Amicus Curiae Brief — CAO Lighting, Inc., Petitioner v. Wolfspeed, Inc., et al.

Supreme Court briefApr 9, 2026

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No. 25-1068

In the

Supreme Court of the United States

____________________

CAO LIGHTING, INC.,

Petitioner,

WOLFSPEED, INC., ET AL.,

Respondents.

ON PETITION FOR WRIT OF CERTIORARI TO THE UNITED

STATES COURT OF APPEALS FOR THE FEDERAL CIRCUIT

BRIEF OF AMICI CURIAE THE ASSOCIATION

FOR AMERICAN INNOVATION AND

PROFESSORS OF LAW IN SUPPORT OF

PETITIONER

FRANCISCO TSCHEN

Counsel of Record

TSCHEN LAW PLLC

2201 SW 145TH AVE #209

MIRAMAR, FL 33027

(571) 482-8540

ftschen@tschenlaw.com

Counsel for Amici Curiae

April 9, 2026

TABLE OF CONTENTS

Page

TABLE OF CONTENTS .............................................. i

TABLE OF AUTHORITIES....................................... iv

INTEREST OF AMICI CURIAE ................................ 1

SUMMARY OF ARGUMENT ..................................... 2

ARGUMENT ............................................................... 4

I. The PTAB Violated the Administrative

Procedure Act by Sustaining Invalidity by

Markedly Deviating from the Petition’s

Grounds Identified with Particularity .................. 4

I.A The PTAB Sustained Invalidity on a

Broader Theory than the Petition Set

Out for Element [21pre, a] ............................... 5

I.B The Hearing Confirms that the PTAB

and the Parties Understood the

170mW/1.5A as the Operative Petition

Ground. ............................................................. 6

I.C The PTAB also Violated the APA by

Converting a Factual Inquiry into a

Threshold Without Fair Notice ........................ 8

II. Rule 36 Affirmance Was Inadequate and

Not Conducive to Meaningful Review given

the Conflict with the District Court and

APA Violations Regarding the Bounds of

PTAB’s Power......................................................... 9

II.A The Rule 36 Judgment Leaves

Unexplained whether the Federal

Circuit Approved the PTAB’s Broadened

Grounds for Claim 21, its One-Percent

Threshold, or Some Other Rationale ............. 10

II.B 35 U.S.C. § 144 Confirms that the

Unexplained Affirmance was

Inadequate to Perform the Appellate

Function Congress Required Here ................. 12

III. Loper Bright Reinforces the Federal

Circuit’s Duty to Independently Review the

PTAB’s Dispositive Theories Rather than

Allow Them to Control in Silence........................ 13

III.A The PTAB was Purporting to Apply

the Same Claim Construction

Framework as the District Court,

Which Required Independent Judicial

Review ............................................................. 14

III.B Teva underscores the problem

because the Rule 36 Judgment Also

Leaves Unexplained What Standard of

Review the Federal Circuit Applied to

the Issue that Determined Invalidity ............ 15

III.C The U.S. Patent and Trademark

Office’s Own Subsequent Guidance

Confirms the Seriousness of the

Problem ........................................................... 16

iii

IV. The Federal Circuit’s Deference to the

PTAB Claim Construction Demonstrates

an Improper Extension of Deference Into

Article III Adjudication........................................ 17

IV.A Allowing the PTAB’s Broader Claim

21 Grounds to Control Revives Chevron

in Substance.................................................... 18

IV.B Allowing the PTAB’s One-Percent

Threshold to Control Repeats the Same

Error Through a Different Mechanism.......... 19

V. The PTAB’s IPR Scope Expansion Poses

Heightened Separation-of-Powers Risks ............ 21

VI. This Case Presents an Ideal Vehicle for

Clarifying Loper Bright’s Application to

Agency Adjudications........................................... 21

CONCLUSION .......................................................... 23

TABLE OF AUTHORITIES

Pages

CASES

Arthrex, Inc. v. Smith & Nephew, Inc.,

935 F.3d 1319 (Fed. Cir. 2019) ..............................5

CAO Lighting, Inc. v. GE Lighting, Inc.,

No. 1:20-cv-00681 (D. Del. May 10, 2022) ......... 3, 8

Chevron U.S.A. Inc. v.

