Court Opinion

ID: 5141073
Source: CourtListenerOpinion
Date Created: 2021-12-28 17:01:20.126086+00
Date Added: 2024-06-11T08:24:27.190623
License: Public Domain

Case: 20-1664   Document: 103    Page: 1     Filed: 12/28/2021

    United States Court of Appeals
        for the Federal Circuit
                  ______________________

                INTEL CORPORATION,
                      Appellant

                            v.

            QUALCOMM INCORPORATED,
                      Appellee
               ______________________

                        2020-1664
                  ______________________

     Appeal from the United States Patent and Trademark
 Office, Patent Trial and Appeal Board in No. IPR2018-
 01429.
                  ______________________

                Decided: December 28, 2021
                  ______________________

     GREGORY H. LANTIER, Wilmer Cutler Pickering Hale
 and Dorr LLP, Washington, DC, argued for appellant. Also
 represented by DAVID LANGDON CAVANAUGH, THOMAS
 SAUNDERS; BENJAMIN S. FERNANDEZ, Denver, CO; JASON
 KIPNIS, Palo Alto, CA; CRISTINA SALCEDO, Los Angeles, CA.

    JONATHAN S. FRANKLIN, Norton Rose Fulbright US
 LLP, Washington, DC, argued for appellee. Also repre-
 sented by PETER B. SIEGAL; STEPHANIE DEBROW, EAGLE
 HOWARD ROBINSON, Austin, TX; DANIEL LEVENTHAL,
 RICHARD STEPHEN ZEMBEK, Houston, TX.
                ______________________
Case: 20-1664     Document: 103      Page: 2   Filed: 12/28/2021

 2              INTEL CORPORATION   v. QUALCOMM INCORPORATED

     Before PROST, TARANTO, and HUGHES, Circuit Judges.
 PROST, Circuit Judge.
     Intel Corporation (“Intel”) petitioned the Patent Trial
 and Appeal Board (“Board”) for inter partes review (“IPR”)
 of various claims of U.S. Patent No. 8,229,043 (“the
 ’043 patent”), owned by Qualcomm Incorporated (“Qual-
 comm”). Intel proved unpatentable some (but not all) of
 these claims and some (but not all) of Qualcomm’s proposed
 substitute claims. Now, Intel appeals the Board’s determi-
 nations regarding the surviving claims. We affirm as to the
 originally challenged claims, but we vacate as to the sub-
 stitute claims. We remand for further proceedings.
                         BACKGROUND
                              I
      This appeal relates to radio frequency communication
 systems. On the sending end of such systems, a sending
 device converts a data signal (e.g., voice data) to a higher
 “carrier” frequency for transmission over the air. On the
 receiving end, a receiving device down-converts (or demod-
 ulates) that signal to its original “baseband” frequency.
 The receiver can also amplify the signal via an amplifier.
 A “low-noise amplifier” (“LNA”), for example, does so while
 minimizing noise, which distorts the signal. “Gain” quan-
 tifies the amplification a system provides, and the need for
 it varies with the incoming signal’s strength.
      Qualcomm’s patent is about the receiving end. Enti-
 tled Stepped Gain Mixer, it discloses a “mixer” (i.e., the
 component that performs demodulation) in a “receiver
 front end” that provides “stepped gain control” (i.e., gain
 adjustment in a stepwise manner). ’043 patent col. 1
 ll. 6–8. It explains that receivers with “many fine gain
 steps,” as opposed to “just a few large gain steps,” can
 “achieve a consistently high and smooth signal-to-noise ra-
 tio over a large gain range”—which helps them keep pace
 with the “higher data rates” of newer systems on the
Case: 20-1664    Document: 103     Page: 3   Filed: 12/28/2021

 INTEL CORPORATION   v. QUALCOMM INCORPORATED              3

 sending end. Id. at col. 1 ll. 21–27, 54–57. Pursuing that
 benefit, therefore, the patent uses “multiple gain states.”
 Id. at col. 2 ll. 9–12.
     Take the example pictured below (Qualcomm’s annota-
 tion of ’043 patent Fig. 2). Antenna 16 receives radio fre-
 quency input signal 32, which is amplified by one of three
 LNAs 17–19 and then (annotated in red) proceeds to tran-
 sistors 39 and 40 of stepped gain mixer 38. The mixer de-
 modulates this carrier signal by processing it with local
 oscillator signal 36. The signal ultimately emerges as base-
 band signal 84. Notably, switches 41 and 42 can alter the
 gain. Closing switch 41 (forming a connection) and opening
 switch 42 (breaking a connection) increases gain, as the
 transistor outputs (green and blue) add to make a higher-
 amplitude baseband signal (yellow):

 J.A. 3697. Things change if the switches’ states are
 swapped. Then, green goes to ground while blue becomes
 the baseband:
Case: 20-1664     Document: 103      Page: 4   Filed: 12/28/2021

 4              INTEL CORPORATION   v. QUALCOMM INCORPORATED

 J.A. 3698. Thus, toggling “two mixer gain modes for each
 of three amplifier gain modes” translates to “six gain
 states.” Id. at col. 7 ll. 24–26.
                               II
      Intel petitioned for IPR identifying itself and its cus-
 tomer Apple, Inc. (“Apple”) as real parties-in-interest. Intel
 Corp. v. Qualcomm Inc., No. IPR2018-01429, 2020 WL
 573274, at *1 (P.T.A.B. Jan. 30, 2020) (“Final Written De-
 cision”). It advanced three unpatentability grounds: that
 claims 1, 17, 19, and 21 were anticipated by Der 1; that
 claims 2, 3, and 7 were obvious in view of Der and Razavi 2;
 and that claims 1–3, 6, 7, 17–19, and 21 were obvious in
 view of Der and Valla. 3 Id. at *3. Intel prevailed on
 claims 1–3 and 7 but not claims 6, 17–19, and 21. Id.
 at *30. Granting in part Qualcomm’s motion to amend, the
 Board replaced claims 2, 3, and 7 with substitute claims 27,

     1   Lawrence Der & Behzad Razavi, A 2-GHz CMOS
 Image-Reject Receiver with LMS Calibration, 38(2) IEEE J.
 Solid-State Circuits 167 (2003).
     2   Behzad Razavi, Rf Microelectronics (1998).
     3   Valla et al., A 72-mW CMOS 802.11a Direct Con-
 version Front-End With 3.5-dB NF and 200-KhZ 1/f Noise
 Corner, 40(4) IEEE J. Solid-State Circuits 970 (2005).
Case: 20-1664     Document: 103       Page: 5    Filed: 12/28/2021

