US 8102074

I'll run targeted searches for this specific patent number and for any 2026 CAFC activity.

The general searches returned noise. Let me try more specific queries against patent-specific and court-specific sources.

Summary of US Patent 8,102,074

I searched for this specific number (and for 2026 CAFC activity tied to it). Here is what I can confirm, and where I have to flag uncertainty.

Bibliographic data (confirmed)

Sources: Google Patents (https://patents.google.com/patent/[US8102074B2](/patent/US8102074B2)/en), uspto.report (https://uspto.report/patent/grant/8102074), and the patent PDF (patentimages.storage.googleapis.com/08/f0/2a/d8aea7cc33c70c/US8102074.pdf).

Ownership caveat: the "current assignee" field is not simple. Google Patents lists both Tigo Energy Innovations LLC and Newlight Capital LLC, and shows a chain of security interests and assignments (Western Alliance Bank 2018; UMB Bank as trustee / Newlight Capital 2020; release 2023; Newlight Capital 2025 corrective assignment; assignment to Tigo Energy Innovations LLC recorded 2026-01-20). The underlying inventive entity and original assignee are Tigo Energy, Inc. I would not treat the current owner as settled without checking the USPTO Assignment database directly.

Abstract (verbatim)

"Apparatuses and methods are disclosed for regulating or limiting the voltage output from solar modules connected in series such that the voltage on a string bus connecting those solar modules does not exceed regulatory or safety limitations. This can be accomplished via a controller, local management units (for downconverting solar module voltage output), or a combination of the two."

Independent claims in plain language (3 independents: 1, 8, 16; 19 claims total)

Claim 1 — system. An energy production system with: a string bus; first and second solar modules each connected to the bus and each generating its own voltage; a single controller configured to limit at least one of those two voltages as provided to the bus; and a first and a second local management unit (LMU), each coupled between its respective solar module and the bus and each in communication with that single controller. Plain reading: the architecture is one central controller plus one per-module LMU. Note claim 1 as granted does not recite the "maximum regulatory safety voltage" or "predicted future voltage" limitations.

Claim 8 — system. An energy production system with: a string bus; a solar module connected to the bus and generating a voltage; and a controller in communication with the module and the bus, configured to control the voltage provided to the bus based on a predicted future voltage as predicted by the controller and a maximum regulatory safety voltage. Plain reading: the control input is a forecast (the controller's own prediction of a future voltage), bounded by a regulatory safety ceiling.

Claim 16 — method. Monitoring a first voltage across a first string-bus section connecting a first solar module to a second solar module; monitoring a second voltage across a second string-bus section connecting the second solar module to a voltage output; and limiting the voltage output based on a maximum regulatory safety voltage by limiting the voltage of at least one of the first and second solar modules. Plain reading: sense voltages on two bus segments, then throttle one or both modules to stay under a regulatory ceiling.

Dependent claims add: the controller commanding both LMUs (2); the "controller" itself being constituted by the LMUs (3); switchable connections (4); transistor switches (5); duty-cycle and phase control (6); prevention of exceeding a predefined limit (7); disconnect switch (9); duty-cycle adjustment (10); transistor switch (11); prediction based on a voltage trend (12); a default/fallback voltage (13) triggered when a voltage threshold is exceeded (14); module connected via an LMU (15); threshold-based limiting (17); duty-cycle control of first and second switchable connections (18); and limiting based on predicted future voltage (19).

CAFC 2026 docket search

I found no CAFC appeal, IPR appeal, or 2026 Federal Circuit docket entry naming US 8,102,074. The closest Tigo-related appellate item I located is SMA Solar Technology America, LLC v. Tigo Energy, Inc., Fed. Cir. No. 2025-1344, which was dismissed for failure to prosecute on May 12, 2025, with the mandate issued June 18, 2025 (Patexia docket: https://services.patexia.com/lawsuits/SMA-Solar-Technology-America-LLC-v-Tigo-Energy-Inc-id-[206378](/patent/206378)/documents). Nothing there indicates this patent is on a 2026 CAFC docket. Tigo's publicly announced patent campaigns (e.g., the Feb. 21, 2023 SunSpec suit, and a suit involving "six patent infringement claims against SMA Solar Technology America LLC") concern rapid-shutdown/MLPE patents; I cannot confirm from my sources that 8,102,074 was asserted in any of them.

Explicit uncertainties

• No CAFC verification: my searches did not retrieve Federal Circuit docket records directly, so "no 2026 CAFC activity" means not found, not affirmatively confirmed absent. Docket-level checking on PACER/CAFC CM-ECF or USPTO PatentCenter would be required to state that definitively.
• Claim 16 text: the Google Patents rendering of claim 16 is truncated mid-sentence ("monitoring a first voltage across a first st"). The full wording I give above is taken from uspto.report's rendition of the granted claims, which matches the patent's independent-claim structure.
• Do not conflate related documents. US 20120119584 and US 8,274,172 share the title and specification but have different claim sets — e.g., their claim 1 recites controlling based "at least in part on a maximum regulatory safety voltage," which is absent from granted claim 1 of 8,102,074. US 8,274,172 is also subject to a terminal disclaimer. Any claim-charting or validity analysis must use the granted text of the specific patent.
• Current ownership as described above should be verified in the USPTO Assignment database rather than inferred from aggregator "current assignee" fields.

I'll run targeted searches against litigation-specific sources for this patent number.

Let me target litigation databases directly.

Bottom line

No litigation naming U.S. Patent No. 8,102,074 has been found. Not as an asserted patent, not as an adjudicated patent, and not in any 2026 filing. I cannot supply plaintiff/defendant/jurisdiction/case-number/filing-date/status fields because there are no cases to populate them with.

This is consistent with the prior sections of this analysis (the summary and PTAB sections, which also found no assertion). I found no contradiction to flag.

Known litigation involving US 8,102,074

I will not manufacture a table row to fill this template.

What I searched

• Queries pairing the patent number directly with litigation terms: "8,102,074" patent litigation; "8102074" patent infringement lawsuit; patent 8102074 litigation docket; docketalarm "8102074"; unifiedpatents.com litigation "8102074".
• Assignee-side queries targeting the current owner: Tigo Energy Innovations LLC lawsuit patent 8,102,074; "Tigo Energy Innovations" complaint infringement 2026; "Tigo" patent lawsuit 2026 filed district court.
• Results were cross-checked against Tigo's own enforcement disclosures and the two live Tigo district-court campaigns, both of which identify their asserted patents explicitly.

Why I am reasonably confident the negative is real (not just unindexed)

The '074 is not among the patents asserted in any Tigo enforcement campaign I could identify, and in each instance the asserted patents are enumerated on the record:

• Tigo Energy Inc. v. SMA Solar Technology America LLC, No. 1:22-cv-00915-GBW (D. Del.), filed 2022-07-11 — asserts U.S. 8,823,218; 8,933,321; 9,584,021; 9,966,848; 10,256,770; 10,333,405. The '074 is absent. This case settled 2025-05-13 ("Tigo Energy Resolves Multi-Year Patent Infringement Litigation With SMA").
• Tigo Energy Inc. v. SunSpec Alliance, No. 3:23-cv-00762-WHO (N.D. Cal.), filed 2023-02-21 — the induced-infringement order at Dkt. 36 addresses the '321 patent claims (and the '770). The '074 is absent.
• Tigo Energy Inc. v. Altenergy Power Systems / APsystems, No. 5:20-cv-03622 (N.D. Cal.) — reported as asserting the rapid-shutdown family ('321, '770). The '074 is absent.

One positive-but-not-litigation datapoint worth recording: Tigo's own Virtual Patent Marking page lists U.S. Patent No. 8,102,074 among the "Tigo-APsmart Licensed Patents" said to cover the APsmart RSD-S-PLC, RSD-S-PLC-B, RSD-D and RSD-D-15-1500 rapid-shutdown devices (https://www.tigoenergy.com/rsdvirtualmarking). That is a licensing/marking statement — the front end of an assertion program — not a filed case. It does, however, tell you the patent is being actively monetized rather than shelved, which is the relevant risk signal for a defendant.

⚠️ False positives — do not use these

The string "8102074" is a low-specificity numeric token and my searches surfaced several non-patent collisions. Explicitly excluded:

• A Colombian civil enforcement matter (GMAC Financial Colombia S.A. v. Jhon Fredy Bedoya Manjarres, Rad. 110014003048-2020-00679-00, Juzgado 48 Civil Municipal de Bogotá) — "8102074" is the defendant's cédula/ID number, not a patent.
• An FDA Adverse Event Reporting System (FAERS) case number 8102074 (Plan B One-Step / Teva, received 23-Aug-2011).
• A Brazilian municipal procurement act "Ato n.º 8102074" (Fundo Municipal de Saúde de Guabiruba) and a Rio Grande do Sul commercial registry entry for an unrelated company.
• A Chinese court filing "(2024)苏0214民初9474号" surfaced only because "8102074.6200" appeared in an unrelated financial table on the same page.
• IdeaHub Inc. v. Unified Patents, LLC, Fed. Cir. No. 2024-1684 (nonprecedential, Rule 36 judgment, April 10, 2026) — surfaced on the "unified patents" keyword, not the patent number. Unrelated (PGR2022-00044).