Natural Resources Defense Council, Inc.,

467 U.S. 837 (1984) .................................. 18, 19, 21

DDR Holdings, LLC v. Priceline.com LLC,

122 F.4th 911 (Fed. Cir. 2024)............................. 10

Dell Inc. v. Acceleron, LLC,

818 F.3d 1293 (Fed. Cir. 2016) ........................ 4, 17

Elbit Sys. of Am., LLC v. Thales Visionix, Inc.,

881 F.3d 1354 (Fed. Cir. 2018) ............................ 12

In re Magnum Oil Tools Int’l, Ltd.,

829 F.3d 1364 (Fed. Cir. 2016) ..............................5

In re NuVasive, Inc.,

841 F.3d 966 (Fed. Cir. 2016) ................................5

Loper Bright Enterprises v. Raimondo,

603 U.S. 369 (2024) ............................ 2, 3, 4, 13, 15

17-18, 19, 20, 21

Lynk Labs, Inc. v. Samsung Co. Ltd.,

125 F.4th 1120 (2025) .......................................... 20

M & K Holdings, Inc. v. Samsung Elecs. Co.,

985 F.3d 1376 (Fed. Cir. 2021) .......................... 5, 7

Mandel v. Bradley,

432 U.S. 173 (1977) .............................................. 10

Markman v. Westview Instruments, Inc.,

517 U.S. 370 (1996) ........................................ 19, 22

Phil-Insul Corp. v. Airlite Plastics Co.,

854 F.3d 1344 (Fed. Cir. 2017) ...................... 10, 11

Phillips v. AWH Corp.,

415 F.3d 1303 (Fed. Cir. 2005) ............................ 14

Qualcomm Inc. v. Intel Corp.,

6 F.4th 1256 (Fed. Cir. 2021)................... 4, 8, 9, 17

Rates Tech., Inc. v. Mediatrix Telecom, Inc.,

688 F.3d 742 (Fed. Cir. 2012) .............................. 11

Redline Detection, LLC v. Star Envirotech Inc.,

811 F.3d 435 (Fed. Cir. 2015) .............................. 12

SAS Inst., Inc. v. Iancu,

584 U.S. 357 (2018) .................................. 4, 5, 7, 19

Skidmore v. Swift & Co.,

323 U.S. 134 (1944) .............................................. 21

Teva Pharm. USA, Inc. v. Sandoz, Inc.,

574 U.S. 318 (2015) ........................................ 10, 15

U.S. Surgical Corp. v. Ethicon, Inc.,

103 F.3d 1554 (Fed. Cir. 1997) ............................ 10

Utility Air Regulatory Group v. E.P.A.,

573 U.S. 302 (2014) .............................................. 20

West Virginia v. EPA,

597 U.S. 697 (2022) .............................................. 20

Wolfspeed, Inc. v. CAO Lighting, Inc.,

IPR2022-00847 (PTAB Sept. 28, 2023) ......... 3, 4, 5

STATUTES

5 U.S.C. § 554 ........................................................ 4, 17

5 U.S.C. § 556 ........................................................ 4, 17

5 U.S.C. § 706 ............................................................ 16

5 USC § 706(2)(D).................................................. 4, 17

35 U.S.C. § 144 ............................................ 2, 3, 12, 13

35 U.S.C. § 312(a)(3) ............................... 3, 4, 6, 13, 19

CONSTITUTIONAL PROVISIONS

U.S. Const., Article III ...... 2, 3, 4, 9, 12, 17, 19, 21, 22

RULES

Federal Circuit Rule 36 .................. 3, 9, 10, 11, 12, 13,

............................................................... 15, 16, 17

Supreme Court Rule 37.2............................................1

Supreme Court Rule 37.6............................................1

OTHER AUTHORITIES

Memorandum from Coke Morgan Stewart,

Acting Dir., U.S. Patent & Trademark

Office, PTAB Consideration of Prior

Findings of Fact and Conclusions of Law

(Sept. 16, 2025) .................................................... 17

The Federalist No. 78 (Alexander Hamilton)

(Clinton Rossiter ed., 1961) ................................. 22

INTEREST OF AMICI CURIAE 1

The Association for American Innovation

(https://aainnovation.org) (“AAI”) is a diverse

coalition of innovation ecosystem stakeholders. From

authors, inventors, scientists, manufacturers, and

engineers to attorneys, intellectual property

professionals, policy experts, entrepreneurs, and

investors. Our vision is a world in which America is

the unquestioned leader in technological innovation,

along with its allies and partners. We represent a

broad range of technology sectors and are committed

to supporting and promoting American technological

innovation. Our mission is rooted in a strong

belief: innovators must be given preference over

implementers. Innovation only happens when the

legal and economic systems guarantee innovators are

rewarded for their breakthroughs. Without the

breakthrough, there is nothing to build.

Professor Francisco Tschen is a Visiting

Lecturer at Florida International University College

of Law. His scholarship focuses on patent law and

related questions of administrative and international

law. Professor Tschen served at the U.S. Patent &

Trademark Office (“USPTO”) where he worked as a

Primary Patent Examiner and the Office of

International Patent Cooperation. He has a strong

Pursuant to Supreme Court Rule 37.6, counsel for the

amici curiae certifies that no party or counsel for any party

authored this brief in whole or in part and that no person or

entity other than the amici made a monetary contribution

intended to fund the preparation or submission of the brief. Rule

37.2 notice of the intent to file this brief was timely provided by

email to counsel of record for Petitioner and for Respondent.

scholarly interest in the legal rules applied by and to

the USPTO.

Professor Timothy T. Hsieh is an Associate Law

Professor at the Oklahoma City University School of

Law. His research and teaching focus on

administrative law, legislation and regulation,

antitrust and patent law. Professor Hsieh previously

practiced patent litigation, served as a judicial law

clerk for active federal patent judges, and worked as

an Patent Examiner at the U.S. Patent & Trademark

Office (“USPTO”). His professional experience and his

areas of scholarship give him a strong interest in the

sound development of the intersection between patent

and administrative law.

Both Professor Tschen and Professor Hsieh

submit this brief to underscore the importance of the

question presented to the constitutional separation of

powers and to the predictable administration of our

Nation’s patent system.