 INTEL CORPORATION    v. QUALCOMM INCORPORATED                  5

 28, and 31 after disagreeing that these claims were obvious
 in view of Der, Razavi, and Burgener. 4 Id. at *28, *30.
     After Intel appealed, Qualcomm moved to dismiss for
 lack of standing. We denied that motion and directed the
 parties to address standing in their briefs. 5 We have juris-
 diction over final Board decisions under 28 U.S.C.
 § 1295(a)(4)(A). As discussed below, Intel has standing to
 invoke that jurisdiction.
                          DISCUSSION
                                I
     Before proceeding to the merits, we address the thresh-
 old question of our jurisdiction. We are limited to deciding
 “cases” and “controversies.” U.S. CONST. art. III, § 2. This
 “fundamental limitation” is reflected in the Article III
 standing requirement. Summers v. Earth Island Inst.,
 555 U.S. 488, 493 (2009). Although “not necessarily a re-
 quirement to appear before an administrative agency,” it
 “kicks in when a party seeks review in a federal court.” Ap-
 ple Inc. v. Qualcomm Inc., 17 F.4th 1131, 1135–36
 (Fed. Cir. 2021) (cleaned up). That party must demon-
 strate: (1) an “injury in fact” (2) “fairly traceable” to the de-
 fendant’s challenged conduct and (3) “likely to be redressed
 by a favorable judicial decision.” Spokeo, Inc. v. Robins,
 578 U.S. 330, 338 (2016).
     Relevant here, an injury in fact must be “concrete and
 particularized and actual or imminent, not conjectural or
 hypothetical.” Id. at 339 (cleaned up). That’s generally so
 when an IPR petitioner “has engaged in, is engaging in, or
 will likely engage in activity that would give rise to a pos-
 sible infringement suit.” Grit Energy Sols., LLC v. Oren

     4   U.S. Patent No. 6,804,502.
     5   We also denied Apple’s motions to intervene and to
 participate as amicus curiae.
Case: 20-1664     Document: 103      Page: 6   Filed: 12/28/2021

 6              INTEL CORPORATION   v. QUALCOMM INCORPORATED

 Techs., LLC, 957 F.3d 1309, 1319 (Fed. Cir. 2020) (cleaned
 up). The appellant in Grit, for instance, engaged in acts
 that not only could have but “did give rise to an infringe-
 ment suit”—a suit dismissed without prejudice, leaving the
 patentee “free to reassert those infringement claims.” Id.
 at 1320. Intel’s predicament here is similar. Although
 Qualcomm didn’t sue Intel for infringement, Qualcomm
 has not disputed that it mapped the ’043 patent claims to
 an Intel product (and only an Intel product) in a prior suit
 against Apple. See Appellant’s Br. 46; J.A. 4713–65;
 J.A. 4794–96; Intel’s Response to Qualcomm’s Motion to
 Dismiss, ECF No. 40 at 5 (and cited exhibits)). Like in Grit,
 therefore, Intel’s acts “did give rise to an infringement
 suit.” 957 F.3d at 1320. In Intel’s words, Qualcomm “al-
 ready has engaged in litigation involving that technology
 and this patent.” Reply Br. 29.
     It is of no moment that the suit wasn’t against Intel, as
 Intel “need not face a specific threat of infringement.” Grit,
 957 F.3d at 1319 (cleaned up). Nor does it matter that the
 suit settled in 2019. See J.A. 4594–95. True, such settle-
 ments can deprive parties of standing. E.g., Apple,
 17 F.4th at 1134; Apple Inc. v. Qualcomm Inc., 992 F.3d
 1378, 1385 (Fed. Cir. 2021). But Intel isn’t a party to this
 one. In contrast, Intel was informed that “Qualcomm is not
 offering a covenant not to sue.” J.A. 4713. Although that
 refusal isn’t on its own “sufficient to create an actual con-
 troversy,” Prasco, LLC v. Medicis Pharm. Corp., 537 F.3d
 1329, 1341 (Fed. Cir. 2008), it reinforces the analogy to
 Grit, where the patentee declined to stipulate that it would
 not reassert its previous infringement allegations,
 957 F.3d at 1320 n.3.
     Moreover, Intel represents that it continues to sell the
 relevant products to Apple and at least one other customer,
 and that in doing so it must “address[] the ’043 patent and
 the risk of an infringement suit by Qualcomm.”
Case: 20-1664    Document: 103      Page: 7     Filed: 12/28/2021

 INTEL CORPORATION   v. QUALCOMM INCORPORATED                 7

 J.A. 4794–96; see J.A. 4785. 6 Because Intel’s risks trans-
 cend mere conjecture or hypothesis, see Spokeo, 578 U.S.
 at 339, we conclude that Intel has standing. See also Intel
 Corp. v. Qualcomm Inc., No. 20-1828, slip op. at 9–10
 (Fed. Cir. Dec. 28, 2021).
                               II
     On to the merits. We start with the parties’ dispute
 over the proper construction of the phrase “radio frequency
 input signal” in ’043 patent claims 17, 19, and 21. Before
 the Board, Intel said this phrase “should take its ordinary
 meaning of an input signal having a radio frequency.” Fi-
 nal Written Decision, at *7. Qualcomm disagreed, arguing
 that a skilled artisan reading the patent would have un-
 derstood the phrase to reference the radio frequency signal
 that is received before down-conversion: “a signal centered
 at a carrier frequency at which the signal was transmit-
 ted/received.” Id. at *6.
     The upshot is that Intel’s proposal (and not Qual-
 comm’s) covers a signal called the intermediate frequency
 (“IF”) signal in the two-stage “super heterodyne” architec-
 ture of prior-art reference Der. Unlike the one-stage “ho-
 modyne” architecture disclosed in the ’043 patent, receivers
 in super heterodyne architectures like Der demodulate a
 carrier signal in two stages: first to that IF signal, and then
 to baseband. Adopting Qualcomm’s proposal, the Board de-
 termined that Der didn’t anticipate claims 17, 19, and 21.
 Id. at *15.
     “We review claim construction based on intrinsic evi-
 dence de novo and review any findings of fact regarding ex-
 trinsic evidence for clear error.” SpeedTrack, Inc. v.