None of these is litigation involving US 8,102,074.

Caveats — verify before relying on this in a filing

1. Unified Patents litigation caselist and Docket Alarm were not directly queried at the case-record level. My retrievals were search-engine mediated; the Docket Alarm and Unified portal URLs I could reach returned docket documents for other cases, not a per-patent case list for 8102074. A direct pull of portal.unifiedpatents.com/litigation/ filtered on the patent, and of docketalarm.com by patent number, is still required to convert "not found" into "confirmed absent."
2. The 2026 docket sweep for the new owner is incomplete. The '074 was assigned to Tigo Energy Innovations LLC (Texas LLC), recorded 2026-01-20. I ran searches aimed at that entity as plaintiff and found no complaint. But a newly formed asserting vehicle's first suits would not necessarily be indexed under a search for "Tigo." Re-run a party-name sweep on PACER/CM-ECF for "Tigo Energy Innovations" across all districts and for all of 2026.
3. Do not conflate the '074 with its sibling US 8,272,172. They share the title and specification but have different claims. A case naming the '172 (US 13/357,331) is not a case naming the '074, and I found none naming the '172 either.
4. Date note. My environment's current date (2026-09-27) and the date stated in the task prompt (April 26, 2026) differ. Where I cite a source dated after April 2026, I have flagged it; the negative finding holds under either date as of the material retrieved.

What the absence means for you

Given the assignment analysis in this same file — the 2025-12-16 Patent Purchase Agreement transferring the portfolio to Tigo Energy Innovations LLC, whose stated business at PPA §6.2 is "licensing and/or asserting the Assigned Patents," with a §3.5 grant-back license to Tigo Energy, Inc. and a §3.4 no-contest covenant — 8,102,074 is best characterized as acquired-but-not-yet-asserted. The license/marking use of the '074 on the Tigo-APsmart rapid-shutdown page shows it is inside the monetization perimeter even though it has never been pleaded.

Recommended monitoring triggers: (a) any complaint by Tigo Energy Innovations LLC, (b) any IPR petition naming 8,102,074 (there is none — see the PTAB section), and (c) any demand letter referencing the Tigo-APsmart licensed-patent list. The patent's listed adjusted expiration is 2030-03-12, so the assertion window is roughly 3.5 years and closing — which, if anything, increases the probability of a near-term filing rather than decreasing it.

I'll verify the structured "no PTAB proceedings" result against public sources before writing up.

Let me dig deeper on any AIA trial naming this patent specifically, plus the related family member.

One more check on the third-party IPRs against Tigo patents and whether any reexam exists.

PTAB proceedings on file — US 8,102,074 B2

Sourcing note. The canonical list is the structured "PTAB proceedings on file" block: the USPTO Open Data Portal (ODP) API returns no AIA trial proceedings for this patent as of the most recent ingest. I verified that negative independently via web search against PTAB-generated documents (petitioner updated mandatory notices, board refund notices, district-court IPR status tables) and against the IP-verse PTAB case lists for both Tigo Energy and Altenergy Power Systems. Every hit ties to a different Tigo patent. Nothing in my searches surfaced an IPR, PGR, CBM, or ex parte reexam naming 8,102,074 or its continuation 8,274,172.

Proceedings overview

Total AIA trial proceedings on US 8,102,074: 0. Breakdown by status: 0 active, 0 claims invalidated, 0 claims sustained, 0 settled, 0 institution denied. Defensive posture for a defendant: the patent is entirely untested at the PTAB. No claim of 8,102,074 has ever been construed by the Board, no prior-art ground has been adjudicated, no third party is estopped, and the patent carries none of the narrowing that a survivable IPR usually imposes. That cuts both ways: there is no favorable FWD to point to, but also no adverse record, no Board claim construction to fight, and a clean slate for an invalidity theory — including an IPR filed the day after you are served.

No proceedings to report — what I checked instead

Because the standard per-proceeding template would be empty, here is the verification trail and the disambiguation that matters most, since Tigo is a serial PTAB litigant and its proceedings are easy to misattribute to this patent.

Verified absences:

• No IPR / PGR / CBM naming 8,102,074 in the ODP structured data, in PTAB E2E, or in any petitioner pleading I retrieved.
• No ex parte reexamination surfaced. (Weakest of the negatives — reexam records are less well indexed in the aggregators I could reach. A Reexam Certificate of Correction search in Patent Public Search would close this.)
• No Federal Circuit appeal arising from this patent. The CAFC activity in the Tigo family is the SunSpec appeal, and it is not about this patent — see below.

Statutory eligibility, for completeness:

Near-miss disambiguation — Tigo PTAB activity that is NOT this patent. These are the proceedings a careless search will wrongly attribute to 8,102,074:

None of these names 8,102,074. The SunSpec petitions' real parties in interest were identified as SunSpec Alliance, Fronius USA LLC, MidNite Solar, Inc., SMA Technology AG, Zerun Co., Ltd., and Zhejiang Jiaming Tianheyuan Photovoltaic Technology Co., Ltd. — none of which petitioned against this patent. Source for the SMA status table: Defendants' continued IPR status update, Tigo Energy Inc. v. SMA Solar Technology America LLC, No. 1:22-cv-00915-GBW (D. Del.), D.I. 118 (2024-02-21), available via Docket Alarm.

The one CAFC development in the family (context only, not this patent). SunSpec Alliance v. Tigo Energy, Inc., Fed. Cir. No. 2023-1741 — appeal from the IPR2021-01286 / -01287 final written decisions on the '321 and '770 patents. The nonprecedential opinion dated 2025-08-05 (https://www.cafc.uscourts.gov/opinions-orders/23-1741.OPINION.8-5-2025_2554121.pdf) addresses SunSpec's three claim-construction/obviousness arguments on the "predetermined number" of skips limitation and rejects each; the excerpted text contains no reversal. Caveat: I retrieved the opinion's reasoning rather than its final disposition line, so state it as "the panel rejected SunSpec's arguments" rather than quoting an "affirmed" decree. Either way, the '074 patent is not mentioned in that appeal because it was never in that IPR.

Strategic summary

Claim-by-claim status for 8,102,074. There is nothing to report because nothing has been adjudicated. Every claim stands exactly as granted on 2012-01-24: independent claims 1, 8 and 16, plus dependents 2–7, 9–15 and 17–19 (19 claims total). No claim is canceled, no claim has been narrowed by amendment, no claim has been construed by the Board. If a demand letter from Tigo Energy Innovations LLC cites claim 1's "single controller" plus two-LMU architecture, or claim 8's "predicted future voltage … and a maximum regulatory safety voltage," or claim 16's two-segment monitoring method, there is no PTAB ruling you can hold up to show any of those limitations have been read narrowly or held invalid. The claims are also entirely untested in any forum — the earlier litigation research found no district-court assertion either, so there is not even a Markman record to work from.

Estoppel landscape: clear. No IPR was ever filed, so § 315(e)(2) estoppel bars no one with respect to this patent. Two points follow. First, a defendant served today faces no restriction on the art it may raise — IPR, reexam, or district-court invalidity are all open, and there is no risk that an earlier petitioner's grounds were "reasonably could have been raised" and are now lost. Second, do not over-read the Altenergy and SunSpec proceedings: estoppel under § 315(e) is patent-specific, so Altenergy's settlement of IPR2021-00540/-00541 (on the '770 and '321 patents) and SunSpec's FWDs (on the same two patents) impose no constraint on grounds against the '074 patent. The § 315(b) one-year bar begins only when a complaint alleging infringement of this patent is served on the petitioner or its privies.

Pattern signals. Three things are worth flagging, and one of them is new information from the assignment research that a defendant should weigh carefully. (1) No repeat petitioner on this patent — because there has been no petitioner at all. Other Tigo patents attracted Altenergy (2021, two petitions, settled), SunSpec (2021, two petitions), and SMA (2023, three petitions); this one attracted none, which suggests it sits outside the SunSpec Rapid Shutdown Specification claim charting that drove the family's PTAB activity in 2021–2023. (2) Patent owner appellate posture: aggressive. Tigo litigated the SunSpec FWDs through to a Federal Circuit opinion rather than settling, and litigated the SMA matter to a 2026 district-court settlement, so its successor can be expected to defend any IPR vigorously rather than fold. (3) No defensive aggregator in the chain. The earlier assignment analysis found the chain terminates at Tigo Energy Innovations LLC, a newly-formed Texas LLC whose stated business the Patent Purchase Agreement itself describes as "licensing and/or asserting the Assigned Patents" — not RPX, Unified Patents, LOT, or OIN. Unified Patents was not a petitioner here. That matters strategically: this patent has not been neutralized, and there is no aggregator-funded challenge brewing that a defendant could free-ride on. The 2025-10-02 corrective assignment (Reel 58755 / Frame 0516) immediately preceding the 2025-12-16 sale reads as standing clean-up before assertion.

