NOTE: This disposition is nonprecedential.

 

United States Court of Appeals 

for the Federal Circuit ______________________ 

POLARIS INNOVATIONS LIMITED,

Appellant

v.

ADVANCED MICRO DEVICES, INC.,

Cross-Appellant

______________________ 

2021-1917, 2021-1958

______________________ 

Appeals from the United States Patent and Trademark 

Office, Patent Trial and Appeal Board in No. IPR2019-

01527.

______________________ 

Decided: July 18, 2022

______________________ 

ROBERT E. FREITAS, Freitas & Weinberg LLP, Redwood 

Shores, CA, argued for appellant.

 AASHISH G. KAPADIA, Baker Botts L.L.P., Austin, TX, 

argued for cross-appellant. Also represented by BRIAN W.

OAKS; MICHAEL HAWES, Houston, TX.

______________________ 

Before MOORE, Chief Judge, PROST and HUGHES, Circuit 

Judges.

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PROST, Circuit Judge. 

Advanced Micro Devices, Inc. (“AMD”) petitioned for 

inter partes review (“IPR”) of claims 1–3, 5, 9–15, 17, and 

21–25 of U.S. Patent No. 8,117,526 (“the ’526 patent”), 

which Polaris Innovations Ltd. (“Polaris”) owns. In a final 

written decision, the Patent Trial and Appeal Board 

(“Board”) concluded that AMD had proved unpatentable 

only claims 1, 9, 12, 24, and 25. Advanced Micro Devices, 

Inc. v. Polaris Innovations Ltd., No. IPR2019-01527, Paper 

28 (P.T.A.B. Feb. 26, 2021) (“Final Written Decision”). 

Each party appeals aspects of the decision adverse to it. 

We affirm in part and dismiss in part. 

DISCUSSION

We first address the merits of Polaris’s appeal. We 

then consider whether aspects of AMD’s cross-appeal are 

improperly before us and whether AMD has standing before turning to the merits of the cross-appeal.

I 

Polaris limits its challenges on appeal to claim 9, raising three arguments. It first contends that the Board erred 

in construing “checksum” to include simple parity bits calculated across disjoint inputs. Second, it argues that substantial evidence does not support the Board’s obviousness 

determination, even under the Board’s construction of 

“checksum.” And third, it suggests that the Board violated 

the Administrative Procedure Act (“APA”) by relying on a 

prior-art reference for its construction of “checksum” that 

neither party raised and to which Polaris never had an opportunity to respond. We consider each argument in turn 

and conclude that none has merit. 

We start with Polaris’s challenge to the Board’s construction of “checksum.” AMD asked the Board to construe 

“checksum” to mean “a plurality of ECC [error correction 

code] bits.” Final Written Decision, at 13. Polaris disagreed, arguing that “checksum” “encompasses a multi-bit 

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error detection or correction data structure whose bits are 

calculated using non-disjoint sets of inputs.” Id. But Polaris also sought to exclude from the construction “a set of 

simple parity bits, calculated from non-overlapping sets of 

inputs.” Id. at 16. The Board rejected both parties’ attempts to limit the scope of the term, concluding that 

“checksum” encompasses ECC bits but is not limited to 

them and that it includes a set of simple parity bits calculated from non-overlapping sets of inputs. Id. at 18. On 

appeal, Polaris contends that this construction ignores the 

’526 patent’s teachings that checksums and simple parity 

bits are distinct concepts with distinct applications.1 The 

problem with this argument is twofold. First, the fact that 

checksums and simple parity bits are distinct concepts does 

not, as Polaris seems to suggest, preclude the Board’s construction, in which checksums encompass simple parity 

bits but are not coextensive with them. See Appellant’s 

Br. 21–23. Second, nothing in the ’526 patent’s specification supports the narrowing limitation Polaris urges. As 

Polaris’s counsel conceded at oral argument, the specification and claims both state that checksums encompass 

1 Polaris also suggests that it was inappropriate for 

the Board to resort to extrinsic evidence to construe “checksum” after concluding that the inventor had acted as his 

own lexicographer in the ’526 patent. Appellant’s Br. 

24–25. But the case Polaris cites, Multiform Desiccants, 

Inc. v. Medzam, Ltd., simply says that if the specification 

makes the meaning of a claim term sufficiently clear, that 

meaning shall apply. See 133 F.3d 1473, 1477 (Fed. Cir. 