     6   Given Intel’s past and ongoing acts, Apple’s 2019
 acquisition of “the majority of Intel’s smartphone modem
 business” also doesn’t negate Intel’s standing.       See
 J.A. 4597–607.
Case: 20-1664     Document: 103      Page: 8   Filed: 12/28/2021

 8              INTEL CORPORATION   v. QUALCOMM INCORPORATED

 Amazon.com, Inc., 998 F.3d 1373, 1378 (Fed. Cir. 2021) (cit-
 ing Teva Pharms. USA, Inc. v. Sandoz, Inc., 574 U.S. 318,
 331–32 (2015)). Applying the “broadest reasonable inter-
 pretation” standard, 7 we affirm the Board’s construction.
      Claim terms are generally accorded their ordinary
 meaning—that is, their meaning to a skilled artisan at the
 time of the invention. Phillips v. AWH Corp., 415 F.3d
 1303, 1312–13 (Fed. Cir. 2005) (en banc). This approach
 “provides an objective baseline” for our inquiry. Id.
 at 1313. To that end, we consult the sources available to
 such artisans, including “the words of the claims them-
 selves, the remainder of the specification, the prosecution
 history, and extrinsic evidence concerning relevant scien-
 tific principles, the meaning of technical terms, and the
 state of the art.” Id. at 1314 (quoting Innova/Pure Water,
 Inc. v. Safari Water Filtration Sys., Inc., 381 F.3d 1111,
 1116 (Fed. Cir. 2004)). “Importantly,” skilled artisans are
 “deemed to read the claim term . . . in the context of the
 entire patent.” Id. at 1313. Even when seeking the “broad-
 est reasonable construction in light of the specification,”
 37 C.F.R. § 42.100(b) (2017), we still give words “their plain
 meaning” unless “inconsistent with the specification and
 prosecution history.” Arista Networks, Inc. v. Cisco Sys.,
 Inc., 908 F.3d 792, 796–98 (Fed. Cir. 2018) (rejecting con-
 struction as “overly broad, even under the broadest reason-
 able interpretation standard”). “Above all, the broadest
 reasonable interpretation must be reasonable in light of the
 claims and specification.” PPC Broadband, Inc. v. Corning
 Optical Commc’ns RF, LLC, 815 F.3d 747, 755 (Fed. Cir.
 2016).
     Considering the disputed phrase “radio frequency in-
 put signal” in a vacuum, both proposals have some appeal.

     7   Although that standard applies in this case, it has
 been superseded by the standard “used to construe the
 claim[s] in a civil action.” 37 C.F.R. § 42.100(b) (2018).
Case: 20-1664    Document: 103      Page: 9    Filed: 12/28/2021

 INTEL CORPORATION   v. QUALCOMM INCORPORATED                9

 From that vantage, it’s plausible that the disputed phrase
 equals the sum of its parts as Intel contends—a “signal”
 that is “within the range defined as the radio frequency
 spectrum” and is an “input to a circuit or component re-
 ceiver part.” E.g., Appellant’s Br. 25. But the phrase could
 just as easily mean something more specific, referring to a
 particular signal in the receiving process, as Qualcomm
 contends. Even without considering the surrounding claim
 language or the rest of the patent document, we note that
 it is not always appropriate to break down a phrase and
 give it an interpretation that is merely the sum of its parts.
 See FCC v. AT&T Inc., 562 U.S. 397, 406 (2011) (rejecting
 interpretation of “personal privacy” as “simply the sum of
 its two words”). In any event, and decisively, our inquiry
 is not limited to an analysis of the phrase in isolation. See,
 e.g., Hockerson-Halberstadt, Inc. v. Converse Inc., 183 F.3d
 1369, 1374 (Fed. Cir. 1999) (“Proper claim construction . . .
 demands interpretation of the entire claim in context, not
 a single element in isolation.”). “[A] term can be defined
 only in a way that comports with the instrument as a
 whole.” Markman v. Westview Instruments, Inc., 517 U.S.
 370, 389 (1996).
      We therefore continue by examining the surrounding
 claim language. Phillips, 415 F.3d at 1314. Claim 17 below
 (emphasis added) has a tripartite structure: it describes
 (a) the signal received, (b) the signal output, and (c) the
 switching functionality:
     17. A method comprising:
     (a) receiving a radio frequency input signal onto a
     source lead of a first transistor and onto a source
     lead of a second transistor;
     (b) outputting a baseband signal from a drain lead
     of the first transistor, wherein the baseband signal
     has a current with a magnitude; and
Case: 20-1664     Document: 103      Page: 10     Filed: 12/28/2021

  10            INTEL CORPORATION   v. QUALCOMM INCORPORATED

       (c) increasing the magnitude of the current of the
       baseband signal by coupling the drain lead of the
       first transistor to a drain lead of the second tran-
       sistor, wherein the drain lead of the first transistor
       is coupled to the drain lead of the second transistor
       by closing a switch that is coupled to both the drain
       lead of the first transistor and the drain lead of the
       second transistor.
      This language points in favor of Qualcomm’s reading
  adopted by the Board. First, if the “radio frequency input
  signal” refers to just any radio frequency signal that is an
  input, then the word “input” makes no contribution to the
  claim. Omitting it would change nothing, given the mixer’s
  “receiving” of the signal “onto a source lead.” See Antonin
  Scalia & Bryan A. Garner, Reading Law 176 (2012) (“Be-
  cause legal drafters should not include words that have no
  effect, courts avoid a reading that renders some words al-
  together redundant.”); see also Intel, No. 20-1828, slip op.
  at 13 (collecting cases). Second, part (a) of the claim doesn’t
  strictly parallel part (b), raising the question why part (a)
  doesn’t instead say “inputting a radio frequency signal” if
  indeed “a radio frequency input signal” is just a radio fre-
  quency signal that is input. These linguistic clues suggest
  that “radio frequency input signal,” to the relevant audi-
  ence, refers to the signal entering the device as a whole, not
  (as Intel proposes) to any radio frequency signal entering
  any component.
      The specification provides further support for the
  Board’s reading. It consistently and repeatedly uses “radio
  frequency input signal” to reference the carrier frequency
  signal received at the antenna, amplified by the low-noise
  amplifiers, and received at the mixer’s transistors for direct
  down-conversion to baseband. For example, Figure 2 (see
  annotated versions above) shows a signal 32 that’s received
  at antenna 16 and that, Qualcomm has not disputed, is the
  carrier frequency signal sent over the air. Indeed, the pa-
  tent in the context of Figure 1 expressly calls signal 32 “the
Case: 20-1664     Document: 103       Page: 11     Filed: 12/28/2021