SUMMARY OF ARGUMENT

CAO Lighting’s petition argues that where there

is a conflict between the PTAB and an Article III court

on an issue of law, or where the PTAB decides a legal

question without notice or opportunity to be heard, it

is imperative that the Federal Circuit address both

the PTAB’s ruling on the legal issue and the conflict

in a written opinion consistent with Loper Bright, the

APA, and 35 U.S.C. § 144. We agree and support

Petitioner’s argument regarding the late breaking

claim construction that violated the APA and the

failure of the Federal Circuit to provide a required

analysis. We write separately to point out additional

PTAB deviance in this case that contradicts the APA

with further ramifications for Rule 36 and Section

144. This deviance by the PTAB and the failure by the

Federal Circuit to perform its oversight negatively

impact the innovation ecosystem that Amici fight to

protect.

This case presents a pressing question at the

intersection of patent law and administrative law,

and Article III separation of powers: whether the

Federal Circuit may allow the Patent Trial and

Appeals Board (“PTAB”) to sustain invalidity on new

dispositive grounds for satisfying adopted claim

constructions without fair notice, a meaningful

opportunity to respond, or meaningful judicial

explanation, consistent with this Court’s decision in

Loper Bright Enterprises v. Raimondo, 603 U.S. 369

(2024)—a decision restoring judicial duty and

rejecting agency deference. The District of Delaware

had already construed the relevant claim term, and

the PTAB purported to adopt that same construction.

See CAO Lighting, Inc. v. GE Lighting, Inc., No. 1:20cv-00681, Mem. Order at 18 (D. Del. May 10, 2022);

Final Written Decision at 53, Wolfspeed, Inc. v. CAO

Lighting, Inc., IPR2022-00847, Paper 69 (P.T.A.B.

Sept. 28, 2023) (“FWD”). But rather than decide the

claim on the grounds on which the claims were

challenged, the PTAB sustained invalidity on broader

grounds than the petition identified with

particularity. Cf. 35 U.S.C. § 312(a)(3). The PTAB

also made dispositive a threshold the district court

had already held was a factual question for the jury.

See id. at 21–22, 50–52; CAO Lighting, No. 1:20-cv00681, Mem. Order at 13–14. The Federal Circuit

then affirmed in one word through Rule 36, effectively

abdicating its Article III responsibility to provide

reasoned judicial review. This Court should grant

certiorari to ensure Loper Bright restores meaningful

judicial oversight rather than permitting agencies to

expand invalidity grounds while courts remain silent.

ARGUMENT

I. The PTAB Violated the Administrative

Procedure Act by Sustaining Invalidity by

Markedly Deviating from the Petition’s

Grounds Identified with Particularity

The Administrative Procedure Act (“APA”)

places adjudication on a simple premise: an agency

may not decide a case on a dispositive ground the

parties were never fairly given a chance to meet. See

5 U.S.C. §§ 554, 556, and 706(2)(D); Qualcomm Inc. v.

Intel Corp., 6 F.4th 1256, 1261–64 (Fed. Cir. 2021);

Dell Inc. v. Acceleron, LLC, 818 F.3d 1293, 1301–02

(Fed. Cir. 2016). As this Court explained in SAS, the

statute “envisions that a petitioner will seek an inter

partes review of a particular kind—one guided by a

petition describing ‘each claim challenged’ and ‘the

grounds on which the challenge to each claim is

based.’” SAS Inst., Inc. v. Iancu, 584 U.S. 357, 364,

138 S. Ct. 1348, 1355 (2018) (quoting 35 U.S.C.

§ 312(a)(3)). Yet the Patent Trial and Appeal Board

(“PTAB”) disregarded that rule in two related ways.

First, the PTAB sustained invalidity of a claim on

broader grounds than the ground on which the

petition had identified “with particularity.” 35 U.S.C.

§ 312(a)(3). See Petition for Inter Partes Review at

53–54, Wolfspeed, Inc. v. CAO Lighting, Inc.,

IPR2022-00847 (P.T.A.B. May 31, 2022) (“Pet”).

Second, the PTAB also made dispositive a factual

threshold on the meaning of “non-negligible,” even

though the District Court had already held that

whether that threshold was “non-negligible” was a

factual question for the jury and petitioner’s own

counsel told the PTAB at the hearing that the issue

was “not important to determine that here.”

Transcript of Oral Hearing at 41:9–41:23, Wolfspeed,

Inc. v. CAO Lighting, Inc., IPR2022-00847 (P.T.A.B.

July 18, 2023) (Paper 65) (“Tr.”)

I.A

The PTAB Sustained Invalidity on a

Broader Theory than the Petition Set

Out for Element [21pre, a]

The PTAB cannot advance a theory it finds more

persuasive that markedly deviates from what

petitioner relied upon. See M & K Holdings, Inc. v.

Samsung Elecs. Co., 985 F.3d 1376, 1385 (Fed. Cir.

