adjudicated. The two PTAB denials were non-substantive (one Fintiv, one merits-without-reasoning on an unconfirmed ground), so no estoppel and no reasoned merits win attaches to either side.
• Practical caveat, per the earlier sections: the patent expired 2019-11-09, and any damages window has closed — so a § 103 challenge today is an academic exercise unless it is defensive against a demand letter, in which case the calendar (35 U.S.C. § 286) is a faster answer than the prior art.

Unverified items I am deliberately not asserting: Nakayama's patent number and date; the exact Huawei construction of "bias"; the grounds actually relied on in IPR2018-00237. Each should be confirmed from the primary documents — AppleMaxell_OpBelow.pdf, the Maxell v. Huawei 297 F. Supp. 3d 668 opinion, and the IPR2018-00237 petition/denial on PTAB E2E — before any of the above is filed.