Parkervision, Inc. v. Qualcomm Incorporated, Qualcomm Atheros, Inc.

United States Court of Appeals
for the Federal Circuit
______________________
PARKERVISION, INC.,
Plaintiff-Appellant
v.
QUALCOMM INCORPORATED, QUALCOMM
ATHEROS, INC.,
Defendants-Appellees
______________________
2022-1755, 2024-2221
______________________
Appeal from the United States District Court for the
Middle District of Florida in No. 6:14-cv-00687-PGB-LHP,
Judge Paul G. Byron.
______________________
Decided: September 6, 2024
______________________
J OSHUA WRIGHT BUDWIN, McKool Smith, P.C., Austin,
TX, argued for plaintiff-appellant. Also represented by
MATTHEW CAMERON, J OEL L ANCE T HOLLANDER, R AYMOND
MITCHELL VERBONCOEUR; K EVIN L. B URGESS , Marshall,
TX.
EAMONN G ARDNER , Cooley LLP, Denver, CO, argued for
defendants-appellees. Also represented by MATTHEW J.
BRIGHAM , D ENA CHEN , J EFFREY S. K ARR, BENJAMIN S. L IN,
P RIYA B. VISWANATH , Palo Alto, CA; STEPHEN SMITH ,
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PARKERVISION, INC. v. QUALCOMM INCORPORATED 2
Washington, DC; MICHAEL EDWARD L OCKAMY , Bedell,
Dittmar, DeVault, Pillans & Coxe, P.A., Jacksonville, FL.
______________________
Before L OURIE, MAYER, and STARK, Circuit Judges.
STARK, Circuit Judge.
More than nine years ago, we affirmed a judgment as
a matter of law (“JMOL”) of non-infringement in a patent
infringement action brought by ParkerVision, Inc. (“Par-
kerVision”) against Qualcomm Inc. (“Qualcomm”) relating
to wireless communications technology. ParkerVision, Inc.
v. Qualcomm Inc., 621 F. App’x 1009 (Fed. Cir. 2015) (“Par-
kerVision I”). ParkerVision also filed a second infringe-
ment suit against Qualcomm on different but related
patents. The latter case, which we will refer to as the “2014
Action,” concluded with the district court granting Qual-
comm’s motion for summary judgment of non-infringement
based on collateral estoppel arising from ParkerVision I.
ParkerVision, Inc. v. Qualcomm Inc., 2022 WL 1230505
(M.D. Fla. Mar. 22, 2022). The district court also granted
Qualcomm’s motions to exclude certain testimony Par-
kerVision had proposed to present through its validity and
infringement experts (“Daubert motions”). ParkerVision
now appeals the disposition of the 2014 Action. We vacate
the judgment of non-infringement, reverse the exclusion of
testimony, and remand for further proceedings.
I
The litigation saga between ParkerVision and Qual-
comm dates back to 2011, when ParkerVision sued Qual-
comm in the United States District Court for the Middle
District of Florida, alleging infringement of its patented
technology relating to “down-converting” electromagnetic
signals (the “2011 Action”). As we described in our Par-
kerVision I decision – which ended the 2011 Action by af-
firming the district court’s grant of JMOL of non-
infringement – “‘[d]own-converting’ refers to converting a
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PARKERVISION, INC. v. QUALCOMM INCORPORATED 3
modulated high-frequency electromagnetic signal into a
low-frequency or ‘baseband’ signal in an electronic device
such as a wireless receiver.” ParkerVision I, 621 F. App’x
at 1011. ParkerVision’s down-converting system uses a
technique called “energy sampling,” which “differs from the
technique of ‘voltage sampling,’ which was used in conven-
tional down-converting systems.” Id. As depicted in Figure
82A of one of the patents at issue in the 2011 Action, U.S.
Patent No. 6,061,551 (“’551 patent”), the circuit of Par-
kerVision’s down-converting system “consists of an elec-
tronic switch [8206] connected on one end to an input
electromagnetic signal [8204] and on the other end to a
storage capacitor [8208] . . . [and] a load device [8212].” Id.
In the 2011 Action, a jury returned a verdict “rejecting
Qualcomm’s invalidity claims and finding that Qualcomm
directly and indirectly infringed” multiple claims across
four asserted patents. Id. at 1012. Following the verdict,
Qualcomm filed motions for JMOL or alternatively a new
trial on infringement and invalidity issues. The district
court granted Qualcomm’s motion for JMOL of non-
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PARKERVISION, INC. v. QUALCOMM INCORPORATED 4
infringement but denied the motions relating to invalidity.
Both ParkerVision and Qualcomm appealed.
On appeal, we treated claim 23 of the ’551 patent as
representative of all claims asserted in the 2011 Action.
See id. (parties agreeing that differences among other as-
serted claims did “not materially affect the issues on ap-
peal”). Claim 23 of the ’551 patent recites:
An apparatus for down-converting a carrier
signal to a lower frequency signal, compris-
ing:
an energy transfer signal generator;
a switch module controlled by said energy
transfer signal generator; and
a storage module coupled to said switch mod-
ule;
wherein said storage module receives non-neg-
ligible amounts of energy transferred from a
carrier signal at an aliasing rate that is sub-
stantially equal to a frequency of the carrier
signal plus or minus a frequency of the lower
frequency signal, divided by n where n repre-
sents a harmonic or sub-harmonic of the car-
rier signal, wherein a lower frequency signal
is generated from the transferred energy.
’551 patent at 116:24-36 (emphasis added).
The last limitation of claim 23, “wherein said storage
module receives non-negligible amounts of energy trans-
ferred from a carrier signal . . . wherein a lower frequency
signal is generated from the transferred energy,” is re-
ferred to as the “generating limitation.” This “generating
limitation” was the focus of the disputed issues in Par-
kerVision I and is again in this latest appeal as well.
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PARKERVISION, INC. v. QUALCOMM INCORPORATED 5
In ParkerVision I, 621 F. App’x at 1017, we affirmed
the district court’s grant of JMOL of non-infringement. In
doing so, we found that the generating limitation of the
claims asserted in the 2011 Action required that “the ac-
cused products produce a low-frequency baseband signal
using energy that has been transferred . . . into a storage
medium, such as a capacitor or set of capacitors.” Id. at
1013. In other words, in order to infringe representative
claim 23 of the ’551 patent, the down-converting had to oc-
cur at a point in the circuit located at or after the capacitor.