Cross-section flag. One discrepancy with the earlier-generated "Patent summary": that section lists Int. Cl. H04B 3/54 / USPC 307/5, while the authoritative full text in this prompt lists CPC H10F 77/955 (photovoltaic circuit arrangements) and Y02E 10/50. The classifications differ because they come from different vintages of the patent's face; the CPC set in the full text is the current one. This has no bearing on PTAB eligibility, which for a pre-AIA patent turns on filing date alone.

Recommended next steps

If you are a defendant (or counsel evaluating a demand from Tigo Energy Innovations LLC):

1. Say plainly in any pre-suit position paper that the patent has zero PTAB history. There is no FWD to cite, so do not represent otherwise. The accurate framing is: "No claim of U.S. 8,102,074 has ever been challenged, construed, or adjudicated."
2. Treat IPR as fully available and unconstrained. No § 315(b) clock, no § 315(e) estoppel, no Fintiv problem from a co-pending action on this patent (there is none), and no Sotera-style stipulation needed. If served, the one-year § 315(b) clock starts from service on you or your privies.
3. Check the '074 patent's own face before building a theory. Section 315(e) estoppel is irrelevant, but note that the granted claim 1 as printed does not recite "maximum regulatory safety voltage" or "predicted future voltage" — those limitations live in claims 8 and 19. Claim 19 depends from claim 18, which depends from the monitoring method; do not assume claim 19 is coextensive with claim 8. Any claim chart must use the granted text of this patent, not the continuation US 8,274,172, which carries a different claim 1 and is subject to a terminal disclaimer.
4. Do not rely on the '321/'770 PTAB record as a shortcut. A ground that failed against the '770 patent's "predetermined number of skips" limitation is not a ground against this patent's string-bus voltage-limiting claims, and the SunSpec FWD reasoning is not binding on a fresh panel.

If you want to close the remaining gaps:

• Reexam check: run a Reexamination Certificate search for 8,102,074 in USPTO Patent Public Search (https://ppubs.uspto.gov/) to convert my "no reexam found" from a search-artifact negative into a confirmed one.
• Docket watch: sweep D. Del., N.D. Cal., W.D. Tex., E.D. Tex. and the ITC for Tigo Energy Innovations LLC as plaintiff, using the exact strings 8102074 and 8,102,074. Given the 2025-12-16 transfer and the PPA's stated asserting purpose, any new complaint is the trigger event that would make a § 315(b) clock real.
• Articles of the new owner: pull the Texas SOS record for Tigo Energy Innovations LLC (registered agent, managers). The earlier analysis could not determine whether it is a captive Tigo vehicle or an independent purchaser; that answer changes nothing about PTAB availability but a great deal about settlement posture.

Primary links:

• PTAB E2E / Patent Trial and Appeal Board Center: https://ptacts.uspto.gov/ptacts/
• USPTO PTAB decisions: https://www.uspto.gov/patents/ptab/decisions
• Google Patents legal events for this patent: https://patents.google.com/patent/[US8102074B2](/patent/US8102074B2)/en
• CAFC No. 2023-1741 nonprecedential opinion (2025-08-05), SunSpec Alliance v. Tigo Energy, Inc. — different patents: https://www.cafc.uscourts.gov/opinions-orders/23-1741.OPINION.8-5-2025_2554121.pdf

Explicit uncertainties: (a) the "no PTAB activity" conclusion is a structured-data negative corroborated by search, and I did not query PTAB E2E's docket directly — I recommend a name/number query in PTAB E2E for 8102074 to make it airtight; (b) the ex parte reexam negative is the weakest link, as noted; (c) I have not verified whether the January 2026 transfer to Tigo Energy Innovations LLC included this specific patent in the PPA's Exhibit A-1 schedule, though the recorded per-patent assignment event supports it.

I'll research the assignment chain for US 8,102,074 against live sources before writing anything.

Critical find: a December 2025 patent purchase agreement. Let me verify whether the '074 is in the assigned patent schedule and nail down the earlier chain.

Assignment Record Analysis — US 8,102,074 B2

Method note / caveat up front: I was not able to query the USPTO Assignment Center's structured API directly in this session. The reel/frame and conveyance data below is drawn from (a) the legal-events block on the patent's own Google Patents record, (b) the SEC-filed Patent Purchase Agreement that produced the final assignment, and (c) Tigo's public licensing records. Where a reel/frame number was not retrievable, I say so rather than inventing one. Only one reel/frame number appears in the sources I could verify — Reel 58755 / Frame 0516 — and it appears because the 2025-10-02 corrective assignment cites it by number. Direct verification: USPTO Assignment Center · legacy search · Google Patents legal events.

Inventors

All three executed an assignment of assignors' interest to Tigo Energy, Inc., recorded contemporaneously with the 2009-09-18 filing. Hadar and Arditi are consistently identified in Tigo's PCT filings as Tigo's own listed inventors at Tigo's Los Gatos address (e.g., agent-of-record listing on WO 2010/062662 A3, assignee Tigo Energy, Inc., 170 Knowles Drive, Los Gatos, CA).

Unusual patterns: None found — and I want to be precise about what that means. I found no evidence of inventors departing and re-filing, no evidence of a separate inventor-owned entity, and no evidence of inventor-retained reversionary rights. I also could not independently verify the inventors' departure dates from Tigo, so I cannot affirmatively rule out a departure cluster. This is a case where the absence of a finding is weak evidence, not strong evidence. Note that this is the opposite of the classic pre-fire-sale tell (all inventors exit within 12 months): Hadar and Arditi are founder-level figures who remained associated with the company brand for years.

Original assignee

Tigo Energy, Inc. (Los Gatos, California; Delaware corporation) — named on the issued patent, and the assignee on the 2009-09-18 inventor assignment.

• Primary line of business: Module-Level Power Electronics (MLPE) — solar optimizers, rapid-shutdown devices, and monitoring hardware plus cloud software. The company is a practicing entity: it has shipped millions of MLPE units (Tigo's own disclosures state over 10 million MLPE devices shipped, installations in 100+ countries, ~2.3 GWh monitored daily).
• Does it ship products embodying the claims? Yes, and unusually directly: US 8,102,074 is itself listed on Tigo's public virtual patent-marking page as one of the licensed patents covering third-party rapid-shutdown devices — specifically the Tigo–APsmart licensed patents (alongside 7,602,080; 7,807,919; 7,884,278; 8,271,599; 8,274,172; 8,325,059; 8,933,321; and others), and it recurs across the QC Solar, GoodWe, MidNite Solar, Zerun, and Delta license groups. See e.g. https://tr.tigoenergy.com/rsdvirtualmarking and https://nl.tigoenergy.com/rsdvirtualmarking. That is meaningful: the '074 is not a dormant paper patent — it is an actively out-licensed asset covering competitor rapid-shutdown products.
• Current status: Operating, and publicly traded — NASDAQ: TYGO (IPO May 2023). Not acquired, not dissolved, not in bankruptcy. However, see the financial-stress note under Signal 6: the December 2025 patent divestiture was negotiated against a backdrop of thin net tangible book value and repayment of a convertible note.

Assignment timeline

Chronological, most recent first is not used — this is oldest-to-newest. All dates are execution/recording dates as surfaced; the patent's legal-events block does not separately distinguish execution from recording for the earlier entries.

2009-09-18 / recorded 2009-09-18 — Reel/frame not retrieved

• Conveyance: Assignment of assignors' interest (inventor-to-company)
• Assignor: Ron Hadar; Shmuel Arditi; Maxym Makhota (individually)
• Assignee: Tigo Energy, Inc.
• Correspondent: not retrievable from available sources
• Context: Ordinary inventor assignment at filing — the original corporate vesting.

2018-02-12 — Reel/frame not retrieved

• Conveyance: Security Interest
• Assignor: Tigo Energy, Inc.
• Assignee: Western Alliance Bank
• Correspondent: not retrievable
• Context: Securitization — a lender taking a blanket lien over the portfolio, not a transfer of ownership.

2020-03-27 — Reel/frame not retrieved

• Conveyance: Security Interest
• Assignor: Tigo Energy, Inc.
• Assignee: UMB Bank, National Association, as Trustee, and Newlight Capital, LLC
• Correspondent: not retrievable
• Context: Securitization — refinancing/replacement of the 2018 Western Alliance facility with a trustee-and-lender structure (Newlight Capital LLC first appears here).

2020-04-07 — Reel/frame not retrieved

• Conveyance: Release of Security Interest
• Assignor: Western Alliance Bank
• Assignee: Tigo Energy, Inc.
• Correspondent: not retrievable
• Context: Collateral release, consistent with the 2020 Newlight facility paying off and displacing Western Alliance.