  INTEL CORPORATION    v. QUALCOMM INCORPORATED                 11

  carrier signal” that is “downconvert[ed]” to “baseband.” Id.
  at col. 5 ll. 43–58. 8 And then in its subsequent discussion
  of Figure 2, the patent explains that “[r]adio frequency in-
  put signal 32 is amplified by LNAs 17–19 and then received
  onto the source leads of transistors 39–40,” after which
  point “a baseband signal current 84 is output from the
  drain lead [of the] first transistor 39.” Id. at col. 10
  l. 64–col. 11 l. 8 (emphasis added); see also id. at col. 3
  ll. 52–58 (similar); id. at col. 3 ll. 18–30 (similar). That dis-
  cussion also references and parallels the flowchart of Fig-
  ure 11, which as its first step recites “receive a radio
  frequency input signal onto a source lead of a first transis-
  tor and onto a source lead of a second transistor” followed
  by direct down-conversion of that signal to baseband. Id.
  at Fig. 11 (capitalization normalized). We find this con-
  sistency compelling.
      Intel objects that the Board’s construction limits the or-
  dinary meaning of the claims to the patent’s embodiments,
  an approach we’ve “expressly rejected.” Info-Hold, Inc. v.
  Applied Media Techs. Corp., 783 F.3d 1262, 1267 (Fed. Cir.
  2015). Just because the patent doesn’t “specifically use the
  term ‘RF input signal’ to describe the input into a second-
  stage mixing circuit,” Intel says, that doesn’t limit the pa-
  tent “to homodyne receiver architectures” and exclude “su-
  per heterodyne” ones. Appellant’s Br. 26–27. But this
  presupposes the point it purports to prove. It takes for
  granted that Intel has the ordinary meaning right. In this
  case, however, the question is what the contextually correct
  meaning is, not whether anything affirmatively limits an
  undisputed ordinary meaning.

      8   Elsewhere, the patent also suggests that the inven-
  tion could be used in reverse to “modulate baseband data”
  up to a radio frequency signal “transmitted from the wire-
  less device” (i.e., a carrier signal). ’043 patent col. 11
  ll. 56–61 (emphasis added).
Case: 20-1664     Document: 103      Page: 12   Filed: 12/28/2021

  12            INTEL CORPORATION   v. QUALCOMM INCORPORATED

       And although the patent doesn’t disclose any super het-
  erodyne embodiments, it does (once) mention intermediate
  frequencies in a way that favors the Board’s construction.
  As background, it states: “Receivers for wireless communi-
  cation systems typically require low noise amplifiers
  (LNAs) followed by double-balanced mixers to pre-amplify
  incoming signals and to down-convert those signals to an
  appropriate intermediate frequency (IF) or baseband fre-
  quency.” ’043 patent col. 1 ll. 11–15. This statement
  doesn’t describe an intermediate frequency as a species of
  “radio frequency input signal.” Rather, it uses a distinct
  label, “intermediate frequency (IF).” Generally speaking,
  “[a] word or phrase is presumed to bear the same meaning
  throughout a text; a material variation in terms suggests a
  variation in meaning.” Scalia & Garner, supra, at 170; see
  PPC, 815 F.3d at 752 (noting this canon is “employed in
  both statutory interpretation and claim construction”).
  Here we discern such a material variation, suggesting that
  “intermediate frequency (IF)” means something different
  from “radio frequency input signal.”
      Further, beyond indicating a material variation in
  terms, the structure of the patent’s “IF” passage also hints
  that an intermediate frequency isn’t covered by the claimed
  “radio frequency input signal.” By describing both the “in-
  termediate frequency (IF)”and the “baseband frequency” as
  results of down-converting “incoming” signals, the passage
  parallels the claim’s structure—which reflects “receiving”
  an incoming “radio frequency input signal” and outputting
  the result of down-conversion: a “baseband signal.” Id.
  at claim17. As Intel’s counsel observed, the claim structure
  “juxtapos[es]” the “radio frequency input signal” with the
  “baseband.” Oral Arg. at 2:30–50, No. 20-1664. 9 There-
  fore, although the passage may not explicitly distinguish

       9  https://oralarguments.cafc.uscourts.gov/de-
  fault.aspx?fl=20-1664_10072021.mp3.
Case: 20-1664    Document: 103       Page: 13   Filed: 12/28/2021

  INTEL CORPORATION   v. QUALCOMM INCORPORATED              13

  IF from RF, see Oral Arg. at 30:15–32:37; Final Written De-
  cision, at *7, it treats intermediate frequencies as akin to
  baseband signals—which map to the “outputting” phrase
  of part (b) rather than the “radio frequency input signal” of
  part (a).
       Indeed, this framing illuminates how, rather than be-
  ing limited to homodyne architectures as Intel suggests,
  the Board’s construction can indeed cover super hetero-
  dyne architectures. The first stage would “receiv[e]” a “ra-
  dio frequency input signal” that, per the Board’s
  construction, is centered at a carrier frequency, and the
  second stage would “output[]” a baseband signal. Id. at
  claim 17. In between would be the work of down-conver-
  sion, first to an intermediate frequency and then to the
  “output[]” baseband signal of the claim. Id. The effect of
  the Board’s construction is not, therefore, that all super
  heterodyne architectures are excluded, but more modestly
  that the intermediate signal of such an architecture simply
  isn’t the “radio frequency input signal” of the claims.
       In sum, while Intel’s interpretation may have superfi-
  cial appeal, Qualcomm’s better reflects the usage of “radio
  frequency input signal” in the intrinsic record. It prevents
  the word “input” from being redundant in the claim and
  comports with the claim’s tripartite structure. And it re-
  flects the specification’s repeated use of the disputed
  phrase to reference incoming carrier signals before down-
  conversion. See Arista, 908 F.3d at 798 (construing “broad-
  cast” to mean “a transmission to one or more devices using
  a multicast address” based on “the specification’s con-
  sistent focus on broadcasting via a multicast address”). Be-
  cause the Board’s construction gives effect to the
  contextually appropriate meaning of “radio frequency in-
  put signal,” we affirm it.
                               III
      Next we turn to obviousness, addressing first the orig-
  inally challenged claims and second the substitute claims.
Case: 20-1664     Document: 103      Page: 14    Filed: 12/28/2021