Based primarily on the trial testimony of ParkerVision’s
expert, who opined that in Qualcomm’s accused products
the down-converted baseband signal “already exists before
the capacitor,” we found that “Qualcomm products ob-
tained the [down-converted] baseband signal from ‘some-
where other than’ the energy stored in the capacitors,
precluding a finding of infringement.” Id. at 1014 (empha-
sis added). We subsequently denied ParkerVision’s peti-
tion for rehearing. See ParkerVision, Inc. v. Qualcomm
Inc., 627 F. App’x 921 (Fed. Cir. 2015).
In 2014, while Qualcomm’s motions for JMOL or alter-
natively a new trial were pending in the 2011 Action, Par-
kerVision filed another action against Qualcomm in the
Middle District of Florida (the “2014 Action”), asserting
several patents that had not been at issue in the 2011 Ac-
tion, including (as relevant to this appeal) U.S. Patent Nos.
7,218,907 (“’907 patent”) and 6,091,940 (“’940 patent”).
The ’907 patent is in the same family as the ’551 patent
and teaches technology relating to down-conversion. The
’940 patent is unrelated to the ’551 patent and describes
down-conversion as well as technology relating to “up-con-
verting” of electromagnetic signals. “Up-converting” refers
to converting a low-frequency or baseband electromagnetic
signal into a high-frequency electromagnetic signal. While
down-conversion typically occurs after a wireless device re-
ceives a transmitted signal, up-conversion typically occurs
before a wireless device transmits signals.
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PARKERVISION, INC. v. QUALCOMM INCORPORATED 6
In the 2014 Action, ParkerVision asserted certain
claims primarily directed to down-conversion, referred to
by the parties as “receiver claims,” and others primarily di-
rected to up-conversion, referred to as the “transmitter
claims.”1 The receiver claims, according to the district
court, include claims 1 and 10 of the ’907 patent and claims
24 and 331 of the ’940 patent. Illustrative of the receiver
claims are claim 1 of the ’907 patent and claim 24 of the
’940 patent. Claim 1 of the ’907 patent recites:
A method for down-converting an electromag-
netic signal, comprising:
periodically coupling an electromagnetic sig-
nal that includes a carrier signal to an energy
storage device and a load, wherein the peri-
odic couplings occur at a rate less than twice
the frequency of the carrier signal;
providing, during the periodic couplings, en-
ergy from the electromagnetic signal to the
energy storage device, thereby changing an
amount of energy stored by the energy storage
device;
providing, during the periodic couplings, en-
ergy from the electromagnetic signal to the
load; and
providing, between the periodic couplings, en-
ergy from the energy storage device to the
load, thereby changing the amount of energy
stored by the energy storage device;
1 The “transmitter claims,” according to the district
court, include claims 22 and 25 of the ’940 patent and two
claims of a patent that is not relevant to the issues raised
in this appeal.
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PARKERVISION, INC. v. QUALCOMM INCORPORATED 7
whereby the energy provided to the load forms
a down-converted signal.
’907 patent at 130:64-131:14.
Claim 24 of the ’940 patent depends from independent
claim 22, which itself is a transmitter claim. Claim 22 re-
cites:
An apparatus for communicating comprising:
(a) a transmitting subsystem comprising:
(1) a switch module having a first input
connected to a bias signal, a control in-
put connected to a control signal, and
an output generating a periodic signal,
wherein said control signal is an oscil-
lating signal, said control signal caus-
ing said switch module to gate said bias
signal, said periodic signal having an
amplitude that is a function of said bias
signal, and said periodic signal being a
harmonically rich signal comprised of a
plurality of harmonics, and
(2) a filter to accept said harmonically
rich signal and to output one or more
desired harmonics from said plurality
of harmonics; and
(b) a receiving subsystem.
’940 patent at 69:33-47. Claim 24 recites:
The apparatus of claim 22, wherein said re-
ceiving subsystem comprises:
an aliasing module, further comprising:
(1) a universal frequency translation (UFT)
module, said UFT module aliasing an electro-
magnetic signal according to an aliasing
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PARKERVISION, INC. v. QUALCOMM INCORPORATED 8
signal having an aliasing rate to down-con-
vert said electromagnetic signal, and trans-
ferring energy from said electromagnetic
signal at said aliasing rate;
(2) a signal generator generating said alias-
ing signal, said aliasing signal comprising a
plurality of pulses having non-negligible ap-
ertures; and
(3) a storage device storing energy from said
UFT module.
Id. at 69:54-67.
Neither of the illustrative receiver claims (claim 1 of
the ’907 patent and claim 24 of the ’940 patent) contains an
explicit requirement that the down-converted signal be
generated from energy transferred to an energy storage de-
vice. That is, the receiver claims asserted in the 2014 Ac-
tion do not appear, on their face, to require the “generating
limitation” that turned out to be fatal to ParkerVision’s in-
fringement case in the 2011 Action.
During the pendency of the 2011 and 2014 Actions,
Qualcomm filed several petitions for inter partes review
(“IPR”) of ParkerVision’s ’940 patent. Meanwhile, Par-
kerVision sued Qualcomm at the U.S. International Trade
Commission (“ITC”). The parties jointly requested that the
district court stay the 2014 Action pending resolution of the
IPRs and the ITC proceedings, which the district court
agreed to do.
In one of the IPRs, Qualcomm challenged the patenta-
bility of apparatus and method claims relating to up-con-
version, including claim 25 of the ’940 patent. This same
claim was asserted as one of the transmitter claims in the
2014 Action. The apparatus and method claims that were
considered in the IPRs share certain limitations, including
the requirement of generating or creating “a periodic signal
having a plurality of harmonics.” Id. at 69:27-28
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PARKERVISION, INC. v. QUALCOMM INCORPORATED 9
(apparatus claim 21), 70:5-6 (method claim 25). We will
refer to this as the “harmonically rich signal” limitation.
In its final written decision, the Patent Trial and Ap-
peal Board (“Board”) determined that the challenged appa-
ratus claims of the ’940 patent are unpatentable as obvious
because the prior art taught an apparatus that was “capa-
ble of” performing functions that would satisfy the limita-
tions of the apparatus claims. J.A. 38997. The Board,
however, determined that Qualcomm failed to prove the
challenged method claims would have been obvious, be-
cause Qualcomm’s petition did not address whether a per-
son of ordinary skill in the art would have been motivated
to operate the prior art apparatus in a manner that would
satisfy the limitations of the method claims. On appeal, we
affirmed the Board’s patentability determinations. See
ParkerVision, Inc. v. Qualcomm Inc., 903 F.3d 1354, 1362-
63 (Fed. Cir. 2018) (“ParkerVision II”).