2022-01-18 — Reel/frame not retrieved

• Conveyance: Assignment of Assignor's Interest
• Assignor: Tigo Energy, Inc.
• Assignee: Newlight Capital LLC
• Correspondent: not retrievable
• Context: This is the entry that needs the closest scrutiny. It is docketed as an assignment of interest rather than a security agreement, yet it sits between two security-interest entries and is followed by a 2023 release. Read in context it looks like a collateral or convertible-note-linked assignment rather than an outright sale — but the conveyance label as recorded says "assignment." I flag this as unresolved: an outright 2022 sale to Newlight that was somehow unwound in 2023 would be an unusual and significant fact; a collateral assignment that the USPTO indexed under the "assignment" subscriber is the more probable explanation. Verify the underlying document image before relying on either reading.

2023-02-22 — Reel/frame not retrieved

• Conveyance: Release of Security Interest
• Assignor: Newlight Capital LLC; UMB Bank, National Association
• Assignee: Tigo Energy, Inc.
• Correspondent: not retrievable
• Context: Lien release returning clean title to Tigo — consistent with repayment of the underlying facility.

2025-10-02 — Reel 58755 / Frame 0516 (cited as the corrected record)

• Conveyance: Corrective Assignment — "corrective assignment to correct the nature of conveyance previously recorded at Reel 58755, Frame 0516"
• Assignor: Tigo Energy, Inc.
• Assignee: Newlight Capital LLC
• Correspondent: not retrievable
• Context: Chain-cleaning. A corrective recording to Newlight, ~10 weeks before the portfolio sale closed. This is a meaningful sequencing signal: the Newlight lien/assignment record was being repaired in late 2025 so the patent could be conveyed free of encumbrances — which the purchase agreement expressly required (Sections 3.1 and 4.4: assignment "free and clear of any and all Encumbrances," with lien releases delivered at closing).

2026-01-20 — Reel/frame not retrieved

• Conveyance: Assignment of Assignor's Interest
• Assignor: Tigo Energy, Inc.
• Assignee: Tigo Energy Innovations LLC
• Correspondent: not retrievable
• Context: Transfer to a licensing/assertion vehicle. This is the recording that implements the Patent Purchase Agreement dated December 16, 2025 among Tigo Energy, Inc., Tigo Energy AI Ltd. (an Israeli company, formerly Foresight Energy Ltd.), as Seller, and Tigo Energy Innovations LLC, a Texas limited liability company, as Purchaser.

On the December 2025 transaction (the substance behind the final entry): aggregate purchase price $17,750,000–$17,950,000, of which $15,000,000 was paid at the initial closing; a $2,750,000–$2,950,000 holdback payable within four months; and up to $5,000,000 of royalties payable to the seller after closing. Seller received a non-exclusive, perpetual, irrevocable grant-back license to practice the assigned patents in its own products; Purchaser received an exclusive, worldwide, sublicensable license to the TIGO ENERGY trademark "solely in connection with the licensing and/or assertion of the Assigned Patents." The agreement also conveys causes of action and damages rights for past infringement and includes a "No Contest" covenant barring the seller from ever challenging validity. Tigo's May 2026 8-K confirmed the seller was paid the remaining $2,750,000 on May 14, 2026, with "net proceeds to the Seller… approximately $583,000, after the repayment of expenses."
Sources: Exhibit 10.1, SEC EDGAR · 8-K, Dec 17 2025 · May 2026 8-K · Tigo 424B5.

Important limit on this finding: the purchase agreement defines the "Assigned Tigo Patents" by reference to Exhibit A-1, which is redacted/not public. I could not directly confirm that US 8,102,074 appears on Exhibit A-1. The inference that it does is strong — the recording date (2026-01-20) trails the agreement's effective date by ~5 weeks, and the assignee matches the Purchaser exactly — but the exhibit itself is the evidence that matters. Treat "the '074 was sold in the December 2025 portfolio sale" as high-confidence inference, not documentary verification.

Timeline diagram

timeline
    title Ownership of US 8102074
    2009 : Inventors assign to Tigo Energy Inc
         : Application filed 18 Sep 2009
    2012 : Patent issued 24 Jan
    2018 : Security interest to Western Alliance Bank
    2020 : Security interest to Newlight and UMB
         : Western Alliance lien released
    2022 : Assignment of interest to Newlight Capital
    2023 : Newlight and UMB liens released
    2025 : Corrective assignment to Newlight at 58755 0516
         : Portfolio sold to Tigo Energy Innovations LLC
    2026 : Final assignment recorded 20 Jan

NPE / troll-pattern signals

1. Shell-entity transfer — present

The patent has moved from a practicing operating company (Tigo Energy, Inc., which ships MLPE hardware) to Tigo Energy Innovations LLC, a Texas limited liability company with no products, formed for the transaction, and acquiring the portfolio for cash. The agreement makes the entity's purpose explicit rather than implicit: the Purchaser takes an exclusive trademark license to use "TIGO ENERGY" solely in connection with "the licensing and/or assertion of the Assigned Patents." An entity whose only licensed use of a brand is assertion is, by the agreement's own terms, an assertion vehicle. Evidence: assignment of assignor's interest recorded 2026-01-20, implementing the agreement effective 2025-12-16.
Caveat that cuts against a clean "shell" call: the LLC shares branding, personnel lineage, and economics with the seller (seller retains royalties and a grant-back license). It is a related-party vehicle, not an anonymous arm's-length purchaser. The "single-purpose Delaware or Texas LLC with no products" tell is satisfied; the "designed to look unrelated" tell is not.

2. Known asserter in the chain — not present

I compared the chain against the standard NPE roll (Acacia/ACT, Marathon Patent Group, Intellectual Ventures, IPNav, Wi-LAN, Mosaid/Conversant, Vringo, Pendrell, Innovatio IP Ventures, MPHJ, Lumen View, Round Rock Research, Document Generation Corp, Spangenberg entities). No match. Newlight Capital LLC is a secured lender, not an asserter — it enters the chain on 2020-03-27 as a secured party alongside UMB Bank as trustee, and releases on 2023-02-22. Critically, note the data-hygiene trap: Unified Patents' portal shows "Newlight Capital LLC" as "Parent Company / Current Assignee" on a wide swath of Tigo patents (e.g., US-20110304215-A1, US-7884278-B2, US-20110173276-A1). That is an artifact of the same blanket security-interest recording, not evidence that Newlight holds title. Do not cite those aggregator pages as proof of a Newlight NPE. Tigo Energy Innovations LLC does not appear on any RPX or Unified high-frequency-plaintiff list that I could surface.

3. Repeat correspondent across the chain — unclear

This is the signal I most wanted and could least verify. The correspondent-of-record fields were not retrievable from any source I could reach; the Google Patents legal-events block exposes assignor/assignee/conveyance but not the recording correspondent. The only attorney name I surfaced anywhere in this family is John P. Ward, listed as agent on Tigo's related PCT (WO 2010/062662 A3) — but that is prosecution-side, on a different application, and proving nothing about who recorded the assignments. I am not going to name him as the chain's recording correspondent. Action item: pull the correspondent fields for all eight recordings directly from the Assignment Center; if the same firm appears on the 2022 Newlight assignment, the 2025 corrective assignment, and the 2026 Innovations assignment, that recurrence is the finding — and it would be the single most probative item in this entire analysis.

4. Cascading transfers — not present, with a timing flag

The genuine successive third-party transfers are 2022-01-18 (to Newlight Capital) and 2026-01-20 (to Tigo Energy Innovations LLC) — roughly four years apart, with a release in between returning title to Tigo. That is not a <24-month cascade. However, there is a dense 2025–2026 cluster: a corrective assignment on 2025-10-02, the sale agreement effective 2025-12-16, and the implementing recording 2026-01-20 — three ownership-related events in under four months. The corrective assignment to Newlight ~10 weeks pre-closing reads as pre-sale chain-cleaning, which is a standard step in a patent portfolio sale and is not itself an NPE tell.

5. Pre-litigation transfer — present as structural risk, not as an event

There is still no suit I can identify asserting the '074 (consistent with the litigation section of this analysis). So a transfer-within-6-months-before-a-first-suit does not yet exist as a fact. But note the structure: the purchase agreement expressly conveys past-infringement causes of action and the right to collect damages, bars the seller from contesting validity, and takes an exclusive mark license for assertion. That is the full toolkit for a sequencing-to-suit, assembled in December 2025. I am flagging the capability and intent, not asserting a filed case, because I have no evidence of one.

6. Bankruptcy fire-sale — not present

Tigo Energy, Inc. is a NASDAQ-listed operating company (TYGO); the patent transfer was a negotiated asset sale, not a Chapter 7/11 disposition. The proceeds were applied to repay a convertible note in full (per the 424B5) — a liquidity and deleveraging transaction. However, I would not describe the seller's financial condition as comfortable: the same 424B5 discloses that, after giving effect to the patent sale, the convertible-note repayment, and a 5,000,000-share offering at $3.00, pro forma as-adjusted net tangible book value as of 2025-09-30 would have been approximately $22,766,000, or $0.31 per share. That is a motivated seller. A motivated seller with deep IP and no other financing options is exactly the profile that precedes more portfolio sales — worth monitoring, but it is not a bankruptcy fire-sale on these facts.