2021). In SAS, this Court explained that inter partes

review is “guided by a petition” and that “it’s the

petitioner, not the Director, who gets to define the

contours of the proceeding.” SAS Inst., Inc. v. Iancu,

584 U.S. 357, 364–65, 138 S. Ct. 1348, 1355–56

(2018). That principle has been applied by the Federal

Circuit under the APA, and found to have violated the

APA where under the mantle of their agency power,

the PTAB “craft[s] its own theory of unpatentability,”

or relies on portions of the prior art different from

those presented in the petition and essential to its

obviousness finding. See Arthrex, Inc. v. Smith &

Nephew, Inc., 935 F.3d 1319, 1328 (Fed. Cir. 2019)

(discussing violations of APA by the PTAB in In re

Magnum Oil Tools Int'l, Ltd., 829 F.3d 1364 (Fed. Cir.

2016) and In re NuVasive, Inc., 841 F.3d 966, 967

(Fed. Cir. 2016)).

Despite precedent squarely on point, the PTAB

did exactly that here by purporting to adopt the same

claim construction as the District Court and relying

on portions of the prior art different than those

presented to invalidate under an obviousness

standard. Notably, under section 312(a)(3), the

petition challenged Element [21pre, a], particularly

as “Krames discloses this” because it teaches “[a]

power output of over 170 mW … at a drive current of

1.5 A dc.” Pet. 53–54. Patent Owner answered that

ground as presented. The PTAB then sustained

invalidity on a broader rationale, concluding that

Patent Owner had not persuasively disputed that the

Krames chip was capable of meeting the limitation at

amperages lower than the 1.5A on which the petition

relied upon. Judge Range raised the “procedural

concern” observing that “a person of skill would know

to go lower. Like how do I know from the petition that

that’s what you meant?” Tr. 15:24–16:4. Krames was

capable if it would “run it [at] lower” amperages (i.e.

lower than 1.5A). Id. at 21:1-21:5 This was a different

dispositive theory for satisfying claim 21 than the one

the petition itself identified with particularity for

Element [21pre, a].

I.B

The Hearing Confirms that the PTAB and

the Parties Understood the 170mW/1.5A

as the Operative Petition Ground.

The hearing confirms that the petition’s

challenge focused on the 170mW/1.5A ground that

Patent Owner was reasonably called upon to meet.

Judge Range identified a procedural concern and

asked how the Board could know from the petition

that petitioner meant a broader lower current ground

rather than the petition’s specific 170mW/1.5A

ground. Tr. 15:24–16:4. Judge Kaiser likewise

observed that, in Patent Owner’s position, he

probably would have instructed the expert to analyze

1.5A “because that’s what the petition talks about,”

and asked why the petition had focused on that

datapoint rather than the supposedly more “realistic”

lower-current operation. Id. at 18:25–19:19.

Petitioner responded that citing 170mW/1.5A had

simply been the “expedient” way to address the

limitation. Id. at 19:5–19:16.

That exchange confirms both that the Board

recognized the notice problem and that petitioner was

defending, at oral argument, a broader ground than

the petition had clearly set out for Element [21pre, a].

But the point of inter partes review is that the

petition—not later oral clarification—defines the

grounds of the case. See SAS Inst., Inc. v. Iancu, 584

U.S. 357, 364–65, 138 S. Ct. 1348, 1355–56 (2018);

M&K Holdings, Inc. v. Samsung Elecs. Co., 985 F.3d

1376, 1385–86 (Fed. Cir. 2021). The PTAB

nonetheless used that broader “capable of” rationale

to sustain invalidity. Patent Owner was entitled to

answer the grounds the petition actually identified

with particularity—not every possible way petitioner

might later say the limitation could be satisfied. The

PTAB nonetheless used that broader “capable of”

rationale to sustain invalidity. A reactive exchange at

hearing cannot cure the petition’s failure to identify

with particularity the broader ground the Board

ultimately adopted. Under the APA, Patent Owner

was entitled to fair notice in the petition itself, not

after-the-fact clarification at oral argument.

I.C

The PTAB also Violated the APA by

Converting a Factual Inquiry into a

Threshold Without Fair Notice

The PTAB committed the same kind of

procedural error on the patent’s claim 8 reflective

layers issue. In parallel litigation, the District Court

had rejected Defendants’ effort to impose a rigid

quantitative construction of the reflective layers,

holding only that the reflective layers must reflect

more than a negligible amount of light, and expressly

concluded that whether any accused product or prior

art reflects a non-negligible amount of light is “a

question of fact for the jury.” CAO Lighting, Inc. v. GE

Lighting, Inc., No. 1:20-cv-00681, Mem. Order at 13–

14 (D. Del. May 10, 2022). The PTAB purported to

adopt essentially that same construction, but then

displaced the district court’s law-fact line by making

dispositive a one-percent threshold (for what counts

as the non-negligible amount of light) that neither

party had litigated as the governing threshold.