Thereafter, in December 2018, the district court lifted
its stay in the 2014 Action and instructed the parties to
“address whether any patents and claims brought in the
instant litigation are affected by ParkerVision I.” J.A.
5989. Qualcomm responded with a motion for partial sum-
mary judgment of non-infringement of the receiver claims
of the ’907 patent, based on collateral estoppel arising from
ParkerVision I (the “First Motion”). In this First Motion,
Qualcomm contended that the receiver claims of the ’907
patent included “the same concept” as the “generating lim-
itation” of the claims asserted in the 2011 Action, so Par-
kerVision could no longer argue that Qualcomm infringed
these claims. J.A. 9624.
The district court denied Qualcomm’s First Motion,
finding that Qualcomm failed to “show there is no material
difference between the patents-at-issue in ParkerVision I
and the claims now asserted by ParkerVision” in the 2014
Action. J.A. 10344. Specifically, the district court deter-
mined there was expert support in the record for
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PARKERVISION, INC. v. QUALCOMM INCORPORATED 10
ParkerVision’s position that, unlike the 2011 Action claims
containing the generating limitation – which required en-
ergy stored in the capacitors to be used to create the down-
converted baseband signal – the receiver claims of the ’907
patent may only “require[] ‘a down-converted signal’
formed in a load using energy taken directly from the elec-
tromagnetic signal, without charging and discharging a ca-
pacitor.” J.A. 10343. Thus, in connection with the First
Motion, the district court contrasted the generating limita-
tion of the 2011 Action asserted claims, which required
that the down-converting occur at or after the capacitor,
with the receiver claims at issue in the 2014 Action, which
the court recognized might lack the generating limitation
and, therefore, would not exclude down-converting occur-
ring before the capacitor.
As trial approached in the 2014 Action, Qualcomm filed
Daubert motions seeking, as relevant to this appeal, (1) ex-
clusion of the testimony of ParkerVision’s validity expert,
on the grounds that collateral estoppel arising from our af-
firmance in ParkerVision II of the ’940 patent IPR pre-
cludes ParkerVision from attempting to contradict any of
the Board’s findings, and (2) exclusion of testimony from
ParkerVision’s infringement experts based on its unrelia-
bility, due to the experts’ failure to conduct allegedly nec-
essary testing and simulations. Qualcomm also moved
again for summary judgment of non-infringement (the
“Second Motion”), contending, as relevant here, that (1)
ParkerVision is collaterally estopped from asserting Qual-
comm infringes the receiver claims of the ’907 and ’940 pa-
tents, and (2) the accused products do not infringe the
transmitter claims because they do not meet the “harmon-
ically rich signal” limitation.
The district court granted Qualcomm’s Daubert mo-
tions, finding that ParkerVision II, affirming the PTAB’s
invalidation of the challenged apparatus claims ’940 pa-
tent, collaterally estopped ParkerVision from relitigating
characteristics of the prior art reference on which
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PARKERVISION, INC. v. QUALCOMM INCORPORATED 11
Qualcomm’s invalidity contentions rested. The district
court also excluded certain infringement expert testimony,
including testimony relating to infringement of the trans-
mitter claims of the ’940 patent, based on its view that the
experts’ opinions were unreliable.
The district court then granted Qualcomm’s Second
Motion. The court concluded that Qualcomm’s accused
products would not infringe the receiver claims of the ’907
and ’940 patents because “there is no material dispute over
whether the claims at issue here are materially similar to
those in ParkerVision I,” in which we had affirmed the
judgment of non-infringement. J.A. 8. With respect to the
transmitter claims of the ’940 patent, the district court de-
termined that because it had excluded the testimony of
ParkerVision’s infringement experts, Qualcomm’s expert’s
non-infringement opinion was unrebutted. Therefore, the
district court granted summary judgment of non-infringe-
ment of the transmitter claims as well.
ParkerVision timely appealed. After briefing was com-
pleted and oral argument was heard on November 6, 2023,
we determined sua sponte that we lacked jurisdiction over
the appeal because Qualcomm’s counterclaims for invalid-
ity remained unadjudicated and, consequently, there was
no final judgment. See No. 2022-1755 ECF No. 59 at 2. On
July 16, 2024, we dismissed the appeal for lack of jurisdic-
tion, subject to reinstatement, with the reinstated appeal
to be decided by the same panel based on the briefs already
filed and the oral argument heard. See id.
On August 1, 2024, the district court entered a new
judgment, which incorporated its prior order granting
Qualcomm’s summary judgment of non-infringement and
its prior judgment in favor of Qualcomm and against Par-
kerVision, and also expressly dismissed without prejudice
Qualcomm’s counterclaims for invalidity and any remain-
ing claims and counterclaims in the case. See ParkerVi-
sion, Inc. v. Qualcomm Inc., No. 6:14-cv-687-PGB-LHP,
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PARKERVISION, INC. v. QUALCOMM INCORPORATED 12
ECF No. 699 (M.D. Fla. Aug. 1, 2024). On August 5, 2024,
ParkerVision appealed from the August 1 final judgment.
We reinstated ParkerVision’s initial appeal (No. 2022-
1755) and consolidated it with the new appeal (No. 2024-
2221). We have jurisdiction under 28 U.S.C. § 1295(a)(1).
II
We review the district court’s grant of summary judg-
ment according to the law of the applicable regional circuit.
See Lanard Toys Ltd. v. Dolgencorp LLC, 958 F.3d 1337,
1341 (Fed. Cir. 2020). The Eleventh Circuit reviews a
grant of summary judgment de novo, “construing the facts
and drawing all reasonable inferences in favor of the non-
moving party.” Brucker v. City of Doraville, 38 F.4th 876,
881 (11th Cir. 2022) (internal quotation marks omitted).
Summary judgment is appropriate when “there is no genu-
ine dispute as to any material fact and the movant is enti-
tled to judgment as a matter of law.” Fed. R. Civ. P. 56(a);
see also Huggins v. Lueder, Larkin & Hunter, LLC, 39
F.4th 1342, 1345 (11th Cir. 2022). “A genuine dispute of
material fact exists when ‘the evidence is such that a rea-
sonable jury could return a verdict for the nonmoving
party.’” Fernandez v. Trees, Inc., 961 F.3d 1148, 1152 (11th
Cir. 2020) (quoting Anderson v. Liberty Lobby, Inc., 477
U.S. 242, 248 (1986)).