1998). So it does not support a categorical rule that one 

cannot consult extrinsic evidence when the inventor acts as 

his own lexicographer. And, in any event, the Board did 

not resort to extrinsic evidence to construe checksum; rather, it explained why the extrinsic evidence Polaris relied 

on was inconsistent with the specification. See Final Written Decision, at 16–18.

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error-correcting bits, and such bits can be calculated from 

overlapping and non-overlapping sets of inputs. Oral Arg. 

at 5:38–8:35, No. 21-1917, https://oralarguments.cafc.uscourts.gov/default.aspx?fl=21-1917_0705202

2.mp3. We therefore conclude that the Board’s construction was correct.

We turn next to Polaris’s contention that the Board’s 

obviousness analysis never addressed whether the prior 

art discloses a “checksum [determined] based on the data 

bits and the first and second indicators.” Polaris says that 

the Board mistakenly observed that Polaris never addressed any element of claim 9 other than “checksum.” We 

disagree. The full context of Board’s analysis shows that it 

considered all of Polaris’s arguments and that, in saying 

that Polaris had not addressed any other claim element besides “checksum,” it was talking about the “checksum [determined] based on the data bits and the first and second 

indicators.” The Board first refers to Polaris’s arguments 

relating to “the required ‘checksum,’” and a review of the 

underlying citations shows that the arguments the Board 

was referencing include Polaris’s arguments relating to the 

“checksum [determined] based on the data bits and the 

first and second indicators.” See Final Written Decision, at

55 (citing J.A. 892–95 (Patent Owner Resp. 51–54) and 

977–79 (Przybylski Decl. ¶¶ 165, 168–70)). The Board then

observed that it had “review[ed] the record” and “confirm[ed AMD]’s analysis of the remaining requirements of 

claim 9,” reaffirming that it had considered the entire record and concluded that AMD had met its burden of proof. 

See Final Written Decision, at 57. These two statements 

indicate that the Board considered and rejected Polaris’s 

arguments on this limitation, and Polaris has not otherwise articulated why the Board’s conclusion is unsupported 

by substantial evidence.

We conclude our discussion of Polaris’s appeal with its 

argument that the Board violated the APA by relying on a 

prior-art reference that neither party had cited to construe 

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“checksum.” Specifically, Polaris says that the Board relied on a reference, Maxino, that AMD had cited only in its 

invalidity discussion, not in the claim-construction context. 

As a result, Polaris contends, it had no opportunity to respond to the Board’s novel theory. But the Board did not 

rely on Maxino to construe “checksum.” Rather, the Board 

merely observed, using a “see also” citation, that Maxino 

was consistent with the idea that a checksum encompasses 

simple parity bits calculated from non-overlapping sets of 

inputs, a conclusion that the Board reached independently 

of Maxino’s disclosure. See Final Written Decision, at

16–17. We see no APA violation in the Board’s use of Maxino in this manner.

Seeing no merit in Polaris’s arguments, we affirm the 

Board’s determination that claim 9 of the ’526 patent is unpatentable as obvious.

II

A 

Before turning to the merits of AMD’s cross-appeal, we 

must address two threshold issues. First, AMD cross-appeals the Board’s determinations with respect to claims 1, 

9, 12, 24, and 25 despite prevailing on those claims before 

the Board; accordingly, its cross-appeal is improper as to 

those claims, and we dismiss them. Second, Polaris argues 

that AMD does not have standing to appeal the Board’s decision with respect to claims 2, 3, 5, 10, 11, 13–15, 17, and 

21–23 because Polaris did not assert them in its districtcourt case against AMD. We disagree.

“Standing to sue is a doctrine rooted in the traditional 

understanding of a case or controversy.” Spokeo, Inc. v. 

Robins, 578 U.S. 330, 338 (2016). “To establish standing, 

the party invoking federal jurisdiction must demonstrate 

(1) an injury in fact that is (2) fairly traceable to the defendant’s challenged conduct and is (3) likely to be redressed by a favorable judicial decision.” Apple Inc. v. 

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Qualcomm Inc., 17 F.4th 1131, 1135 (Fed. Cir. 2021) (addressing appellate standing in IPR appeals) (cleaned up). 