7. Privateering — present (strongest signal)

This is the clearest, best-documented finding in the entire chain, because the terms are in an SEC-filed agreement:

• Operating company sells patents to a licensing-only affiliate;
• Seller keeps a grant-back license to keep practicing the patents in its products;
• Seller keeps up to $5,000,000 of royalty upside — i.e., it participates in the new owner's licensing revenue;
• Purchaser gets an exclusive TIGO ENERGY trademark license "solely in connection with the licensing and/or assertion" of the patents — effectively loaning the operating company's brand to the assertion campaign;
• "No Contest" covenant bars the seller from ever challenging validity;
• "Excluded Entity" / anti-immunization provisions expressly bar the seller from using its grant-back license "for the purpose of immunizing the products of any Excluded Entity from claims of infringement" — language whose only function is to protect a third-party enforcement campaign against named competitor targets.

That last provision is the tell. Traditional patent sales do not need to police whether the seller is helping third parties avoid the buyer's claims.

8. Defensive aggregator (anti-NPE) — not present

The chain terminates at Tigo Energy Innovations LLC, a monetization vehicle. It does not terminate at RPX, Allied Security Trust, LOT Network, Unified Patents, or the Open Invention Network. The patent has not been neutralized. Note the inverse datapoint: SunSpec Alliance's IPR campaign against sibling Tigo patents ('321, '770) is the closest thing to coordinated defensive action in this family, and it targeted other patents — not the '074.

Verdict

NPE — high confidence.

Two strong, independently documented signals drive this: (1) a shell-entity transfer — US 8,102,074 moved from practicing operating company Tigo Energy, Inc. to Tigo Energy Innovations LLC, a Texas LLC with no products, by an assignment of assignor's interest recorded 2026-01-20 under the December 16, 2025 Patent Purchase Agreement, whose grant to the buyer of an exclusive TIGO ENERGY trademark license "solely in connection with the licensing and/or assertion" of the patents removes any ambiguity about the entity's function; and (2) privateering — the seller retained a grant-back license, up to $5,000,000 in royalties, a No Contest covenant, and an anti-immunization/"Excluded Entity" clause, which is the signature of an operating company outsourcing enforcement while keeping the economics. Note the difference from a classic troll chain: this vehicle has never been used to sue on this patent, the seller and buyer are related parties, and the seller's own products practice the claims under the grant-back license — so the pattern is high-confidence while litigation risk attributable to the '074 specifically remains unproven.

Two things I could not verify and would not want relied upon: (a) whether US 8,102,074 is listed on Exhibit A-1 ("Scheduled Tigo Patents") — the exhibit is not public, so the transfer is a strong inference from matching dates and assignee, not a documentary confirmation; and (b) the correspondent of record on every recording. The only reel/frame I could confirm is Reel 58755 / Frame 0516, and only because the 2025-10-02 corrective assignment cites it by number. Pull the correspondent fields from the Assignment Center for all eight recordings — recurrence of a single attorney across the 2022 Newlight assignment, the 2025 correction, and the 2026 Innovations assignment would convert Signal 3 from unclear to present and would materially strengthen the picture.

I'll pull the actual "References Cited" data for this patent rather than rely on memory, since the authoritative text block I was given does not reproduce the citation list.

Let me pull the front-page citation list directly from the granted patent document.

Prior-art analysis — US 8,102,074 B2

0. A threshold problem I have to flag before anything else

I could not retrieve the patent's own front-page "(56) References Cited" list. The authoritative patent text block supplied to me for this analysis (the Google Patents fetch at https://patents.google.com/patent/US8102074/en) does not reproduce the citations section — it jumps from the abstract/description into the claims. It contains a "Prior art keywords" line (voltage; string bus; solar module; controller; lmu) but no list of cited U.S. patents, cited foreign documents, or cited non-patent literature.

I then ran targeted retrieval against patentimages (the scanned/published front page), uspto.report, FreePatentsOnline, and Google Patents' citation tab. What came back was consistently the citation list of other patents that cite the '074 — not the '074's own reference list. Every FreePatentsOnline "US Patent References" block I surfaced belonged to a different patent ('172, '246, '825, '488, '916, '738, '558, '1228) and merely lists the '074 among its references.

I am therefore not going to present a fabricated table of "each patent citation for 8102074." Under my operating rules I must say so explicitly rather than invent reel-accurate citations. What follows is (a) the citation data I did verify, (b) a clearly-labelled best-effort identification of the prior art that matters, and (c) the exact verification steps needed to convert this into a citable reference list.

1. What I did verify: the forward-citation landscape

These are the verified, self-consistent finding of this session — the patents and publications whose own reference lists cite US 8,102,074 (19 U.S. patents plus several foreign family members). This is the mirror image of the request, but it is real, sourced data and it is directly useful for claim-context and for locating the art that did get cited in this family's prosecutions.

Sources: FreePatentsOnline pages for the above grants (e.g. https://FreePatentsOnline.com/[8274172](/patent/8274172).html, https://FreePatentsOnline.com/[8860246](/patent/8860246).html, https://www.freepatentsonline.com/[9431825](/patent/9431825).html); Google Patents "cited by" panels at https://patents.google.com/patent/JP5498388B2/en and https://patents.google.com/patent/CN103155349A/en.

Note the direction of inference: none of these is § 102 prior art against the '074. They post-date it. Do not let anyone map them onto the claims as anticipatory art.

2. The prior art that actually matters — best-effort identification

Below is the art I can identify from this patent family's own prosecution and litigation record, mapped onto the '074's claims. Label each item "not verified as appearing on the '074's face" until you pull the front page. I have marked my confidence on each.

2.1 The family's litigated art (SunSpec / SMA IPRs)

The SunSpec Alliance IPRs against Tigo family members put a defined prior-art cluster on the record. From the IPR2021-01287 (US 10,256,770) petition grounds:

Source for the ground listing: IPR2021-01287 papers, Docket Alarm (https://www.docketalarm.com/cases/[PTAB](/ptab)/IPR2021-01287/SunSpec_Alliance_v._Tigo_Energy_Inc/). Also Dunton declaration and Moine/Kronberg documents in IPR2021-00541 (https://www.docketalarm.com/cases/PTAB/IPR2021-00541/Altenergy_Power_Systems_Inc._v._Tigo_Energy_Inc/).

2.2 References from the sibling's PCT search report (prosecution history)

The prosecution history of US 10,256,770 (submitted as Exhibit 1004 in IPR2021-01287) reproduces a PCT search report for PCT/US2011/033658 (filed 2011-04-22, priority 2010-04-22) that categorises:

Critical timing problem for two of these: US 2009/0207543 (2009-08-20) and US 2009/0179662 (~2009-07-16) published after the '074's 2009-07-30 priority date. Under pre-AIA § 102 they are not § 102(a)/(b) art against the '074's claims on that priority date (they could only be § 102(e) art if their U.S. filing dates predate 2009-07-30 — a separate check). The '074, filed 2009-09-18 claiming provisional 61/273,210 of 2009-07-30, is pre-AIA (pre-2013-03-16), so § 102(a)/(b)/(e) all apply. Do not assume the sibling's cited art transfers as § 102 art.

3. Claim-by-claim § 102 mapping (framework, with honest confidence levels)

Because I do not have the '074's own citation list, I am mapping the identified art against claim scope rather than reporting an examiner's rejection. Claim numbering is the granted numbering: 1, 8, 16 are independent; 19 claims total.

Claim 1 — single controller + first and second LMUs

string bus; first and second solar modules each generating a voltage; a single controller configured to limit at least one of the first and second voltages provided to the bus; a first LMU coupled between the first module and the bus and in communication with the single controller; a second LMU coupled between the second module and the bus and in communication with the single controller.

Potential § 102 art:

• Adest US 2008/0164706 A1 (2008-07-10) — likely the closest single-reference candidate if it discloses a central controller communicating with per-module converters. The distributed-architecture references in this cluster typically disclose module-level converters with an central control/communication element; the "single controller" + "each LMU in communication with the single controller" limitation is the crux. Moderate confidence at best — a § 102 rejection on this claim requires the reference to disclose both LMUs being in communication with one shared controller, which distributed-architecture art often does not state cleanly.
• Formge US 2009/0066357 A1 (2009-03-12) — cited category X on the sibling's claims 1–5, 15–18. Given the X categorization on a structurally similar apparatus claim, this is the single most likely § 102 candidate on the '074's claim 1 — but I have not read its disclosure and will not assert an element-by-element match. Verify first.
• Tigo's own US 7,602,080 (Hadar, 2009-10-13) — likely a § 102(e)/self-collision candidate if cited; a same-assignee earlier application is not automatically disqualified under § 102(e), but it can be sworn behind under § 1.131 or § 1.132. Flagged as a possibility only.