We also apply regional circuit law when reviewing a
district court’s evidentiary rulings. See Omega Pats., LLC
v. CalAmp Corp., 13 F.4th 1361, 1368 (Fed. Cir. 2021). The
Eleventh Circuit “review[s] a district court’s evidentiary
rulings for abuse of discretion.” Great Lakes Ins. SE v.
Wave Cruiser LLC, 36 F.4th 1346, 1353 (11th Cir. 2022). A
district court abuses its discretion “where its decision rests
upon a clearly erroneous finding of fact, an errant conclu-
sion of law, or an improper application of law to fact.” Fur-
cron v. Mail Ctrs. Plus, LLC, 843 F.3d 1295, 1304 (11th Cir.
2016) (internal quotation marks omitted).
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PARKERVISION, INC. v. QUALCOMM INCORPORATED 13
III
ParkerVision raises three issues on appeal. First, Par-
kerVision contends that the district court erred in granting
summary judgment of non-infringement based on the pur-
ported collateral estoppel effect of ParkerVision I. Second,
ParkerVision argues that the district court erred in apply-
ing collateral estoppel to prevent its validity expert from
offering testimony that would have been arguably incon-
sistent with the Board’s findings during the IPR that re-
sulted in invalidation of the apparatus claims of the ’940
patent. Finally, ParkerVision asserts that the district
court abused its discretion in excluding its infringement ex-
perts’ testimony as unreliable. On all three issues, we
agree with ParkerVision.
A
We begin with the district court’s grant of Qualcomm’s
Second Motion, which resulted in entry of summary judg-
ment of non-infringement of the receiver claims of the ’907
and ’940 patents, based on application of collateral estoppel
arising from our ParkerVision I decision.2
Determining whether collateral estoppel, also known
as issue preclusion, applies presents a procedural question
we evaluate according to regional circuit law. See Soverain
Software LLC v. Victoria’s Secret Direct Brand Mgmt.,
LLC, 778 F.3d 1311, 1314 (Fed. Cir. 2015); see also
Uniloc
USA, Inc. v. Motorola Mobility LLC, 52 F.4th 1340, 1346
n.3 (Fed. Cir. 2022). The Eleventh Circuit applies
2 The district court’s grant of the Second Motion also
resulted in summary judgment of non-infringement of the
transmitter claims of the ’940 patent. We address this as-
pect of the Second Motion in connection with our ruling on
the exclusion of ParkerVision’s infringement expert testi-
mony. See infra Part III.C.
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PARKERVISION, INC. v. QUALCOMM INCORPORATED 14
collateral estoppel where the following four elements are
satisfied:
(1) the issue at stake must be identical to the
one involved in the prior litigation; (2) the is-
sue must have been actually litigated in the
prior suit; (3) the determination of the issue
in the prior litigation must have been a criti-
cal and necessary part of the judgment in that
action; and (4) the party against whom the
earlier decision is asserted must have had a
full and fair opportunity to litigate the issue
in the earlier proceeding.
CSX Transp., Inc. v. Bhd. of Maint. of Way Emps., 327 F.3d
1309, 1317 (11th Cir. 2003).3 We apply our own law to
questions involving substantive issues of patent law, in-
cluding any aspects of collateral estoppel that may have
special or unique application to patent cases. See Ohio Wil-
low Wood Co. v. Alps S., LLC, 735 F.3d 1333, 1342 (Fed.
Cir. 2013). Thus, for instance, “the question whether a par-
ticular claim in a patent case is the same as or separate
from another claim has special application to patent cases,
and we therefore apply our own law to that issue.” Aspex
Eyewear, Inc. v. Marchon Eyewear, Inc., 672 F.3d 1335,
1341 n.1 (Fed. Cir. 2012). Whether collateral estoppel ap-
plies is a question of law we review de novo. See Miccosukee
3 The outcome would be the same under Federal Cir-
cuit law, which requires essentially the same four elements
for collateral estoppel. See Empresa Cubana Del Tabaco v.
Gen. Cigar Co., 753 F.3d 1270, 1276 (Fed. Cir. 2014) (“Issue
preclusion requires four preconditions to erect a bar to re-
litigation: (1) identity of the issues in a prior proceeding;
(2) actual litigation of those issues; (3) necessity of the prior
determination to the resulting judgment; and (4) full and
fair opportunities to litigate issues for the party defending
against preclusion.”).
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PARKERVISION, INC. v. QUALCOMM INCORPORATED 15
Tribe of Indians of Fla. v. U.S. Army Corps of Eng’rs, 619
F.3d 1289, 1296 (11th Cir. 2010); see also Aspex Eyewear,
Inc. v. Zenni Optical Inc., 713 F.3d 1377, 1380 (Fed. Cir.
2013).
Here, the parties agree that all but the first of the four
requirements for collateral estoppel are satisfied. They
agree that (1) the issue of whether the accused Qualcomm
products infringe the claims asserted in the 2011 Action
was actually litigated, (2) the determination of that issue
was a critical and necessary part of the judgment in that
action, and (3) ParkerVision had a full and fair opportunity
to litigate the infringement issue in that earlier proceed-
ing. The sole dispute concerns whether the infringement
issue in this case (the 2014 Action) is identical to the in-
fringement issue litigated in the 2011 Action.
The parties have stipulated that the accused products
at issue here operate, in all material respects, in the same
manner as the products accused of infringement in the
2011 Action. Therefore, determining whether the infringe-
ment issue here is the same as the infringement issue in
the 2011 Action requires only an assessment of whether
the receiver claims of the ’907 and ’940 patents asserted in
this case are materially the same as the claims that were
the basis for the finding of non-infringement in the 2011
Action. Evaluating this issue requires a comparison of the
scope of the claims at issue in the 2011 Action with the
scope of the claims asserted here. See Ohio Willow, 735
F.3d at 1342 (explaining collateral estoppel applies when
“the differences between the unadjudicated patent claims
and adjudicated patent claims do not materially alter the
question” at issue). The determination of claim scope, in
turn, is “a matter of claim construction.” Ottah v. Fiat
Chrysler, 884 F.3d 1135, 1139 (Fed. Cir. 2018) (internal
quotation marks omitted).