  14            INTEL CORPORATION   v. QUALCOMM INCORPORATED

  The ultimate judgment of obviousness under 35 U.S.C.
  § 103 is a legal determination based on underlying factual
  inquiries. “[T]he scope and content of the prior art are to
  be determined; differences between the prior art and the
  claims at issue are to be ascertained; and the level of ordi-
  nary skill in the pertinent art resolved.” Graham v. John
  Deere Co. of Kan. City, 383 U.S. 1, 17 (1966). Also, “[s]uch
  secondary considerations as commercial success, long felt
  but unsolved needs, failure of others, etc., might be utilized
  to give light to the circumstances surrounding the origin of
  the subject matter sought to be patented.” Id. at 17–18.
      In cases where “the question is whether a patent claim-
  ing the combination of elements of prior art is obvious,” “it
  can be important to identify a reason that would have
  prompted a person of ordinary skill in the relevant field to
  combine the elements in the way the claimed new inven-
  tion does.” KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398,
  417–18 (2007). That, too, is a factual inquiry. ZUP, LLC
  v. Nash Mfg., Inc., 896 F.3d 1365, 1371 (Fed. Cir. 2018).
  We review the Board’s factual findings for substantial evi-
  dence and its legal conclusions de novo. Donner Tech., LLC
  v. Pro Stage Gear, LLC, 979 F.3d 1353, 1358 (Fed. Cir.
  2020).
      Both obviousness issues on appeal involve “whether
  there was an apparent reason to combine” the prior-art el-
  ements. KSR, 550 U.S. at 418. In KSR (decided over 10
  years ago now), the Supreme Court rejected the “teaching,
  suggestion, or motivation” (“TSM”) test that we inherited
  from our predecessor court. Id. at 407, 418. Under that
  test, “a patent claim [was] only proved obvious if some mo-
  tivation or suggestion to combine the prior art teachings
  [could] be found in the prior art, the nature of the problem,
  or the knowledge of a person having ordinary skill in the
  art.” Id. at 407 (cleaned up). The Court acknowledged that
  the TSM test “captured a helpful insight” by addressing the
  intuition that “a patent composed of several elements is not
  proved obvious merely by demonstrating that each of its
Case: 20-1664    Document: 103      Page: 15     Filed: 12/28/2021

  INTEL CORPORATION   v. QUALCOMM INCORPORATED               15

  elements was, independently, known in the prior art.” Id.
  at 418. “Helpful insights, however, need not become rigid
  and mandatory formulas.” Id. at 419. Therefore, the Court
  instead adopted an “expansive and flexible approach.” Id.
  at 415. No longer would “[t]he obviousness analysis . . . be
  confined by a formalistic conception of the words teaching,
  suggestion, and motivation, or by overemphasis on the im-
  portance of published articles and the explicit content of
  issued patents.” Id. at 419.
       We assess Intel’s challenges to the Board’s obviousness
  determinations under the principles in KSR. We reject the
  first, (A) that the Board didn’t satisfactorily explain why a
  skilled artisan would not have combined Der with Valla.
  We accept the second, (B) that a skilled artisan would have
  had reason to combine Burgener with Der, because the
  Board’s decision rejecting that rationale is not supported
  by substantial evidence.
                                A
      We begin with the Board’s determination that Intel
  didn’t prove claims 6, 17–19, and 21 were obvious in light
  of Der and Valla (nor, for the same reason, substitute
  claims 27, 28, and 31 in light of Der, Valla, and Burgener).
       Before the Board, Intel argued that a skilled artisan
  would have “modified Valla to include two parallel passive
  mixers having outputs coupled by a gain control block con-
  sisting of switches . . . to achieve the advantages of Der and
  Valla.” Final Written Decision, at *19. Qualcomm disa-
  greed, reasoning that “the transistors from Der would im-
  pair the low impedance that Valla seeks for its amplifier.”
  Id. at *20. The Board agreed with Qualcomm. As the
  Board explained, “Valla discusses the importance of a pas-
  sive mixer with a ‘low impedance’ load” for obtaining the
  system’s benefits, calling this a “key feature.” Id. at *21.
  Along the way, it rejected Intel’s riposte: that in “triode
  mode” Der’s transistors “would have very low impedance
Case: 20-1664     Document: 103      Page: 16    Filed: 12/28/2021

  16            INTEL CORPORATION   v. QUALCOMM INCORPORATED

  and would have no adverse impact” on Valla’s circuit. Id.
  at *20 (quoting J.A. 1834 ¶ 61).
      On appeal, Intel doesn’t argue that the Board’s deter-
  mination lacks substantial-evidence support. 10 Rather, it
  says the Board didn’t “apply the proper mode of legal anal-
  ysis [of] weigh[ing] the putative disadvantage . . . against
  the combination’s undisputed benefits.” Reply Br. 18. As
  an initial matter, we agree that “simultaneous advantages
  and disadvantages . . . do[] not necessarily obviate motiva-
  tion to combine.” Medichem, S.A. v. Rolabo, S.L., 437 F.3d
  1157, 1165 (Fed. Cir. 2006). In KSR itself, for example, ev-
  idence indicating that a prior-art product was “bulky, com-
  plex, and expensive” wasn’t on its own enough to dismiss it
  as “too flawed to upgrade.” 550 U.S. at 425–26. But here
  we conclude the Board’s analysis is adequate, applying the
  proper standard.
       Specifically, the Board noted that Intel’s expert didn’t
  disagree with Qualcomm’s expert as to what would happen
  in the non-triode modes. Final Written Decision, at *21–22.
  The thrust of both experts’ testimony, the Board explained,
  is that “although there are some conditions . . . that result
  in Der’s transistor M9 operating in the triode mode . . . over
  most of the operating conditions the transistor is in a dif-
  ferent mode.” Id. at *22. Therefore, the Board concluded,
  a skilled artisan would have lacked motivation to combine
  Valla with Der because that “would impair Valla’s need for
  low impedance during the majority of operation.” Id. (em-
  phasis added). On this record, we’re satisfied that the
  Board weighed the competing evidence regarding the

       10  Oral Arg. at 14:06–32 (Q: “So you’re not making a
  substantial-evidence challenge?” A: “No your Honor, we’re
  not.”); Oral Arg. at 15:34–49 (Q: “So, just to be clear, if we
  don’t find that the Board applied the incorrect legal test for
  obviousness, you’re not saying their conclusion lacks sub-
  stantial evidence?” A: “That is correct, your Honor.”).
Case: 20-1664    Document: 103      Page: 17    Filed: 12/28/2021