Claim 8 — control based on predicted future voltage + maximum regulatory safety voltage

controller configured to control the voltage provided to the bus based on a predicted future voltage as predicted by the controller and a maximum regulatory safety voltage.

This is the hardest claim in the patent to anticipate. I found no reference in the identified cluster that discloses control keyed to a forecast voltage (the spec's own §-defining passage is "an estimated voltage existing at a particular future time," with a five-minute horizon) combined with a regulatory ceiling. § 102 anticipation of claim 8 would need a single reference disclosing both.

• Adest 2008/0164706 / Adest '055 / Adest '178 — these disclose reactive, measurement-driven module control and disconnection, not predictive forecasting. They are § 103 candidates, not clean § 102 art, for claim 8.
• Moine FR 2 894 401 A1 — an energy-management device. No prediction limitation expected.
• Kronberg US 5,054,023 (1991) — an old switching/converter reference; a prediction limitation is implausible.
• Realistic § 102 exposure for claim 8 is low. Where I would look instead: PV monitoring/SCADA art (irradiance-and-temperature forecasting feeding a string-voltage cap), which is not in the identified cluster.

Claim 16 — two-segment monitoring + limiting on regulatory ceiling

monitoring a first voltage across a first string-bus section connecting first module to second module; monitoring a second voltage across a second string-bus section connecting the second module to a voltage output; limiting the voltage output based on a maximum regulatory safety voltage by limiting the voltage of at least one of the first and second solar modules.

Potential § 102 art:

• Adest US 2008/0164706 A1 — if it discloses sensing bus voltage at more than one point and throttling a module to cap overall string voltage. Reasonable candidate; not verified.
• Moine FR 2 894 401 A1 — an energy-management device for a series-string installation could disclose multi-point sensing; not verified.
• Formge US 2009/0066357 A1 — carries the X categorisation against sibling claims 1–5 and 15–18, and claim 15–18 in the sibling corresponds to a method/apparatus claim set structurally close to the '074's method arm. This makes Formge the highest-value single reference to read first.

Dependent claims of interest

• Claim 3 ("the controller comprises: a first LMU … a second LMU") is the opposite architecture to claim 1 (distributed controller rather than single controller). Art that discloses distributed module controllers — the Adest cluster, Wolfs US 8,093,757 (2012-01-10), Tigo's own US 7,602,080 — maps onto claim 3 far more naturally than onto claim 1. Do not use the same reference to argue both; the claims are mutually reinforcing rather than redundant.
• Claim 6 (duty-cycle and phase parameter on the transistor of the first LMU; duty cycle on the second) is narrow and specific; the spec's own §"switches in different LMU's can operate at different phases" passage is the pivot. Phase-offset PWM across module converters is the subject of Tigo's own US 7,602,080-era work — check for self-collision.
• Claim 12 ("predicted future voltage is based on a voltage trend") narrows claim 8; claim 19 mirrors it on the method side. No art identified in this session discloses trend-based prediction.

4. What is genuinely missing, and how to close it

The specific artifacts that would convert this framework into a citable table:

1. The '074's front-page (56) block — pull from the granted PDF's face (patentimages storage link for US8102074) or PatentCenter's "Patent Full-Text" → References Cited. This is the single missing input for the task as posed.
2. The examiner's citations and their § 102/§ 103 categorisations — from the file wrapper on PatentCenter (application 12/562,933). This tells you which references were applied against which claims, not merely listed.
3. The Information Disclosure Statements — to separate applicant-submitted art from examiner-applied art.
4. Formge US 2009/0066357 A1 full text — highest priority read, given its X categorisation against the structurally similar sibling claims 1–5 and 15–18.
5. The Adest '055 and '178 full identities — resolve the ground labels from IPR2021-01287 Paper 2 (petition) before citing; I could not resolve them here.
6. Moine FR 2 894 401 A1 and Kronberg US 5,054,023 full texts — confirm dates and check for the "regulatory maximum voltage" limitation, which is the concept most likely to be absent.

5. Explicit uncertainties — do not let these be smoothed over downstream

• I did not obtain the '074's own reference list. Everything in § 2 and § 3 is derived from the family's prosecution/litigation record and from the forward-citation landscape, not from the patent's face. The task's requested format — "for each patent citation for 8102074 … which claim(s) it potentially anticipates under § 102" — cannot be completed as literally posed from what I retrieved.
• I have not verified the technical disclosure of Formge, Boniface, Mollton, Moine, or Kronberg. Their citations, dates, categories and claim mappings are taken from retrieved records; their content is not. Do not quote them as disclosing anything I have not read.
• Pre-AIA § 102 governs. The application was filed 2009-09-18 (priority 2009-07-30), before the 2013-03-16 AIA date. "Prior art" means § 102(a)/(b)/(e) art. Two of the sibling's cited references publish after the '074's priority date and therefore do not qualify under § 102(a)/(b).
• Do not conflate the '074 with US 8,274,172 or US 2012/0119584. Same title, same specification, different claims. The sibling's X-categorised reference (Formge) was applied against the sibling's claims 1–5 and 15–18; that mapping is evidence about Formge, not a finding about the '074's claims.
• No AIA trial has ever been filed against the '074 (see the PTAB section of this file). Consequently there is no Board or court construction of "single controller," "local management unit," or "predicted future voltage" to lean on, and no institution record in which the '074's cited art was tested. Whatever § 102 position you build will be first-principles.
• Date note: my environment's date and the task-prompt date differ (2026-09-27 vs. 2026-04-26). Sources dated after April 2026 are flagged where cited; the substantive findings do not turn on the difference.

Verify at: https://patents.google.com/patent/US8102074/en (Patent Citations tab), https://patentcenter.uspto.gov/ (application 12/562,933, References Cited + file wrapper), and the granted-PDF front page for the Examiner's secondary reference tags.

I'll ground this analysis in whatever prior art I can verify for this specific patent's family before writing anything.

Let me pull the full front-page reference list and locate the key family-art references.

I have the front-page reference list (partially). Let me characterize the key references before analysis.

Obviousness Analysis — U.S. Patent No. 8,102,074 B2 under 35 U.S.C. § 103

0. Provenance and two threshold flags

Flag 1 — there is no "Prior Art section" in the material supplied to me. The full patent text I was given is the Google Patents rendering of US 8,102,074 (front matter, description, abstract, claims 1–16). It contains no "Prior Art," "References Cited," or "Cited By" section, and the rendering of claim 16 is truncated mid-sentence. The previously generated sections in this file cover the patent summary, litigation, PTAB, and assignments — none of them is a prior-art section either.

Rather than invent a prior-art record, I reconstructed one from two sources I could actually retrieve:

1. The (56) References Cited block on the front page of the '074 itself (US 8,102,074 PDF, page 1: https://patentimages.storage.googleapis.com/08/f0/2a/d8aea7cc33c70c/US8102074.pdf). I retrieved it partially — the U.S. patent list is largely visible but truncated, and the Foreign Patent Documents, "Other Publications," and Primary Examiner fields were not retrieved at all. Treat the list below as incomplete.
2. The prior art of record in this family's IPRs — the SunSpec petitions' exhibit lists (Ex-1005 FR2894401A1 to Moine; Ex-1006 US 5,054,023 to Kronberg; Ex-1007 US 8,531,055 to Adest; Ex-1008 US 9,088,178 to Adest), retrieved from the IPR2021-01286 and IPR2021-01287 file records.

Everything else in this section — my characterization of what a reference discloses, and my knowledge of Solaredge/Wolfs/Ledenev content — is drawn from training data and is flagged as such; it must be verified against the reference texts before it goes into an invalidity contention.

Flag 2 — date. The task states April 26, 2026. The environment states 2026-09-27. The prior sections in this file already flagged this discrepancy. It does not change the analysis, but note that several of the assignment and 8-K facts in the earlier sections are dated after April 2026.

One more caveat that matters legally, not just rhetorically: the '074's prosecution history was not available to me. I cannot tell from the face of the patent which of the cited references the examiner actually applied in a §103 rejection, what arguments were made, or what was amended. Any conclusion about "what the applicant gave up" is provisional.

1. Framework

Governing law: Graham v. John Deere Co., 383 U.S. 1 (1966); KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007). Because the application was filed September 18, 2009 and claims priority to July 30, 2009, pre-AIA § 103 applies, including pre-AIA § 103(c)(1) — which becomes decisive here, because most of the closest art is the applicant's own (see §8).

Level of ordinary skill. No tribunal has set a POSITA level for the '074. The Board took POSITA evidence in the sibling IPRs (Dr. Balog for Tigo; Dr. Dunton for SunSpec), but that record belongs to the '321/'770, not the '074. My proposed level, which is a construction, not a finding: a bachelor's degree in electrical engineering (or equivalent) plus two to four years of experience in power electronics, DC-DC converter design/control, or photovoltaic system design. The subject matter is mature, well-documented engineering; the skill level should be set relatively high, which helps an obviousness case.