Consistent with this legal framework, the district court
correctly identified the dispositive issue as being “whether
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PARKERVISION, INC. v. QUALCOMM INCORPORATED 16
the claims [in this 2014 Action] are materially different
from those in ParkerVision I.” J.A. 7 n.5. To resolve this
issue, however, the district court did not undertake claim
construction; nor did it analyze the claim language or con-
sult any other intrinsic evidence to determine the scope of
the claims asserted in this action. Instead, the district
court relied on Qualcomm’s expert reports, which it found
to be “unrebutted,” J.A. 8, and from this extrinsic evidence
concluded that “the [r]eceiver [c]laims at issue here have
the same requirements as the claims in ParkerVision I, in-
cluding the ‘generating limitation.’” J.A. 7 (citing, e.g., J.A.
49082-103, 50497-500). The district court’s analysis suf-
fers from several errors.
First, the district court erred by failing to assess claim
scope by conducting claim construction according to the
process we set out in Phillips v. AWH Corp., 415 F.3d 1303
(Fed. Cir. 2005) (en banc). Instead, as we just noted, the
district court relied principally on extrinsic evidence, par-
ticularly Qualcomm’s expert opinion. The proper approach
to determining claim scope is to “look first to the intrinsic
evidence of record, i.e., the patent itself, including the
claims, the specification and, if in evidence, the prosecution
history.” Vitronics Corp. v. Conceptronic, Inc., 90 F.3d
1576, 1582 (Fed. Cir. 1996). Extrinsic evidence, including
expert and inventor testimony, dictionaries, and treatises,
is “less significant than the intrinsic record in determining
the legally operative meaning of claim language.” Phillips,
415 F.3d at 1317 (internal quotation marks omitted). Ad-
ditionally, and importantly, “[e]xtrinsic evidence may not
be used to contradict claim meaning that is unambiguous
in light of the intrinsic evidence.” Profectus Tech. LLC v.
Huawei Techs. Co., 823 F.3d 1375, 1380 (Fed. Cir. 2016)
(internal quotation marks omitted). Hence, the district
court erred by ignoring the relevant intrinsic evidence and
turning directly to the extrinsic evidence in determining
that the receiver claims asserted in this case have
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PARKERVISION, INC. v. QUALCOMM INCORPORATED 17
materially the same scope as the claims that were at issue
in ParkerVision I.4
Second, the district court erred by treating Qualcomm’s
expert opinion as “unrebutted,” and concluding as a conse-
quence there is “no material dispute over whether the
claims at issue here are materially similar to those in Par-
kerVision I.” J.A. 8. While ParkerVision’s expert was not
as explicit about his opinion as Qualcomm’s expert – Par-
kerVision’s expert did not provide claim charts comparing
the limitations of the 2011 Action claims to the 2014 Action
receiver claims and did not precisely state that the gener-
ating limitation is omitted from the receiver claims as-
serted here – it is evident and indisputable that he
repeatedly opined that there are material differences in the
scope of the claims involved in the two cases that would
materially alter the question of infringement. In particu-
lar, ParkerVision’s expert opined that Qualcomm’s accused
products infringe the asserted receiver claims of the ’907
and ’940 patents because the “down converted signal exists
at the output of the mixer,” which is a point before the ca-
pacitor. J.A. 40334. Because the claims in ParkerVision I,
containing the generating limitation, could only be in-
fringed if the down-conversion occurred at a point at or
4 We are not persuaded by Qualcomm’s suggestion
that ParkerVision “invited” the district court’s error of as-
sessing claim scope without conducting claim construction
and largely without considering the intrinsic evidence. Ap-
pellees’ Br. at 42. Qualcomm, as the party invoking collat-
eral estoppel and the party moving for summary judgment,
bears the burden of proving the identity of the issues liti-
gated in the 2011 and 2014 Actions. See In re McWhorter,
887 F.2d 1564, 1566 (11th Cir. 1989). Thus, if any party
was obligated to request claim construction, it was Qual-
comm, which sought to read into the receiver claims a lim-
itation that is not expressly recited in the claims.
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PARKERVISION, INC. v. QUALCOMM INCORPORATED 18
after the capacitor, see ParkerVision I, 621 F. App’x at
1013-16, the expert’s infringement opinion was necessarily
predicated on his understanding that the claims asserted
here do not contain the generating limitation. More specif-
ically, ParkerVision’s first expert, Dr. Allen, submitted a
declaration (more on that below) opining that claim 1 of the
’907 patent “describes the energy that is provided to the
load (during periodic couplings) from the electromagnetic
signal, without passing through the energy storage device,”
adding that “energy provided to the load, including the en-
ergy provided directly from the electromagnetic signal,
forms a down-converted signal.” J.A. 10091 (emphasis
added). This opinion is plainly in conflict with the gener-
ating limitation’s requirement that down-conversion occur
“using energy that has been transferred . . . into a storage
medium.” ParkerVision I, 621 F. App’x at 1013.
The district court’s abbreviated claim scope analysis in
connection with the Second Motion was inconsistent with
the approach it properly took in denying Qualcomm’s First
Motion. At that earlier point in the litigation, the district
court found “a material issue of fact precluding summary
judgment” based on the declaration filed by ParkerVision’s
expert, Dr. Allen. J.A. 10344. The district court made no
subsequent determination that the Allen declaration on
which it had relied in denying the First Motion was no
longer a part of the record when it considered the Second
Motion. It appears that neither party asked the district
court to strike the Allen declaration, nor to consider or ig-
nore it.5 Moreover, as we have already pointed out, the
5 After the court denied the First Motion, Dr. Allen
withdrew from the case, due to health reasons, and was re-
placed by Dr. Steer, who adopted Dr. Allen’s expert reports
in their entirety. The record appears to contain an ambi-
guity as to whether Dr. Steer also adopted the Allen
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PARKERVISION, INC. v. QUALCOMM INCORPORATED 19
district court did not ever expressly construe the receiver
claims asserted here to include the generating limitation.
Therefore, the record contained the same genuine dispute
of material fact that had compelled the denial of the First
motion. Thus, the trial court erred by treating Qualcomm’s
expert testimony as “unrebutted” and concluding there was
“no material dispute over whether the claims at issue here
are materially similar to those in ParkerVision I.” J.A. 8.
The trial court’s error is further demonstrated by com-
paring our conclusions in ParkerVision I with the question
presented in the Second Motion. In ParkerVision I, 621 F.
App’x at 1013, we concluded that the generating limitation
in each of the claims asserted in the 2011 Action “requires
that the accused products produce a low-frequency [i.e.,
down-converted] baseband signal using energy that has
been transferred from a high-frequency carrier signal into
a storage medium, such as a capacitor or set of capacitors.”