“To establish injury in fact, [an appellant] must show that 

he or she suffered an invasion of a legally protected interest 

that is concrete and particularized and actual or imminent, 

not conjectural or hypothetical.” Spokeo, 578 U.S. at 339 

(cleaned up).

AMD has sufficiently demonstrated imminent harm. 

Polaris filed an open-ended infringement complaint in district court alleging that AMD had infringed “one or more 

claims of the ’526 patent.” Polaris Innovations Ltd. v. Advanced Micro Devices, Inc., Case No. 1:18-cv-555, ECF No. 

1 (W.D. Tex. July 2, 2018). And Polaris has not said that it 

would not assert other claims against AMD if we upheld

the unpatentability of claim 9, as we have done. An appellant shows standing when it demonstrates that it is engaging in “activity that would give rise to a possible 

infringement suit.” Consumer Watchdog v. Wis. Alumni 

Rsch. Found., 753 F.3d 1258, 1262 (Fed. Cir. 2014). Here, 

AMD “has engaged in acts that not only could give rise to 

a possible infringement suit, but did give rise to an infringement suit.” Grit Energy Sols., LLC v. Oren Techs., 

LLC, 957 F.3d 1309, 1320 (Fed. Cir. 2020) (emphasis in 

original). And AMD’s injury is compounded by the fact that 

IPR estoppel has attached to each of the claims it challenged in the IPR. See Altaire Pharms., Inc. v. Paragon 

Bioteck, Inc., 889 F.3d 1274, 1283 (Fed. Cir. 2018) (noting 

that “the estoppel effect in this case further supports Altaire’s claimed injury in fact”), remand order modified by 

stipulation, 738 F. App’x 1017. That injury is traceable to 

Polaris’s conduct, and a favorable judicial decision would 

remove at least a subset of the ’526 patent’s claims as an 

obstacle to AMD’s allegedly infringing activity. We conclude, therefore, that AMD has standing to bring its crossappeal. Accordingly, we turn to its merits.

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B 

AMD raises two challenges, but it can prevail on the 

second only if it prevails on the first: that the Board erred 

in failing to consider AMD’s motivation-to-combine argument. Because we conclude that the first challenge is meritless, we do not reach the second. 

AMD argues that its petition identified multiple combinations of Sridhara2 and Iglesia3 and motivations for 

each—one combination starting with Iglesia (the Iglesiafirst theory) and another starting with Sridhara (the Sridhara-first theory)—but the Board only addressed one of 

them. In AMD’s view, the Board should have addressed 

each combination explicitly and separately.

The Board did not err. Its motivation-to-combine analysis focused on the Iglesia-first theory, but the decision was 

not limited to it. The Board began its analysis by agreeing 

with Polaris that AMD “has not proved by a preponderance 

of the evidence that a person of ordinary skill in the art 

would have been motivated to combine the teachings of Iglesia and Sridhara,” without regard to which acted as the 

primary reference. J.A. 34. It then explicitly referenced 

AMD’s Sridhara-first argument in addressing AMD’s belatedly raised theory based on Sridhara alone, observing 

that “the portions of the Petition relied on present [AMD]’s

obviousness arguments solely based on the combination of 

Sridhara with Iglesia.” J.A. 39 (emphasis in original); see 

also id. (“[AMD] relies on the system architecture of Iglesia 

to account for the lack of explicit disclosure in Sridhara of 

a system with a processor and circuits.”). Together, these 

2 Sridhara et al., Coding for System-on-Chip Networks: A Unified Framework, Vol. 13, No. 6 IEEE Transactions on Very Large Scale Integration (VLSI) Systems, 655 

(2005).

3 U.S. Patent No. 6,490,703.

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statements show that the Board was aware of AMD’s Sridhara-first theory and had concluded that it, like the Iglesia-first theory, lacked merit. Further, the Board’s focus 

on the Iglesia-first theory matched AMD’s petition, which 

likewise substantially focused on that theory. We conclude 

that the Board addressed every ground of invalidity AMD 

raised. We therefore affirm the Board’s determination that 

AMD failed to show by a preponderance of the evidence 

that a skilled artisan would have been motivated to combine Iglesia and Sridhara.

CONCLUSION

We have considered the parties’ remaining arguments 

but find them unpersuasive. For the reasons set forth 

above, we affirm in part and dismiss in part. 

AFFIRMED-IN-PART AND DISMISSED-IN-PART

COSTS

No costs.

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