The PTAB established its one-percent threshold

through a hearing exchange that did not provide the

notice the APA requires. As the Federal Circuit

explained in Qualcomm Inc. v. Intel Corp., 6 F.4th

1256, 1264 (Fed. Cir. 2021) a “single question-answer

exchange” and an “offhand comment” do not provide

adequate notice that the Board is about to make a

proposition dispositive. Yet that is effectively what

happened here. This one-percent threshold did not

appear in the parties’ claim-construction briefing as

the rule that would decide the case. Instead, the

transcript reflects one substantive question from

Judge Range to petitioner’s counsel, followed by a

brief citation follow-up, after which counsel

immediately told the Board that “it’s not important to

determine that here.” Tr. 41:9–41:23. The Board did

not announce a proposed one percent threshold,

request supplemental briefing, or ask Patent Owner

any question on whether “non-negligible” should be

reduced to a fixed numerical floor. The PTAB

nonetheless later held that “as little as one percent

light reflectance is ‘non-negligible’ in this context.”

FWD 21–22. That threshold was never fairly

presented through the adversarial process. Thus, the

PTAB failed to follow Qualcomm’s notice rule and in

doing so, violated the APA.

II. Rule 36 Affirmance Was Inadequate and

Not Conducive to Meaningful Review

given the Conflict with the District Court

and APA Violations Regarding the Bounds

of PTAB’s Power

Rule 36 affirmance was inadequate here because

it left unexplained how the Federal Circuit resolved

the dispositive issues presented on appeal. This was

not a routine appeal turning only on whether the

PTAB had enough evidence in the aggregate to

support invalidity. The appeal instead presented two

antecedent questions of law and process: whether the

PTAB could sustain invalidity on a broader theory

than the petition had identified for Element [21pre,

a], and whether the PTAB could convert a factual

inquiry about “non-negligible” reflectance into a

dispositive one-percent threshold. Yet the Federal

Circuit affirmed in one word.

In that posture, the affirmance under Rule 36

was not conducive to meaningful APA review. When

the PTAB makes dispositive a legal or quasi-legal

theory that differs from the way an Article III court

treated the same claim issue, an unexplained

affirmance leaves no way to know whether the

Federal Circuit independently agreed with the

agency’s reasoning, regarded any procedural defect as

harmless, or affirmed on some narrower ground. The

problem, then, is not simply brevity. It is the absence

of the explanation needed to determine whether the

PTAB acted within the petition-defined contours of

the proceeding and within the procedural limits the

APA imposes.

II.A

The Rule 36 Judgment Leaves

Unexplained whether the Federal Circuit

Approved the PTAB’s Broadened

Grounds for Claim 21, its One-Percent

Threshold, or Some Other Rationale

Claim construction is a question of law. Teva

Pharm. USA, Inc. v. Sandoz, Inc., 574 U.S. 318, 325

(2015). And the Federal Circuit has recognized that

neither it nor a district court is bound by the PTAB’s

claim constructions. DDR Holdings, LLC v.

Priceline.com LLC, 122 F.4th 911, 918 (Fed. Cir.

2024). While Rule 36 permits the court to “dispense

with issuance with issuing an opinion would have no

precedential value,” U.S. Surgical Corp. v. Ethicon,

Inc., 103 F.3d 1554, 1556 (Fed. Cir. 1997), that is not

the case here. Summary affirmances should “prevent

lower courts from coming to opposite conclusion on

the precise issues presented and necessarily decided

by those actions.” Mandel v. Bradley, 432 U.S. 173,

176, 97 S.Ct. 2238, 53 L.Ed.2d 199 (1977). See PhilInsul Corp. v. Airlite Plastics Co., 854 F.3d 1344, 1355

(Fed. Cir. 2017)

But the Rule 36 judgment leaves unexplained

whether the Federal Circuit independently agreed

with the PTAB’s broadened grounds under Element

[21pre, a], whether it independently approved the

PTAB’s one-percent threshold for “non-negligible”

reflectance, whether it thought either APA defect was

harmless, or whether it affirmed on some other

rationale altogether. That silence matters because

these were the steps that determined invalidity. A

Rule 36 judgment “simply confirms that the trial

court entered the correct judgment” and “does not

endorse or reject any specific part” of the tribunal’s

reasoning. Rates Tech., Inc. v. Mediatrix Telecom,

Inc., 688 F.3d 742, 750 (Fed. Cir. 2012); see also PhilInsul Corp. v. Airlite Plastics Co., 854 F.3d 1344,

1355–57 (Fed. Cir. 2017). If the Federal Circuit

believed PTAB had provided enough notice under the

APA, or that the PTAB was entitled to move from the

petition’s specific 170mW/1.5A ground to broader

grounds, or that the PTAB could convert a factual

inquiry about non-negligibility into a dispositive onepercent threshold, the Rule 36 affirmance does not

say so. Nor does it reveal whether the court instead

affirmed on some narrower basis.

In a case like this, where the appeal presented

antecedent questions about whether the PTAB

exceeded the petition-defined contours of the

proceeding and whether its procedures satisfied the

APA,

that

unexplained

affirmance

leaves

impermissible uncertainty about whether those

precise issues were actually and necessarily resolved.

II.B

35 U.S.C. § 144 Confirms that the

Unexplained Affirmance was Inadequate

to Perform the Appellate Function

Congress Required Here

Section 144 required an opinion here because

the appeal implicated both the lawful bounds of the

PTAB’s power and a conflict with the way an Article

III court had already treated the same patent issues.