This meant that the down-conversion of the signal had to
occur at or after the capacitor. Our affirmance of the judg-
ment of non-infringement of claim 23 of the ’551 patent was
based on the undisputed fact that Qualcomm’s accused
products do not practice the generating limitation, as they
down-convert the baseband signal before the capacitor. See
id. (ParkerVision expert testifying in 2011 Action that
down-converted baseband signal in accused products “has
already been created before the signal reaches the identified
capacitors”) (emphasis added).
declaration – and whether doing so was necessary, as it ap-
pears ParkerVision reasonably understood the collateral
estoppel issue to have been conclusively resolved in its fa-
vor at the time it substituted Dr. Steer for Dr. Allen. We
leave it for the district court on remand to determine
whether the Allen declaration is or should be part of the
pertinent record (and, if requested, whether to permit ex-
pansion of the record).
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PARKERVISION, INC. v. QUALCOMM INCORPORATED 20
The case now before us involves the same accused prod-
ucts but different claims and, potentially, a materially dif-
ferent infringement question. None of the asserted
receiver claims of the ’907 or ’940 patents expressly in-
cludes the generating limitation or appears to otherwise in-
clude a requirement that the down-converted signal be
generated from the energy transferred to an energy storage
device, such as a capacitor. That is, none of the asserted
receiver claims in this case appears to require that the
down-conversion occur at or after the capacitor; instead,
the claims involved here appear to permit the down-con-
version to occur before the capacitor. In fact, ParkerVi-
sion’s infringement contentions allege, with expert
support, that the capacitor may not even be involved in the
down-conversion.6 Absent a claim construction finding a
generating limitation or similar requirement to be part of
the claims, the Qualcomm accused products might infringe
the receiver claims in this action even if they are found to
down-convert the signal before the capacitor. Thus, we
agree with ParkerVision that there is at least a dispute as
to the scope of the asserted receiver claims of the ’907 and
’940 patents.
Consequently, summary judgment of non-infringement
based on collateral estoppel is not warranted at this stage.
Instead, we vacate the grant of summary judgment and re-
mand for the district court to determine the scope of the
6 Dr. Allen opined in his expert report, which was
adopted by Dr. Steer, that Qualcomm’s accused products
infringe the relevant limitations of, for example, claim 1 of
the ’907 patent because, during periodic couplings, “a
down-converted signal exists at the output of the mixer,”
J.A. 40334, a point before the capacitor, meaning that the
capacitor may not be involved in the down-conversion.
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PARKERVISION, INC. v. QUALCOMM INCORPORATED 21
asserted receiver claims and further to determine whether
that scope is materially different from that of the claims at
issue in the 2011 Action.
In defending the grant of summary judgment of collat-
eral estoppel, Qualcomm relies heavily on ParkerVision’s
experts in this case, who testified in deposition that the re-
ceiver claims of the ’907 and ’940 patents “require that you
produce a lower-frequency signal using energy that’s been
transferred from a higher-frequency signal into a storage
medium.” J.A. 42088. We agree that this testimony might
be understood as an admission that the claims asserted in
this case include a generating limitation or similar require-
ment. However, this is not the sum total of opinions Par-
kerVision’s experts provide; they also both opined, as
already noted, that the receiver claims at issue here do not
require that the down-conversion occur at or after the ca-
pacitor. See, e.g., J.A. 10091, 40334. When the totality of
the record evidence is taken in the light most favorable to
ParkerVision, as the nonmovant, there is sufficient evi-
dence from which a reasonable juror could choose to credit
ParkerVision’s experts’ infringement opinions rather than
view the deposition statements as admissions of non-in-
fringement. See generally Insituform Techs., Inc. v. CAT
Contracting, Inc., 385 F.3d 1360, 1377 (Fed. Cir. 2004) (va-
cating summary judgment because totality of testimony,
including “inconsistent testimony” of witness, “created a
disputed issue of material fact”); see also ACLU of Fla., Inc.
v. Dixie Cnty., 690 F.3d 1244, 1249 (11th Cir. 2012) (“If an
affidavit differs from the statements made in a deposition,
the two in conjunction may disclose an issue of credibility.
Under such circumstances, a district court is not free to
credit one piece of evidence and ignore the other.”) (internal
citation and quotation marks omitted).
Qualcomm next faults ParkerVision for asserting a po-
sition that creates further factual disputes. For example,
with respect to claim 1 of the ’907 patent, Qualcomm ar-
gues that if a down-converted signal already exists with the
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PARKERVISION, INC. v. QUALCOMM INCORPORATED 22
energy that flows directly to the load, then the energy pro-
vided to the load would not “form” a down-converted signal,
as required by claim 1 of the ’907 patent. See ’907 patent
at 131:13-14 (“whereby the energy provided to the load
forms a down-converted signal”). ParkerVision counters
that the term “forms,” which it argues connotes “shapes,”
has a different meaning than “generates” or “creates.” Ap-
pellant’s Reply Br. at 10. With respect to claim 24 of the
’940 patent, Qualcomm contends that if the electromag-
netic signal is down-converted by the UFT module (a type
of switch), then other claim limitations, including “a stor-
age device,” would serve no purpose. ParkerVision re-
sponds that the UFT module down-converts a signal while
the storage device stores energy from the UFT module. Re-
gardless of the merits of the parties’ competing positions on
these (and other) points, the existence of potentially mate-
rial fact disputes only makes all the more clear the need for
additional proceedings on remand.
As a final effort to persuade us that summary judgment
was appropriate, Qualcomm points to instances on which
ParkerVision has relied on similarities between the re-
ceiver claims at issue here and the claims adjudicated in
ParkerVision I. Qualcomm shows that ParkerVision relied
on the same figures to explain the receiver claims in the
2014 Action that it used to explain the claims in the 2011
Action, and also notes that ParkerVision moved to sever
and stay the receiver claims in this case during the pen-
dency of the appeal from the 2011 Action, based on similar-
ities between the two sets of claims. These generalized
acknowledgments of some overlap between the claims do
not, however, constitute admissions that the patent claims
themselves are materially the same in the two actions.