Claim construction — no term in this patent has ever been construed by any tribunal. The load-bearing terms, with the specification's own definitions (which will control):

Practical consequence of the construction table: the specification defines its own terms broadly and defines the goal as merely "limiting a portion of the voltage that each solar module provides to the string bus." That self-definition is the single biggest vulnerability in the patent.

2. The subject matter of the claims, decomposed

Claim 1 (independent, system) — four elements:

• (a) a string bus;
• (b) first and second solar modules connected to the bus, each generating its own voltage;
• (c) a single controller configured to limit at least one of those voltages as provided to the bus;
• (d) first and second LMUs, each coupled between its module and the bus, and each in communication with that single controller.

Notably absent from claim 1: any regulatory ceiling, any prediction, any trend, any switchable connection, any transistor, any duty cycle. Claim 1 is an architecture claim, and it is the broadest and weakest claim in the patent.

Claim 8 (independent, system) — string bus + solar module + controller "configured to control the voltage provided to the string bus based on a predicted future voltage as predicted by the controller and a maximum regulatory safety voltage."

Claim 16 (independent, method) — monitor V₁ across a first bus section (module 1 → module 2); monitor V₂ across a second bus section (module 2 → output); limit the output "by limiting at least one of a voltage of the first solar module and a voltage of the second solar module."

⚠️ I could not read claim 16's full text. The Google Patents rendering truncates at "monitoring a first voltage across a first st…". The rendition I use here is from the previous section, which took it from uspto.report. Claims 17–19 are likewise unverified. Any charting of 16–19 must be redone against the granted text.

3. The reference set

3a. References on the face of the '074 (partially retrieved)

From the (56) block: US 4,580,090 (Bailey, Maximum power tracker); US 4,604,567 (Chety); US 4,873,480 (Lafferty); US 5,027,051 (Lafferty); US 5,504,418 (Ashley); US 7,248,946 (Bashaw); US 7,256,566 (Bhavaraju, determining a maximum power point of photovoltaic cells); US 7,259,474 (Blanc); US 7,276,886 (Kinder); US 7,336,004 (Lai); US 7,378,820; US 7,394,737; US 7,462,955 (McNamara); US 7,518,266 (Eckroad); US 7,518,346 (Prexl); US 7,538,451; US 7,545,053; US 7,560,906; US 7,595,616 (Prexl); US 7,602,080 (Hadar et al. — Tigo's own); US 7,605,498 (Ledenev et al.); US 7,719,140 (Ledenev); US 7,839,022 (Wolfs); US 7,902,361 (Adest). Publications: 2005/0057214, 2005/0112995, 2006/0001406, 2006/0174939, 2006/0185777, 2007/027333 (all Matan); 2005/0057215 (Rohrig); 2007/0019613 (Frezzolini); 2008/0030305 (O'Connor); 2008/0094640 (Garner); 2008/0097655 (Hadar et al.); 2008/0106241 (Deaver); 2008/0121272 (Besser); 2008/0122… (truncated).

3b. References of record in the family IPRs

3c. What I verified about the single most important reference

US 2008/0097655 A1 (Hadar & Davis) — I retrieved its abstract, claims, and description. Verbatim disclosures:

• Claim 1: "a management unit to be interconnected via a network bus to a set of link modules, each link module coupled to a separate local energy production unit, each link module to include a Maximum Power Point Tracking (MPPT) step-up converter and a parameter monitoring unit to produce parameter data for the respective local energy production unit… and the management unit to receive measured parameters from the link modules, and to send control signals to link modules to provide individual operational control of the local energy production units."
• Claim 8: parameter data "comprises one or more of current, voltage, temperature, and panel identification code."
• Claim 9: "the management unit is to transmit power-on and power-off signals to the link modules via the network high voltage bus to power-on and power-off individual local energy production units."
• Description: "All panels 101a-n provide power to a common Network/High Voltage Bus 102… The bus feeds the produced electrical energy to a consumer of the energy, in this case grid-tied inverter 103." And: "Means to enable/disable panels, inverter, battery units, and other energy producing equipment in the system are implemented… website 107 will interact with management unit 104 and that will in turn control the panels."

Mapping that onto claim 1 — this is close to a complete anticipation, and certainly a devastating §103 reference:

Status as prior art: published April 24, 2008, more than one year before the July 30, 2009 provisional → § 102(b) art, which means it survives the § 103(c) common-ownership disqualification (§ 103(c) applies only to art that qualifies solely under 102(e)/(f)/(g)). This is the key structural point of this whole analysis — see §8.

4. Combination A — Claim 1

Primary: Hadar '655 (US 2008/0097655 A1). Secondaries: Wolfs '503/'022; Prexl '346/'616; Ledenev '498/'140.

What the secondaries add. Wolfs discloses a per-solar-generator (or per-cell, one-to-nine cells) buck-type DC-DC converter operatively associated with each solar generator, with the trackers connected in series and each controlled to its own maximum power point — i.e., a per-module converter whose output voltage contribution to a series string is set by a control loop, and a demonstration that series-stacked module converters are the way to build string voltage. (My characterization of Wolfs is from general knowledge of this well-known reference; I did not re-read its text in this session.) Prexl adds closed-loop buck-boost control of converter output. Ledenev adds "boundary controlled" conversion. Adest '055/'178 is an equivalent-to-Wolfs alternative: per-module DC-DC converters under a central controller communicating over the power conductors — and it is the one reference in this set whose claim-level disclosure the Board has actually tested, in the '770 IPR.

Why a POSITA would combine. Under KSR, a combination is obvious where it is "the combination of familiar elements according to known methods … yield[ing] predictable results." Here:

1. The problem was the art's own. The '074's background itself recites the constraint: "the voltage on any part of the power line connecting solar modules into a solar array should not exceed 600V… In Europe this limit is 1000V," and that conventional arrays run "well below … limits." A specification's statement of the problem is an admission that the problem was known; it supplies the motivation element directly rather than requiring the challenger to prove it.
2. To build a long series string while respecting a fixed voltage ceiling, the number of options was small and finite. Either (i) use fewer modules (the prior-art expedient, at a direct power cost) or (ii) actively control each module's voltage contribution so the summed bus voltage stays under the ceiling. KSR's "finite number of identified, predictable solutions" and "obvious to try" rationales apply.
3. No new hardware was required. Hadar '655 already puts a controllable converter + monitor + control channel at every panel; Wolfs already puts a series-connected buck at every panel. Once a converter is at the module and the module's voltage can be commanded, holding that converter's output at less than its MPP voltage when the string total would breach the ceiling is a set-point change to an existing control loop — the paradigm KSR case of a predictable result from a known technique.
4. No change in principal operation, no loss of the references' own purposes. Hadar '655 retains per-panel monitoring and control; Wolfs retains per-generator MPPT (the module still operates at its own MPP input; only the output set-point is capped — exactly the architecture Tigo itself later marketed, see §9).
5. The control channel already existed. Both Hadar '655 and Adest teach that commands travel on the power conductor itself, which is precisely claim 1's "in communication with the single controller" and the '074's own FIG. 6/7 teaching that "the command to control the operation of the switch Q1 606 is sent to the LMU 602 over the photovoltaic (PV) string bus (power line) 610."

Claim-by-claim result — Combination A: Claim 1 obvious; on my reading of Hadar '655 it is arguably anticipated, with "limit" supplied by claim 9's per-panel power-on/power-off (see the '074's own definition of "limit," §1). If the patentee successfully argues that "limit" requires modulated reduction rather than on/off, Wolfs/Prexl/Ledenev supply the modulated reduction as an obvious substitution.

5. Combination B — Claim 8 (prediction + regulatory ceiling)

Claim 8 adds two limitations to the architecture of claim 1. Each is separately vulnerable.

(i) "a maximum regulatory safety voltage"

This is a published regulation, not an invention. The applicable U.S. provisions are in the National Electrical Code, Article 690 (Solar Photovoltaic Systems) — and the '074's own specification recites the numbers. A POSITA designing a string in 2008–2009 had no discretion here: the ceiling exists in the code, is fixed, and is documented. A limitation whose content is "obey a known published standard" cannot supply patentable weight on its own. Art supporting the concept of limiting module voltage to a ceiling: Takehara US 6,331,670 (Solar cell module having an overvoltage preventive element and sunlight power generation system using the solar cell module) and Kurokami US 5,923,158 (Power control apparatus for solar power generation system). ⚠️ I could not confirm from the truncated (56) block whether Takehara '670 was cited on the '074's own face; it appears in the reference lists of sibling Tigo patents (e.g., US 8,415,552), so it is family-adjacent art rather than confirmed-cited art.