  INTEL CORPORATION   v. QUALCOMM INCORPORATED                17

  relevant tradeoffs and concluded, based on the stated im-
  portance of low impedance as “key” to Valla, that negating
  this benefit during “the majority of the operation” would
  have outweighed any reason to combine. 11
                               B
       Last, we conclude that substantial evidence does not
  support the Board’s determination that a skilled artisan
  would have lacked reason to combine Der with Burgener
  (in the Der-Burgener-Razavi combination) to achieve sub-
  stitute claims 27, 28, and 31. Those claims depend on sub-
  stitute claim 26, which adds a single limitation to claim 1
  (additions italicized; deletions bracketed):
      26. (Proposed Substitute for Claim 1) A device com-
      prising:
      (a) an amplifier having an output lead;
      (b) a first transistor having a source lead, a drain
      lead and a gate lead;
      (c) a second transistor having a source lead, a drain
      lead and a gate lead, wherein the output lead of the
      amplifier is coupled to the source lead of the first

      11  The Board also said Intel relied “at least in part[]
  on impermissible hindsight” because it “provide[d] no sup-
  port—whether from Valla, Der, or some other source” for a
  benefit also identified in the patent. Final Written Deci-
  sion, at *22. We’re skeptical that this necessarily trans-
  lates to hindsight. There’s another possibility: that
  without “seek[ing] out precise teachings,” Intel merely took
  “account of the inferences and creative steps” a skilled ar-
  tisan would employ. KSR, 550 U.S. at 418. At any rate,
  Intel doesn’t press a substantial-evidence challenge (see
  above), so we affirm the Board’s Der-Valla determination.
Case: 20-1664      Document: 103      Page: 18     Filed: 12/28/2021

  18            INTEL CORPORATION    v. QUALCOMM INCORPORATED

       transistor and to the source lead of the second tran-
       sistor; [[and]]
       (d) a first switch, wherein the drain lead of the first
       transistor is coupled to the drain lead of the second
       transistor through the first switch when the first
       switch is closed, and wherein an oscillating signal
       is present on the gate lead of the first transistor
       and on the gate lead of the second transistor; and
       (e) a second switch, wherein the drain lead of the
       second transistor is coupled to ground through the
       second switch when the second switch is closed.
  J.A. 3763 (alterations in original).
       Intel relied on Burgener to disclose this added limita-
  tion. Burgener describes as background a “prior art
  switch” that includes “a switching transistor” and “a shunt-
  ing transistor.” J.A. 1873. Via that switch, Burgener
  states, “RF signals are either routed from an RF input
  node” to “an RF output node,” or else are “shunted to
  ground through the shunting transistor M2 7.” J.A. 1873.
  From there, Intel argued that a skilled artisan would have
  had reason to combine Burgener’s switch with Der’s re-
  ceiver architecture (and the teachings of Razavi)—render-
  ing these substitute claims unpatentable. Intel’s asserted
  rationale proceeds in two steps. First, a skilled artisan
  would have sought to improve energy efficiency by turning
  off a portion of Der’s circuit when not in use. Second, doing
  so would have triggered a known problem to which Bur-
  gener’s switch was a predictable solution.
       The Board disagreed for three reasons: (1) that Intel’s
  energy-efficiency theory was too generic, (2) that Burgener
  described the switch as prior art with shortcomings, and
  (3) that the combination would render Der unsuitable for
  its intended purpose. Under applicable legal principles,
  none of the Board’s reasons are supported by substantial
  evidence.
Case: 20-1664    Document: 103      Page: 19    Filed: 12/28/2021

  INTEL CORPORATION   v. QUALCOMM INCORPORATED              19

                               1
      First, we evaluate whether substantial evidence sup-
  ports the Board’s conclusion that Intel’s energy-efficiency
  rationale was deficient because, in the Board’s view, it was
  “nothing more than a generic reason to make something
  better” and “[i]ncreasing energy efficiency is no more than
  a generic concern that exists in many, if not all, electronic
  devices.” Final Written Decision, at *27 (emphasis added).
  For support, the Board looked to ActiveVideo Networks,
  Inc. v. Verizon Communications, Inc., in which we rejected
  a rationale premised on the following testimony:
      The motivation to combine would be because you
      wanted to build something better. You wanted a
      system that was more efficient, cheaper, or you
      wanted a system that had more features, makes it
      more attractive to your customers, because by com-
      bining these two things you could do something
      new that [you] hadn’t been able to do before.
  694 F.3d 1312, 1328 (Fed. Cir. 2012). That decision, how-
  ever, didn’t denounce energy efficiency as per se insuffi-
  cient as the Board’s decision suggests. Such a rationale is
  not inherently suspect merely because it’s generic in the
  sense of having broad applicability or appeal. Quite the
  opposite. Even before KSR, we held that because such im-
  provements are “technology-independent,” “universal,” and
  “even common-sensical,” “there exists in these situations a
  motivation to combine prior art references even absent any
  hint of suggestion in the references themselves.” DyStar
  Textilfarben GmbH v. C.H. Patrick Co., 464 F.3d 1356,
  1368 (Fed. Cir. 2006) (emphasis added) (referencing an
  “implicit motivation to combine” to make a device “more de-
  sirable, for example because it is stronger, cheaper,
  cleaner, faster, lighter, smaller, more durable, or more ef-
  ficient”); see KSR, 550 U.S. at 421 (quoting DyStar,
  464 F.3d at 1367).
Case: 20-1664     Document: 103      Page: 20   Filed: 12/28/2021

  20            INTEL CORPORATION   v. QUALCOMM INCORPORATED

      Of course, “generic” might also have a different sense:
  conclusory. Certainly, “[c]onclusory expert testimony does
  not qualify as substantial evidence,” TQ Delta, LLC v.
  Cisco Sys., Inc., 942 F.3d 1352, 1358–59 (Fed. Cir. 2019),
  as demonstrated in ActiveVideo. But unlike ActiveVideo,
  this isn’t a case “where the motivation of increased effi-
  ciency is asserted so generically as to be legally insuffi-
  cient.” Huawei Techs. Co. v. Iancu, 813 F. App’x 505, 510
  (Fed. Cir. 2020) (describing ActiveVideo). The testimony in
  ActiveVideo bore “no relation to any specific combination of
  prior art elements . . . from specific references” and didn’t
  explain why a skilled artisan would have combined them
  “in the way the claimed invention does,” 694 F.3d at 1328,
  but here Intel’s expert indicated precisely how and why a
  skilled artisan would have combined the references.
      Recall that Der has a super heterodyne architecture.
  Der’s second stage “employs two parallel mixers . . . a main
  mixer and a variable-gain mixer,” along with “a gain con-
  trol circuit at the output of the variable-gain mixer.” Ap-
  pellee’s Br. 42 (cleaned up). According to Intel’s expert, a
  skilled artisan “would have recognized that, in cases where
  gain control is not required (e.g. when the gain of the ‘main
  mixer’ alone is sufficient), it would have been advantageous
  to disable the variable-gain mixer to save power.”
  J.A. 1840 ¶ 70 (capitalization normalized). Specifically,
  such an artisan “would have combined the mixer circuit of
  Der Figure 9(b) with the shunt transistor M2 7 of
Case: 20-1664    Document: 103      Page: 21    Filed: 12/28/2021