In sum, the district court erred by concluding, without
expressly assessing through the ordinary claim construc-
tion process, that the scope of the claims asserted here is
materially the same as the scope of those at issue in Par-
kerVision I. While claim construction is ultimately a
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PARKERVISION, INC. v. QUALCOMM INCORPORATED 23
question of law, see Teva Pharms. USA, Inc. v. Sandoz, Inc.,
574 U.S 318, 320 (2015) (“The ultimate construction of the
claim is a legal conclusion that the appellate court can re-
view de novo.”), in this appeal we are not well-positioned to
undertake claim construction in the first instance. The
parties have not provided us with claim construction brief-
ing. Moreover, extrinsic evidence, including the testimony
of the parties’ competing experts, may need to be consid-
ered. Subsidiary fact-finding in connection with claim con-
struction is for the trial court to perform, subject to
appellate review for clear error. See id. at 333. Thus, on
remand, the district court should undertake any necessary
claim construction and then determine whether the re-
ceiver claims asserted in this case have the same require-
ment as the generating limitation of the claims at issue in
ParkerVision I. This will allow the district court to then
assess whether there is a difference in claim scope that
would materially alter the question of infringement of the
receiver claims and, accordingly, whether summary judg-
ment based on collateral estoppel is warranted.
B
ParkerVision next contends that the district court
erred in precluding its expert from offering testimony to
support the validity of the ’940 patent method claims
against Qualcomm’s invalidity challenge. As we explained
above, in the IPRs the Board found the ’940 patent’s appa-
ratus claims invalid as obvious while at the same time re-
jecting the effort to prove that patent’s method claims
unpatentable. We affirmed both dispositions in ParkerVi-
sion II. In ruling on Qualcomm’s Daubert motions, the dis-
trict court agreed with Qualcomm that the collateral
estoppel effect of having lost a substantial part of the IPRs
meant ParkerVision was precluded from asking the district
court (or a jury) – as part of its effort to withstand Qual-
comm’s challenge to the validity of the ’940 patent’s method
claims, which survived Qualcomm’s IPR – to reach differ-
ent conclusions than the Board had with respect to up-
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PARKERVISION, INC. v. QUALCOMM INCORPORATED 24
conversion technology and the prior art. The matter in
question concerns the Board’s factual findings concerning
prior art. We disagree with the trial court and, hence, re-
verse the order excluding ParkerVision’s validity expert.
As an initial matter, we reject Qualcomm’s contention
that we lack jurisdiction and cannot consider this aspect of
ParkerVision’s appeal. Qualcomm argues that the only fi-
nal decision we are reviewing is the district court’s judg-
ment of non-infringement. Although Qualcomm presented
a defense of invalidity, the district court did not make a
final determination as to validity; it only made preliminary
determinations as to what evidence could be presented to
the jury if the case had gone forward on the issue of valid-
ity. Our jurisdiction to review district court judgments is
generally limited to appeals from “a final decision of a dis-
trict court.” 28 U.S.C. § 1295(a)(1); see also Halo Elecs.,
Inc. v. Pulse Elecs., Inc., 857 F.3d 1347, 1350 (Fed. Cir.
2017). Our decision to vacate summary judgment of non-
infringement, however, means there will be further pro-
ceedings on remand with respect to the asserted claims of
the ’940 patent, and those proceedings are likely to include
Qualcomm’s invalidity defense. If so, it is in the interest of
judicial economy that we let the district court know now
that it was wrong to exclude ParkerVision’s validity ex-
pert’s opinion, rather than allow the district court to re-
solve invalidity on an improperly truncated record, which
could easily lead to yet another remand. Under such cir-
cumstances, we have discretion to review an issue we be-
lieve will be important on remand. See, e.g., Aspex
Eyewear, 672 F.3d at 1346-47 (vacating summary judg-
ment of non-infringement on res judicata grounds and re-
viewing claim construction rulings in interest of judicial
economy); Interval Licensing LLC v. AOL, Inc., 766 F.3d
1364, 1376 (Fed. Cir. 2014) (reviewing non-dispositive
claim construction that might become important on re-
mand); Advanced Software Design Corp. v. Fiserv, Inc., 641
F.3d 1368, 1378 (Fed. Cir. 2011) (same).
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PARKERVISION, INC. v. QUALCOMM INCORPORATED 25
The application of collateral estoppel is “subject to cer-
tain well-known exceptions.” B & B Hardware, Inc. v. Har-
gis Indus., Inc., 575 U.S. 138, 148 (2015). One is where “the
second action involves application of a different legal
standard, even though the factual setting of both suits may
be the same.” Id. at 154; see also Grogan v. Garner, 498
U.S. 279, 284-85 (1991) (explaining that prior judgment
proven by preponderance of evidence “could not be given
collateral estoppel effect” in subsequent proceeding gov-
erned by clear-and-convincing standard). Although we
have not previously addressed the question of whether a
finding underlying an unpatentability decision in an IPR
proceeding collaterally estops a patentee from making va-
lidity arguments regarding separate, related claims in dis-
trict court litigation, we now hold that it does not.
In the IPR proceedings, Qualcomm’s burden of proof
was only a preponderance of the evidence. See Google LLC
v. IPA Techs. Inc., 34 F.4th 1081, 1085 (Fed. Cir. 2022) (“In
an IPR, the burden of persuasion is on the petitioner to
prove unpatentability by a preponderance of the evi-
dence.”) (internal quotation marks omitted); see also 35
U.S.C. § 316(e). Accordingly, Qualcomm proved the capa-
bilities of the prior art apparatus by a preponderance of the
evidence. To prevail on its invalidity contentions in the
district court, however, Qualcomm must meet a higher bur-
den: clear and convincing evidence. See Microsoft Corp. v.
i4i Ltd. P’ship, 564 U.S. 91, 102 (2011) (“[A] defendant rais-
ing an invalidity defense bore a heavy burden of persua-
sion, requiring proof of the defense by clear and convincing
evidence.”) (internal quotation marks omitted). Qualcomm
has not faced, let alone overcome, this burden previously.
Thus, no finding of the Board (or our affirmance of the
Board in ParkerVision II) estops ParkerVision from pre-
senting evidence on the unresolved question of whether
Qualcomm is able to prove the capabilities of the prior art
apparatus (and the other components of its invalidity con-
tention) by clear and convincing evidence. ParkerVision
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PARKERVISION, INC. v. QUALCOMM INCORPORATED 26
should be provided an opportunity to defend the validity of
its method claims, which were not shown to be unpatenta-
ble in the IPR, with evidence as to what the prior art con-
sidered by the Board does and does not disclose.
Our decision in XY, LLC v. Trans Ova Genetics, 890
F.3d 1282 (Fed. Cir. 2018), involved a different situation.