The Patent Act requires a decision capable of

“govern[ing] the further proceedings in the case.” 35

U.S.C. § 144. A Rule 36 one-word affirmance cannot

perform that function when the PTAB has sustained

invalidity by moving beyond the petitioner’s

identified grounds and by adopting a dispositive

threshold on an issue the District Court had already

treated as factual.

To be sure, if two inconsistent conclusions may

reasonably be drawn from the evidentiary record, the

PTAB’s choice between them is ordinarily sustained

on substantial-evidence review. See Elbit Sys. of Am.,

LLC v. Thales Visionix, Inc., 881 F.3d 1354, 1356

(Fed. Cir. 2018); Redline Detection, LLC v. Star

Envirotech, Inc., 811 F.3d 435, 449 (Fed. Cir. 2015).

But that principle presupposes that the PTAB was

merely choosing between competing factual

inferences on properly noticed grounds. It does not

answer whether the PTAB was entitled to move

beyond the petition’s identified ground for Element

[21pre, a], or to convert the district court’s fact-bound

“non-negligible” inquiry into a dispositive one-percent

threshold. The District Court had already construed

the 40-milliwatt limitation and had already held that

the “non-negligible” inquiry was a question of fact for

the jury. If the Federal Circuit believed the PTAB

nonetheless had authority to proceed as it did, it

needed to say so and explain why.

The Rule 36 affirmance supplied none of the

guidance Section 144 required. The judgment gives no

indication whether the Federal Circuit thought the

district court’s earlier determinations still mattered,

whether the PTAB was free to move beyond the

petition’s identified grounds consistent with 35 U.S.C.

§ 312(a)(3) and the APA, or whether the court

believed the PTAB had not really done so at all. For

instance, it may be argued that the issues before the

PTAB and the District Court were not identical in

every respect. But that only underscores why

explanation was required. The PTAB purported to

adopt the District Court’s constructions while using

them to sustain invalidity on broader grounds for

claim 21 and through a dispositive threshold for claim

8. If those differences in posture or proof justified the

PTAB’s approach, the Federal Circuit needed to

explain why. Rule 36 did not, and Section 144

required more in a case like this.

III. Loper Bright Reinforces the Federal

Circuit’s Duty to Independently Review

the PTAB’s Dispositive Theories Rather

than Allow Them to Control in Silence

Loper Bright reinforces a basic principle directly

implicated here: courts must exercise independent

judgment on questions of law and may not allow

agency reasoning to control without meaningful

judicial explanation. 603 U.S. at 391–92, 412. That

principle matters here because the PTAB was not

merely weighing evidence within settled and properly

noticed grounds. Rather, the PTAB first sustained

invalidity of claim 21 on broader grounds than the

petition had identified with particularity for Element

[21pre, a], and then, on claim 8’s reflective-layers

issue, converted a factual inquiry the district court

had left to the jury into a dispositive one-percent

threshold. Those were not merely routine evidentiary

judgments. They were decisions about the legal and

procedural limits of the PTAB’s authority. The

Federal Circuit therefore could not permit those

grounds to control patentability without explaining

whether it independently agreed with them, believed

any APA defect was harmless, or affirmed on some

narrower basis.

III.A The PTAB was Purporting to Apply the

Same Claim Construction Framework as

the District Court, Which Required

Independent Judicial Review

Because the PTAB was purporting to apply the

same claim-construction framework as the District

Court, its displacement of the District Court’s

Interpretation required judicial review. The PTAB

was purporting to apply the same Phillips framework

that governs claim construction in District Court

Phillips v. AWH Corp., 415 F.3d 1303, 1312–13 (Fed.

Cir. 2005). On the Claim 21 170mW/1.5A ground, the

PTAB purported to adopt the same “capable of”

construction the District Court had already adopted,

but then used that construction to sustain invalidity

on a broader ground than the petition had identified

for Element [21pre, a], namely, that the Krames chip

could satisfy the limitation at currents lower than the

1.5A disclosure petitioner had relied on. FWD 15. On

claim 8, likewise, the PTAB purported to adopt the

District Court’s construction, but then overlaid a

dispositive one-percent threshold on an inquiry the

District Court had already treated as factual. FWD

21-22. In both instances, the PTAB claimed fidelity to

the governing construction while changing the

practical theory by which invalidity was established.

Under Loper Bright, the question is not whether

the PTAB and the District Court had to agree, but

whether the Federal Circuit could let the PTAB’s

outcome-determinative grounds prevail without

explanation. Loper Bright says courts must exercise

their own judgment on legal questions, including

here, whether the PTAB complied with the APA, and

whether the PTAB acted within the bounds of its

statutory authority to sustain invalidity. Yet here,

importantly, the Court remained silent without

disclosing whether the agency had remained within

the petition-defined and APA-defined limits of its

authority.

III.B Teva underscores the problem because

the Rule 36 Judgment Also Leaves

Unexplained What Standard of Review

the Federal Circuit Applied to the Issue

that Determined Invalidity

Although claim construction is ultimately a

question of law, it may rest on “subsidiary factfinding”

and

“evidentiary

underpinnings.”