  INTEL CORPORATION   v. QUALCOMM INCORPORATED              21

  Burgener,” as shown in Intel’s annotated Figure 9(b) below
  (which incorporates Burgener’s switches into Der’s circuit):

  J.A. 3802. As Intel’s expert explained, “one way to disable
  the variable-gain mixer in Der would be to turn off transis-
  tor switches M7-M10 to shut off the input signal into the
  gain control circuit, by setting Der’s VG+ and VG- to a low
  voltage (e.g. 0V).” Id. (capitalization normalized and em-
  phasis omitted). This explanation for the how isn’t re-
  motely conclusory. J.A. 1840 ¶ 70.
      Nor is Intel’s explanation for the why. For one thing,
  Intel’s expert pointed out that Der expressly highlights
  power consumption as a consideration. J.A. 1840 ¶ 70 (cit-
  ing J.A. 1178 (quantifying power consumption)). For an-
  other, Intel’s expert explained that the idea of “disabl[ing]
  the variable-gain mixer to save power” flows directly from
  the observation that the variable-gain mixer isn’t always
  needed. J.A. 1840 ¶ 70 (capitalization normalized). That,
  in turn, follows from Der’s statement that the “gain-control
  circuit . . . can add, subtract, or null signal currents from
  the variable-gain mixer.” J.A. 1840 ¶ 70 (quoting J.A. 1182
  (emphasis added)). In Intel’s words, “the gain-control cir-
  cuit will block all, some, or none of the output signal cur-
  rent from the variable-gain mixer, whichever is
  appropriate to achieve the desired level of gain.” Appel-
  lant’s Br. 10. Consistent with that observation, Qual-
  comm’s expert acknowledged at least one scenario in which
Case: 20-1664     Document: 103      Page: 22   Filed: 12/28/2021

  22            INTEL CORPORATION   v. QUALCOMM INCORPORATED

  “the output of the variable gain mixer would not contribute
  anything to the output.” J.A. 1909–10. And if that weren’t
  enough, Der expressly contemplates the idea of turning off
  unused circuits. As Intel noted to the Board, “although Der
  does not expressly describe turning off the variable gain
  mixer, it does describe turning off the calibration circuit.”
  Final Written Decision, at *26.
      The facts of KSR are instructive here. The patent in
  KSR claimed a design for an adjustable pedal with an elec-
  tronic sensor mounted on its fixed pivot point. 550 U.S.
  at 425. This, the Court concluded, was an obvious improve-
  ment to a prior-art adjustable pedal (disclosed in the Asano
  reference) with a sensor (like those disclosed in other ref-
  erences). Id. at 425–26. Just as KSR examined whether a
  skilled artisan “would have seen a benefit to upgrading As-
  ano with a sensor,” Intel argued that a skilled artisan
  would have “seen a benefit” to upgrading Der with Bur-
  gener’s switch. Id. at 424. Intel explained that doing so
  would improve energy efficiency for situations in which the
  variable-gain mixer is not in use. Far from being conclu-
  sory, Intel “fit the teachings of multiple patents together
  like pieces of a puzzle.” Id. at 420. The Board’s critique of
  this rationale as impermissibly “generic” is not supported
  by substantial evidence.
                               2
      The Board’s second complaint about Intel’s rationale is
  that it relied on the prior-art switch described as back-
  ground in Burgener, which Burgener criticizes and pur-
  ports to improve. Under the applicable legal standard,
  substantial evidence does not support rejecting Intel’s ra-
  tionale on this ground.
      Before the Board, Intel argued that a skilled artisan
  would have used Burgener’s prior-art switch to solve a
  known problem—the “feedthrough problem”—that was an
  expected negative consequence of disabling Der’s variable-
  gain mixer. As Intel’s expert explained, “due to the finite
Case: 20-1664    Document: 103      Page: 23     Filed: 12/28/2021

  INTEL CORPORATION   v. QUALCOMM INCORPORATED               23

  isolation of the transistor switches M7-M10, even when
  those transistors are off, some of the local oscillator (‘LO’)
  signal (applied to the gates of transistors M3A-M6A) would
  still feed through and appear at the output of the variable-
  gain mixer, degrading the signal quality.” J.A. 1840 ¶ 70
  (capitalization normalized). Using the prior-art switch of
  Burgener, with its “shunting transistor,” Intel’s expert ex-
  plained, would “allow for improved signal quality . . . by
  shunting any LO feedthrough current to ground.”
  J.A. 1840 ¶ 71. Intel’s expert opined, accordingly, that this
  combination “would have involved nothing more than use
  of a known technique (adding a shunt switch to an RF
  switch) to improve a similar device (e.g., the overall mixer
  of Der) in the same way (providing a shunt path to ground
  to improve isolation).” J.A. 1840 ¶ 72.
       Here again, KSR is our guide. In KSR, a key question
  was “where to attach the sensor” to Asano’s pedal—specif-
  ically, whether a skilled artisan “starting with Asano
  would have found it obvious to put the sensor on a fixed
  pivot point.” 550 U.S. at 424–25. One prior-art reference
  taught “putting the sensor on the pedal device.” Id. at 425.
  Another (Smith) taught putting it “not on the pedal’s foot-
  pad but instead on its support structure,” and a third
  (Rixon) noted that a “wire-chafing” problem arises when
  placing a sensor on a moving part of a pedal. Id. From this
  constellation of references, a skilled artisan “would know
  to place the sensor on a nonmoving part of the pedal struc-
  ture” and that “[t]he most obvious nonmoving point on the
  structure from which a sensor can easily detect the pedal’s
  position is a pivot point” like the one in Asano—arriving at
  the claimed invention. Id.
      Just as the known wire-chafing problem in KSR had an
  obvious solution (placing the sensor on a nonmoving point),
  so too here undisputed evidence shows that incorporating
  Burgener’s switch was an “obvious solution” to the “known
  [feedthrough] problem.” Id. at 420; see generally J.A. 1873
  (Burgener discussing feedthrough problem and shunting
Case: 20-1664     Document: 103      Page: 24    Filed: 12/28/2021