In XY, we stated that “an affirmance of an invalidity find-
ing, whether from a district court or the Board, has a col-
lateral estoppel effect on all pending or co-pending actions.”
Id. at 1294 (emphasis added); see also Packet Intell. LLC v.
NetScout Sys., Inc., 100 F.4th 1378, 1381 (Fed. Cir. 2024);
Fresenius USA, Inc. v. Baxter Int’l, Inc., 721 F.3d 1330,
1344 (Fed. Cir. 2013). Once we have affirmed the invalidity
of a patent claim – regardless of whether the case leading
to that conclusion arose at the Board, applying a prepon-
derance standard, or in the district court, applying the
more stringent clear and convincing standard – the claim
no longer exists and cannot be asserted as a basis for in-
fringement and “the affirmance of an invalidity finding,
whether from a district court or the Board, has a collateral
estoppel effect on all pending or co-pending actions.” XY,
890 F.3d at 1294. Where, as here, however, we are dealing
with claims that have not been found unpatentable – which
is true of the asserted method claims of the ’940 patent –
those claims remain presumptively valid and can only be
found invalid in district court litigation by clear and con-
vincing evidence.
Because the district court’s application of collateral es-
toppel is legal error, the district court abused its discretion
in excluding the testimony of ParkerVision’s validity ex-
pert. Thus, we reverse the trial court’s grant of Qual-
comm’s Daubert motion.
C
Finally, we turn to ParkerVision’s contention that the
district court erred in excluding the testimony of its in-
fringement experts regarding how Qualcomm’s accused
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PARKERVISION, INC. v. QUALCOMM INCORPORATED 27
products satisfy several disputed limitations of the ’940
transmitter claims, including “harmonically rich signal,”
“gating module,” “switch module,” and “non-negligible en-
ergy.” The district court granted Qualcomm’s Daubert mo-
tion excluding this evidence after finding the opinions at
issue are “unreliable because [they] are not supported by
testing and simulation” of the accused products. J.A. 32.
To be admissible, “proposed expert testimony must be
supported by appropriate validation – i.e., good grounds,
based on what is known.” United States v. Doak, 47 F.4th
1340, 1358 (11th Cir. 2022) (internal quotation marks
omitted). Under Federal Rule of Evidence 703, an expert
can have “good grounds” for his opinion even when he did
not “obtain[] the basis for his opinion from personal percep-
tion.” Monsanto Co. v. David, 516 F.3d 1009, 1015 (Fed.
Cir. 2008). Instead, “experts can base their opinion on facts
or data in the case ‘that the expert has been made aware
of.’” St. Louis Condo. Ass’n, Inc. v. Rockhill Ins. Co., 5 F.4th
1235, 1245 n.8 (11th Cir. 2021) (quoting Federal Rule of
Evidence 703). Moreover, “[a]s a general rule,” in the Elev-
enth Circuit “questions relating to the bases and sources of
an expert’s opinion affect the weight to be assigned that
opinion rather than its admissibility and should be left for
the jury’s consideration.” Carrizosa v. Chiquita Brands
Int’l, Inc., 47 F.4th 1278, 1323 (11th Cir. 2022).
Here, it is undisputed that the materials considered by
ParkerVision’s experts included schematics and technical
documents, which, as Qualcomm conceded, are the “type of
documents . . . that experts in the field would reasonably
consider in evaluating the operation of a circuit.” J.A.
61095. Relatedly, we have observed that “reliance on sci-
entific test results prepared by others may constitute the
type of evidence that is reasonably relied upon by experts.”
Monsanto, 516 F.3d at 1015. There is, then, neither a fac-
tual nor legal basis here for finding that expert testimony
is unreliable unless the expert herself undertakes to test or
simulate the accused products. Indeed, even Qualcomm’s
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PARKERVISION, INC. v. QUALCOMM INCORPORATED 28
senior director of engineering agreed that, in this case, one
could “come to an accurate understanding as to how one of
the accused products works without the need to do an in-
dependent simulation,” as long as one looked “solely at the
simulation results that are contained in the design re-
views.” J.A. 5058. ParkerVision’s experts did precisely
what this Qualcomm witness testified would be sufficient.
See, e.g., J.A. 51073-85.
The district court’s finding that testing and simula-
tions were critical for the experts’ testimony to be reliable
appears to have been based on scientific literature to the
effect that “‘simulation is necessary to accurately predict
detailed circuit behavior.’” J.A. 35 (quoting J.A. 40107).
The district court also seemed to think that ParkerVision
had admitted that tests and simulations were absolutely
necessary. See J.A. 34 (quoting ParkerVision’s argument
that “it’s really not possible to test the actual performance
of a circuit in one of these computer chips without simula-
tion”). The district court committed clear error in reading
the literature’s general statements, and ParkerVision’s
lawyers’ arguments for discovery from Qualcomm, as es-
tablishing a prerequisite for a reliable infringement opin-
ion in the specific context of this case. While Qualcomm’s
attacks on ParkerVision’s experts may well persuade a jury
not to credit the experts’ infringement opinions, the district
court should have left it to jurors to “evaluate the correct-
ness of facts underlying an expert’s testimony.” i4i Ltd.
P’ship v. Microsoft Corp., 598 F.3d 831, 856 (Fed. Cir.
2010); see also Liquid Dynamics Corp. v. Vaughan Co., 449
F.3d 1209, 1221 (Fed. Cir. 2006) (finding expert’s use of “in-
correct data” and “wrong equations” in analysis “goes to the
weight of the evidence rather than the admissibility of [the
expert’s] testimony and analysis”).
Thus, we conclude that the district court abused its dis-
cretion by excluding the testimony of ParkerVision’s in-
fringement experts. We reverse the grant of Qualcomm’s
Daubert motions. We likewise vacate the district court’s
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PARKERVISION, INC. v. QUALCOMM INCORPORATED 29
grant of summary judgment of non-infringement of the
transmitter claims of the ’940 patent, which was based on
the exclusion of ParkerVision’s infringement experts.
IV
We have considered the remaining arguments made by
Qualcomm and find them unpersuasive. For the foregoing
reasons, we vacate the district court’s entry of summary
judgment of non-infringement, reverse its grant of the
Daubert motions relating to ParkerVision’s validity and in-
fringement experts, and remand for further proceedings
consistent with this opinion.
VACATED-IN-PART, REVERSED-IN-PART, AND
REMANDED
COSTS
Costs awarded to appellant.
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