Teva

Pharmaceuticals, 574 U.S. at 325-27 . That is

precisely why the Federal Circuit’s silence is so

problematic here. As to claim 21, the PTAB purported

to apply the legal construction already adopted by the

District Court, but then broadened the operative

grounds of satisfaction beyond the ground identified

in the petition. As to claim 8, the PTAB made

dispositive a one-percent threshold that effectively

resolved, as a threshold matter, an inquiry the

District Court had already treated as factual. Those

decisions raised questions not only about the

sufficiency of evidence, but also about the standard of

review and the lawful scope of the PTAB’s authority.

The Rule 36 judgment leaves all of that

unexplained. It does not reveal whether the Federal

Circuit viewed the PTAB as merely choosing among

permissible factual inferences, or instead as adopting

new dispositive theories that required independent

legal and procedural scrutiny. And it does not reveal

whether the court believed the PTAB had remained

within the petition’s identified grounds, or instead

thought any departure was harmless.

That silence is difficult to reconcile with the

APA’s command that courts decide legal questions for

themselves. See 5 U.S.C. § 706. If the Federal Circuit

thought the PTAB had merely made a factual

determination within an accepted construction, it

should have said so. If it thought the PTAB had made

a legal move by adding a dispositive quantitative

threshold, it should have explained why that move

was permissible despite the lack of notice and despite

the district court’s contrary treatment of the same

issue. It did neither.

III.C The U.S. Patent and Trademark Office’s

Own Subsequent Guidance Confirms the

Seriousness of the Problem

The Patent Office’s own later guidance confirms

the seriousness of the problem. On September 2025,

the Acting Director instructed that when the Board

reaches a finding of fact or conclusion of law different

from a prior district-court adjudication, “the Board

shall explain” why a different outcome is warranted,

and must provide a “more detailed explanation” when

the same or substantially the same evidence or

arguments are presented. Memorandum from Coke

Morgan Stewart, Acting Dir., U.S. Patent &

Trademark Office, to Members of the Patent Trial &

Appeal Bd., PTAB Consideration of Prior Findings of

Fact and Conclusions of Law (Sept. 16, 2025). That

directive does not cure the error here. An internal

agency memorandum cannot retroactively supply the

fair notice and meaningful opportunity to respond

that the APA requires, nor can it explain the Rule 36

judgment after the fact. See 5 U.S.C. §§ 554, 556, and

706(2)(D); Qualcomm Inc. v. Intel Corp., 6 F.4th 1256,

1261–64 (Fed. Cir. 2021); Dell Inc. v. Acceleron, LLC,

818 F.3d 1293, 1301–02 (Fed. Cir. 2016).

The memorandum does underscore petitioner’s

central point: unexplained agency displacement of

previously litigated grounds is untenable. Patent

Owners and the Public alike are entitled to know

what patent rights mean before those rights are taken

away. When the PTAB broadens grounds and

imposes dispositive quantitative threshold to sustain

invalidity, and the Federal Circuit permits that result

to stand without explanation, fair process and judicial

review both suffer. Loper Bright reaffirmed that

courts must exercise their own judgment on questions of

law . This Court should grant certiorari to ensure that

patent rights are not lost through unexplained agency

decisions.

IV. The Federal Circuit’s Deference to the

PTAB Claim Construction Demonstrates

an Improper Extension of Deference Into

Article III Adjudication

In Loper Bright v. Raimondo, this Court made

clear that the Framers envisioned that the final

“interpretation of the laws” would be “the proper and

peculiar province of the courts.” 603 U.S. at 385

(citations omitted). To ensure the “steady, upright

and impartial administration of the laws,” the Court

further held that the Constitution should allow judges

to exercise that judgment rather than allow Executive

branch agencies to supply controlling legal meaning

by default. Id. The Federal Circuit allowed the PTAB

to sustain invalidity on broader grounds than the

petition identified for claim 21 and to impose a

dispositive one-percent threshold on claim 8, even

though the District Court had already treated that

issue as factual. That is precisely the form of agencybiased deference Loper Bright explicitly prohibits.

Specifically, the Federal Circuit’s approach in

deferring to the PTAB’s determination reflects a

deeper issue: whether an agency’s adjudicatory

choices may effectively become controlling law when

the court of appeals provides no explanation of its

own. That move constitutes undue judicial deference

to agency practice and contradicts both the Patent

Act, the APA, and this Court’s command in Loper

Bright that courts must independently determine the

law.

IV.A Allowing the PTAB’s Broader Claim 21

Grounds to Control Revives Chevron in

Substance

Even if the PTAB is right that Krames could

have been operated at lower current while still

satisfying claim 21, that does not answer the real

question: who decides whether that broader rationale

falls within the grounds the petition identified with

particularity? If the PTAB may answer that question

for itself, and the Federal Circuit may affirm in

silence, then the agency, not the courts, determine the

bounds of IPR. See Chevron U.S.A. Inc. v. Natural

Resources Defense Council, Inc., 467 U.S. 837 (1984).

That is the structural error Loper Bright rejected.

Questions about the scope of agency power,

compliance with § 312(a)(3), and the adequacy of

notice under the APA are legal questions for courts to

decide independently. Courts may not allow

executive-branch practices—whether formal policies

or entrenched examination customs—to define

statutory meaning. Loper Bright, 603 U.S. at 385.