  24            INTEL CORPORATION   v. QUALCOMM INCORPORATED

  solution). There is therefore little difference between this
  circumstance and the one in KSR, where “the prior art was
  replete with patents indicating that a fixed pivot point was
  an ideal mount for a sensor.” 550 U.S. at 420. Intel’s ex-
  pert explained that combining Der with Burgener “results
  in the LO feedthrough being reduced,” and “predictable re-
  sults and benefits are obtained as described in Burgener.”
  J.A. 1840 ¶ 72 (emphasis omitted). To use KSR’s words,
  this is “the predictable use of prior art elements according
  to their established functions.” 550 U.S. at 417.
      The Board saw things differently. Noting that “Bur-
  gener discusses problems associated with [the] prior art de-
  signs” (namely “insertion loss, switch isolation, and switch
  compression”), and that for that reason Burgener “provides
  improvements,” the Board reasoned that although a skilled
  artisan “could have selected the less effective prior art RF
  switches over the improved switches that are the subject of
  Burgener, [Intel] has not sufficiently demonstrated” why
  such an artisan “would have selected using elements from
  the less effective prior art designs.” Final Written Decision,
  at *27. “Without such an explanation,” the Board said, “the
  only reasonable inference is that [Intel] focused on Bur-
  gener’s description of prior art switches using impermissi-
  ble hindsight.” Id. Not so. Our caselaw is clear. It’s not
  necessary to show that a combination is “the best option,
  only that it be a suitable option.” PAR Pharm., Inc. v. TWI
  Pharms., Inc., 773 F.3d 1186, 1197–98 (Fed. Cir. 2014).
  And “if a technique has been used to improve one device,
  and a person of ordinary skill in the art would recognize
  that it would improve similar devices in the same way, us-
  ing the technique is obvious unless its actual application is
  beyond his or her skill.” KSR, 550 U.S. at 417. That’s what
  we have here. Given the facts and reasoning of KSR, it is
  readily apparent that the Board’s hindsight inference lacks
  substantial evidence.
       Qualcomm describes Intel’s theory as fixing a “problem
  of their own making.” Appellee’s Br. 52. But the same can
Case: 20-1664    Document: 103      Page: 25    Filed: 12/28/2021

  INTEL CORPORATION   v. QUALCOMM INCORPORATED              25

  be said of the known wire-chafing problem in KSR, which
  arose by virtue of combining an adjustable pedal with an
  electronic sensor. 550 U.S. at 425. As the KSR Court
  noted, “[i]n automotive design, as in many other fields, the
  interaction of multiple components means that changing
  one component often requires the others to be modified as
  well.” Id. at 424. So too here. Like modifying Asano in a
  way that avoided the wire-chafing problem in KSR, modi-
  fying Der with Burgener in a way that avoids the feed-
  through problem doesn’t neutralize Intel’s rationale.
                               3
      Last, the Board rejected Intel’s asserted rationale be-
  cause “powering off the variable gain mixer would have re-
  sulted in the circuit not being suitable for its intended
  purpose.” Final Written Decision, at *27. In so concluding,
  the Board explained that “Der describes two modes: a cali-
  bration mode and an operating mode” and then reasoned
  that “it does not logically flow that because the calibration
  mode is only used for calibration, other parts of the circuit
  that are intended to be used during normal operation
  would be turned off during normal operation.” Id. That,
  apparently, is because “nothing in Der suggests turning off
  any part of the functional circuit elements, let alone the
  ‘important’ variable gain mixer.” Id.
      Once again, the Board’s decision lacks substantial evi-
  dence under the standards articulated in KSR. Intel’s ob-
  viousness rationale isn’t defective merely because “nothing
  in Der suggests” it. Id. But even if that were the correct
  test, which it is not, portions of Der do suggest this ra-
  tionale—suggesting that power consumption was a consid-
  eration, that circuits may be turned off when not in use,
  and that the variable-gain mixer is not always in use, as
  detailed above. See generally J.A. 1840 ¶ 70.
      Further, the intended purpose of Der does not control.
  “Common sense teaches . . . that familiar items may have
  obvious uses beyond their primary purposes.” KSR,
Case: 20-1664     Document: 103      Page: 26   Filed: 12/28/2021

  26            INTEL CORPORATION   v. QUALCOMM INCORPORATED

  550 U.S. at 420. Indeed, one of the points on which the
  Court in KSR disagreed with our decision below in that
  case was our reliance on the primary purposes of prior-art
  references. We had pointed out that Asano “was designed
  to solve the constant ratio problem,” that Rixon “suffered
  from the problem of wire chafing but was not designed to
  solve it,” and that Smith “did not relate to adjustable ped-
  als and did not necessarily go to the issue of motivation to
  attach the electronic control on the support bracket of the
  pedal assembly.” Id. at 414 (internal quotation marks
  omitted). That was misguided. “Regardless of Asano’s pri-
  mary purpose, the design provided an obvious example of
  an adjustable pedal with a fixed pivot point” such that
  “[t]he idea that a designer hoping to make an adjustable
  electronic pedal would ignore Asano because Asano was de-
  signed to solve the constant ratio problem makes little
  sense.” Id. at 420–21. Finally, the Board didn’t explain
  how disabling Der’s variable-gain mixer would hinder its
  purpose in use cases where “achieving the ‘desired output’
  requires that the output of the variable-gain mixer be
  ‘null[ed]’—a possibility that Der itself contemplates.” Ap-
  pellant’s Br. 45–46 (quoting J.A. 1182) (alteration in origi-
  nal).
      Accordingly, the Board’s analysis lacks substantial ev-
  idence under KSR. We vacate the Board’s decision as to
  substitute claims 27, 28, and 31 and remand with instruc-
  tions that Intel demonstrated sufficient reason for combin-
  ing Der with Burgener. The Board should resolve any
  remaining disputes regarding that combination on re-
  mand. E.g., Appellee’s Br. 52 n.11.
                         CONCLUSION
      We have considered the parties’ remaining arguments
  but find them unpersuasive. We affirm the Board’s claim
  construction and decision as to claims 6, 17–19, and 21. We
  vacate the Board’s determination as to substitute
  claims 27, 28, and 31 and remand for further proceedings.
Case: 20-1664    Document: 103      Page: 27   Filed: 12/28/2021

  INTEL CORPORATION   v. QUALCOMM INCORPORATED            27

    AFFIRMED-IN-PART, VACATED-IN-PART, AND
                  REMANDED
                            COSTS
  The parties shall bear their own costs.