(ii) "predicted future voltage as predicted by the controller"

This is the genuinely non-trivial limitation, and it is where the §103 case is weakest — but still sustainable on the art of record:

• Besser (US 2008/0121272 and the "power extractor detecting power and voltage changes" / "power extractor with control loop" family) appears in the '074's own (56) block. A control loop that detects changes in voltage and power and adjusts on that basis is, at minimum, a controller deriving its next state from the history of measured values — the functional equivalent of a trend. ⚠️ I did not read the Besser texts; a full-text pull is required before this is usable.
• MPPT by definition predicts a future operating point from past samples. Perturb-and-observe and incremental-conductance compute the sign of the derivative from prior measurements and command a next operating voltage. The '074's own face cites Bhavaraju US 7,256,566 ("determining a maximum power point of photovoltaic cells"), Bashaw US 7,248,946, and (in the sibling lists) Kasai US 6,844,739 ("Maximum power point tracking method and device"). If a converter is already computing a future target voltage from a series of past voltage/current samples, the claim-8 requirement of controlling based on a "predicted future voltage" is met by the ordinary operation of the converter that Combination A already places on every module.
• Protective-relay practice. Anticipatory protection — acting on a rate-of-rise or trend before a limit is crossed, rather than after — is standard power-systems engineering. The '074's own spec confirms the motivation: the system is meant to hold the array as close to the limit as possible, and reactive-only limiting causes the array to oscillate across the limit; that oscillation is the articulated engineering reason to predict. The spec's fallback language ("if the controller monitors a certain rate of change it may trigger commands… to fall back to the default voltage") is itself a trend-based control.
• Cold-temperature Voc rise is the textbook motivating example and is expressly recited in the '074's background as a known phenomenon ("cold temperatures increase solar cell efficiency and thus voltage output"). Controlling the output voltage so that the module's contribution is temperature-independent is the direct, predictable response — and the reason the ceiling might be breached at all.

Combination B: Hadar '655 (architecture) + Bhavaraju '566 / Kasai '739 (deriving a future target from a measured trend) + Takehara '670 or Kurokami '158 (module-level voltage-ceiling enforcement), motivated by the known regulatory ceiling and the known temperature/Voc-rise problem. Result: claim 8 obvious. This is the harder claim, and the prediction element is where a patent owner would fight.

6. Combination C — Claim 16 (sectioned bus monitoring + limiting)

Hadar '655 + Moine FR2894401A1 or Adest '055/'178 + Takehara '670 ('670 or Kurokami '158).

Claim 16's distinctive element is monitoring two separate bus sections — one between module 1 and module 2, one between module 2 and the output — and then limiting.

• Hadar '655 supplies per-unit voltage and current telemetry to a single management unit (claim 8 of '655: current, voltage, temperature, panel ID). With per-module voltages reported to one master, the voltage across any bus section — the running sum of the contributions upstream of that section — is available at the controller by simple summation. The '074's own specification states exactly this arithmetic: "the voltage on a segment … between any two solar modules … is equal to the sum of the voltage contributions from each solar module that came before that segment."
• Moine and Adest supply central control of a series string of per-module converters.
• Takehara '670 / Kurokami '158 supply module-level enforcement of a voltage ceiling.

Motivation (this one is strong and articulable): you cannot decide which module's contribution to throttle unless you know where on the string the excess arises. In a series string the bus voltage is monotonically increasing toward the output, so the sections nearest the string terminus carry the highest voltage and are the ones that breach the ceiling first. Sensing at the module nodes — i.e., across each bus-section — is the natural, and arguably the only sensible, way to attribute the excess to a module and target the limiting. A POSITA designing a system that must throttle the right module is led directly to sectioned monitoring; it is a predictable arrangement of known sensing at known nodes.

Combination C result: claim 16 obvious.

7. Dependent claims

8. The § 103(c) trap — read this before drafting a contention

Because the applicant was Tigo Energy, Inc., much of the closest art is Tigo's own earlier work. Under pre-AIA § 103(c)(1) (in force for this 2009 application), subject matter that qualifies as prior art only under § 102(e), (f), or (g) cannot be used in a § 103 combination if, at the time the claimed invention was made, it and the claimed invention were commonly owned or subject to an obligation of assignment to the same person.

Consequences:

• US 7,602,080 B1 (Hadar et al., "Systems and methods to balance solar panels in a multi-panel system") — cited on the '074's face. If it qualifies only as § 102(e) art, it is disqualified from any § 103 combination against the '074. Do not build a combination on it without checking whether it also qualifies under § 102(a) or (b) as a publication. Its § 102(e) status also cannot be taken for granted — I did not verify its filing date in this session.
• US 2008/0097655 (= US 8,751,053) — not disqualified. It published 2008-04-24, more than a year before the July 30, 2009 provisional, so it is § 102(b) art, and § 103(c) reaches only art qualifying solely under 102(e)/(f)/(g). This is why the challenger's primary reference must be '655 and not the '080.
• The common ownership does not evaporate with the 2025–2026 assignment. § 103(c) is evaluated as of the time the claimed invention was made; the 2025-12-16 Patent Purchase Agreement transferring the portfolio to Tigo Energy Innovations LLC (see the assignment section of this file) does not retroactively remove the disqualification. The pre-AIA common-ownership shield attaches to the 2009 facts, not the current owner.

9. Objective indicia and counterarguments

Secondary considerations (Graham factor 4):

• Long-felt need — cuts against the patent, not for it. The problem (module voltage vs. a fixed string ceiling) was recognized in the art at least as early as Takehara '670 (2001). A recognized, decades-old need whose solution is a set-point change to an existing control loop is weak ground for nonobviousness.
• Commercial success — nexus problem. Tigo's MLPE products and its Smart-Curve / Reduced Voc feature ("the unit's output voltage does not vary when it is under load in cold temperatures… voltage is fixed no matter what the ambient temperature is" — Tigo Smart-Curve Application Note v1.3.4) are the commercial embodiments. ⚠️ That document post-dates the patent and is NOT prior art; it is cited here only as evidence of the commercial embodiment. Its existence cuts both ways: it confirms an industry need, but the causal link between the claimed architecture and the commercial success is weak, and the same market success is equally explained by the optimizer/rapid-shutdown market generally.
• Licensing program. The '074 appears on Tigo's virtual-marking page among the "Tigo-APsmart Licensed Patents" covering the APsmart RSD-S-PLC, RSD-S-PLC-B, RSD-D and RSD-D-15-1500 rapid-shutdown devices (https://www.tigoenergy.com/rsdvirtualmarking). A licensing program is not objective indicia of nonobviousness absent evidence that licensees took the license because of the claimed subject matter — and here the marking page groups the '074 with ~35 rapid-shutdown patents, suggesting it is part of a package rather than a standalone driver.
• Copying / industry adoption. Potentially available if competitors adopted temperature-independent output-voltage capping after Tigo; requires discovery.
• Praise / unexpected results. None that I can identify from the record.

Counterarguments a patent owner will raise, and my assessment:

10. Bottom line

The single most important finding: the applicant's own earlier publication, US 2008/0097655 A1, is § 102(b) art, is cited on the face of the '074, and discloses — verbatim — a single management unit, per-panel link modules each coupled between a panel and a common bus, per-panel voltage/current telemetry, per-panel power-on/power-off commands sent over the power bus, and "means to enable/disable panels." Claim 1's only arguable gap on that reference is the meaning of "limit," and the '074's own specification defines that word to include full on/off states. This is the reference the patent's own examiner put in the (56) block, and it is the reference that most obviously should have been applied.

11. What must be verified before any of this is filed

1. Pull the '074's complete (56) block, including the Foreign Patent Documents, "Other Publications," and Primary Examiner fields, and the full PDF of page 1 — my retrieval truncated it.
2. Pull the file wrapper for 12/562,933 — I cannot state whether any § 103 rejection issued, over what art, or what was argued.
3. Pull the full text of US 2008/0097655 / US 8,751,053 and confirm (a) the per-panel enable/disable passage at the paragraph level, (b) whether any disclosure addresses bus voltage limits rather than panel-level control, and (c) the priority chain back to provisional 60/852,961 (2006-10-18).
4. Pull Wolfs, Prexl, Ledenev, Besser, Bhavaraju '566, Kasai '739, Takehara '670, Kurokami '158 and chart them properly. My characterizations of Wolfs, Ledenev, Prexl, Adest, Moine, Kronberg, Takehara and Kurokami in this section rest on general knowledge of these references, not on text I read in this session, and are marked accordingly.
5. Verify claim 16–19 text from the granted patent, since the source I have truncates mid-claim-16.
6. Check whether the § 103(c) common-ownership shield was invoked or waived during prosecution — a matter the file wrapper will show.
7. Do not import the sibling patents' record. The SunSpec IPRs' results are claim- and patent-specific: IPR2021-01286 sustained the challenged '321 claims (Moine + Kronberg failed); IPR2021-01287 canceled '770 claims 12 and 13 over Adest '055. Neither holding tells you anything about the '074's claims, and the '074 has never been before the Board (see the PTAB section of this file). Moine + Kronberg in particular should be treated as a known-failed combination against this family, not a starting point.