If a court permits that kind of shift without

explanation, it effectively allows the agency to define

the scope of the petition for itself—contrary to what

this Court established in SAS. That is deference in

substance, even if it is not labeled as such. Allowing

administrative agency standards to migrate into

Article III adjudication permits the PTAB to shape

substantive patent law through practice rather than

legislation.

IV.B Allowing the PTAB’s One-Percent

Threshold to Control Repeats the Same

Error Through a Different Mechanism

The same problem appears on claim 8’s

reflective layers issue. The District Court held that

whether a layer reflected a “non-negligible” amount of

light was a factual question for the jury. The PTAB

purported to adopt that same construction, yet then

made dispositive its own one-percent threshold. That

was not merely routine reasonable factfinding, it

displaced the District Court’s law-fact line.

Instead of applying the standard under

Markman, the PTAB asked whether the agency’s

preferred view made sense. The two questions are not

the same, and Loper Bright emphatically forbids

conflating them. Judicial independence is not

maintained by relabeling deference as “logic.” As this

Court warned in West Virginia v. EPA, 597 U.S. 697,

723 (2022), courts must hesitate before concluding

that Congress means to confer upon agencies

“unheralded power” representing a “transformative

expansion in [their] regulatory authority.” 597 U.S. at

724 (citing Utility Air Regulatory Group v. E.P.A., 573

U.S. 302, 324 (2014)). The Federal Circuit’s

acceptance of the PTAB’s administrative practice—as

done here with respect to deferring to PTAB imposed

rules of decision—is exactly the kind of unheralded

expansion Loper Bright sought to prevent.

The Federal Circuit effectively deferred here to

the PTAB’s adjudicatory practices by allowing the

PTAB to reshape IPR practice and scope. In doing so,

it allowed the PTAB to expand the practical bounds of

IPR. In Lynk Labs, Inc. v. Samsung Co. Ltd., 125

F.4th 1120 (2025), the Federal Circuit framed its

analysis as statutory interpretation while allowing

executive-branch reasoning to dictate the result.

Similarly in this case, the Federal Circuit avoided its

independent interpretive responsibility by permitting

the PTAB’s agency imposed procedural rules to do the

work.

This is problematic because the PTAB combines

adjudicatory authority with institutional incentives

favoring patent invalidation and administrative

efficiency. Without meaningful judicial review, those

incentives can harden into de facto law. Loper Bright

requires more. It requires courts to independently

interpret statutes—even where doing so disrupts

administrative practice or long-standing precedent.

The Federal Circuit failed to meet that obligation

here. This Court should grant review to reaffirm that

legal interpretation, and claim construction is

governed by Article III judicial analysis—not by the

PTAB administrative practices.

V. The PTAB’s IPR Scope Expansion Poses

Heightened Separation-of-Powers Risks

The separation-of-powers concern here is acute.

The PTAB is an executive tribunal whose

administrative judges lack Article III protections. Yet

the Board adjudicates questions that go to the core of

claim construction and the scope of rights afforded

under carefully drafted patent claims. When courts

defer to the PTAB adjudications that differ from

Article III interpretation, they effectively permit the

Executive Branch to define the scope of its own

authority. As this Court has cautioned, courts, not

agencies, will decide “all relevant questions of law”

arising on review of agency action. Loper Bright, 603

U.S. at 371. That principle applies with full force to

agency adjudications.

VI. This Case Presents an Ideal Vehicle for

Clarifying Loper Bright’s Application to

Agency Adjudications

This Court has not yet issued a decision applying

Loper Bright to agency adjudications. Lower courts

have cited Loper Bright sparingly, often without

explaining how independent judicial judgment should

function in practice. Namely, the Court should

provide guidance with respect to where this new

Loper Bright deference lies on the scale of being less

deferential than Chevron and more deferential than

Skidmore. See Skidmore v. Swift & Co., 323 U.S. 134

(1944).

This case presents a clean and consequential

opportunity to do so. The Federal Circuit’s disposition

allowed the PTAB adjudications to control the

resolution of IPR scope and claim-constructionrelated questions without any reasoned explanation

of the court’s own. But claim construction, and the

legal boundaries that govern how claim language may

be used to sustain invalidity, remain matters for

Article III courts. See Markman v. Westview

Instruments, Inc., 517 U.S. 370, 383 (1996). The

implications for patent law, innovation, and

constitutional structure are therefore substantial.

As the Federalist Papers remind us, the

judiciary was designed to be “an intermediate body

between the people and the legislature” and “to keep

the latter within the limits assigned to their

authority.” The Federalist No. 78 (Alexander

Hamilton) (Clinton Rossiter ed., 1961). That same

duty applies, with equal or greater force, to executive

agencies. Courts serve as the buffer that prevents

administrative

convenience

from

becoming

administrative law. When courts adopt an agency’s

actions or interpretations wholesale, they cease to

perform that constitutional function. They become,

instead, the agency’s institutional echo.

CONCLUSION

By permitting the PTAB to sustain invalidity on

broader grounds than the petition identified for claim

21, and to impose a dispositive one-percent threshold

on claim 8, without meaningful judicial explanation,

the Federal Circuit allowed agency reasoning to

control where independent judicial judgment was

required. The petition for a writ of certiorari should

be granted. The judgment below should be vacated.

Respectfully submitted,