Court Opinion

ID: 3066253
Source: CourtListenerOpinion
Date Created: 2015-10-14 23:52:43.100615+00
Date Added: 2024-06-11T11:41:27.703377
License: Public Domain

NOTE: This disposition is nonprecedential.

  United States Court of Appeals
      for the Federal Circuit
                 ______________________

         PARKERVISION, INC., A FLORIDA
               CORPORATION,
               Plaintiff-Appellant

                            v.

   QUALCOMM INCORPORATED, A DELAWARE
              CORPORATION,
          Defendant-Cross-Appellant
           ______________________

                  2014-1612, 2014-1655
                 ______________________

   Appeals from the United States District Court for the
Middle District of Florida in No. 3:11-cv-00719-RBD-JRK,
Judge Roy B. Dalton, Jr.
                 ______________________

                 Decided: July 31, 2015
                 ______________________

   DONALD ROBERT DUNNER, Finnegan, Henderson,
Farabow, Garrett & Dunner, LLP, Washington, DC,
argued for plaintiff-appellant. Also represented by ERIK R.
PUKNYS, Palo Alto, CA; JOSHUA WRIGHT BUDWIN, KEVIN
LEE BURGESS, McKool Smith, PC, Austin, TX; DOUGLAS
AARON CAWLEY, Dallas, TX.

   TIMOTHY TETER, Cooley LLP, Palo Alto, CA, argued
for defendant-cross-appellant. Also represented by
2            PARKERVISION, INC.   v. QUALCOMM INCORPORATED

BENJAMIN G. DAMSTEDT, JEFFREY S. KARR, LORI R. MASON,
STEPHEN C. NEAL; JEFFREY A. LAMKEN, MARTIN TOTARO,
MoloLamken LLP, Washington, DC; JOHN M. WHEALAN,
Chevy Chase, MD.
               ______________________

     Before LOURIE, BRYSON, and CHEN, Circuit Judges.
BRYSON, Circuit Judge.
    In this patent infringement action, ParkerVision, Inc.,
alleged that Qualcomm Inc. infringed ParkerVision’s
patented technology relating to “down-converting” elec-
tromagnetic signals. At issue are U.S. Patent Nos.
6,061,551 (“the ’551 patent”), 6,266,518 (“the ’518 pa-
tent”), 6,370,371 (“the ’371 patent”), and 7,496,342 (“the
’342 patent”), all owned by ParkerVision.
    “Down-converting” refers to converting a modulated
high-frequency electromagnetic signal into a low-
frequency or “baseband” signal in an electronic device
such as a wireless receiver. ParkerVision claims methods,
systems, and apparatuses for down-converting a high-
frequency signal using a technique called “energy sam-
pling.” That technique differs from the technique of
“voltage sampling,” which was used in conventional down-
converting systems.
    ParkerVision’s energy sampling system uses the same
circuit configuration as a voltage sampling system. At the
most basic level, the energy sampling system consists of
an electronic switch connected on one end to an input
electromagnetic signal and on the other end to a storage
capacitor followed by a load device or resistor. See, e.g.,
’551 patent, Figs. 82A, 82B. ParkerVision designed its
down-converting system to perform energy sampling,
rather than voltage sampling, by increasing the size of the
capacitor, increasing the duration of the period that the
switch is closed, and decreasing the impedance value of
the load.
PARKERVISION, INC.   v. QUALCOMM INCORPORATED            3

    Claim 23 of the ’551 patent is representative of the
asserted claims. It recites:
      23. An apparatus for down-converting a carrier
      signal to a lower frequency signal, comprising:
      an energy transfer signal generator;
      a switch module controlled by said energy trans-
      fer signal generator; and
      a storage module coupled to said switch module;
      wherein said storage module receives non-
      negligible 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 carrier
      signal, wherein a lower frequency signal is gen-
      erated from the transferred energy.
Other asserted claims use slightly different language.
The parties agree that the differences in the claim lan-
guage do not materially affect the issues on appeal.
    ParkerVision developed energy sampling in 1996 and
1997, and it applied for its first patent relating to that
technology in October 1998. Before any patent issued,
ParkerVision approached Qualcomm to license its inven-
tion. No agreement was reached, however.
    In 2011 ParkerVision filed this action against Qual-
comm, alleging that Qualcomm had been infringing its
energy-sampling patents since 2006. The district court
bifurcated the trial. The first phase dealt with validity
and infringement, and the second phase dealt with dam-
ages and willfulness. At the conclusion of the validity and
infringement phase, the jury returned a verdict rejecting
Qualcomm’s invalidity claims and finding that Qualcomm
directly and indirectly infringed claims 23, 25, 161, 193,
4             PARKERVISION, INC.   v. QUALCOMM INCORPORATED

and 202 of the ’551 patent; claims 27, 82, 90, and 91 of the
’518 patent; claim 2 of the ’371 patent; and claim 18 of the
’342 patent. At the conclusion of the damages and will-
fulness phase, the jury awarded ParkerVision $172.7
million in damages but found that Qualcomm’s infringe-
ment was not willful.
    Following the trial, Qualcomm filed motions for judg-
ment as a matter of law (“JMOL”) and for a new trial on
both invalidity and infringement. The court granted
Qualcomm’s motion for JMOL of non-infringement but
denied Qualcomm’s motions relating to invalidity. This
appeal and cross-appeal followed.
                              I
     At trial, ParkerVision accused 19 Qualcomm products
of infringing the asserted claims. 1 To prove infringement,
ParkerVision called Paul Prucnal, its technical expert,
and David Sorrells, one of the inventors. Dr. Prucnal’s
testimony focused on Qualcomm’s Magellan product, but
he stated that his opinion regarding the Magellan product
applied to each of Qualcomm’s accused products. 2 Mr.
Sorrells testified with regard to only one of the 19 accused
products, the Solo product.
    The district court based its non-infringement ruling
on two grounds. First, the court found that the accused
products did not practice the limitation that recites “gen-

    1  The verdict form erroneously listed 20 Qualcomm
products, including the “Marimba” product. The jury
found that all 20 products infringed, even though Par-
kerVision had presented no evidence regarding the Ma-
rimba product at trial.

    2   Qualcomm did not present an infringement expert
of its own at trial, but called a fact witness to testify as to
the design of certain accused products.
PARKERVISION, INC.   v. QUALCOMM INCORPORATED            5

erating a lower frequency signal,” which is present in each
asserted claim. The court held that ParkerVision’s in-
fringement expert conceded that in the accused products
the baseband signal was created before, or “upstream
from,” the storage capacitor. That concession, the court
concluded, was fatal to ParkerVision’s claim under the
“generating” limitation. Second, the court concluded that
Qualcomm’s “50% duty cycle” products did not practice
the “sampling” limitation, which is found in claims 27, 82,
90, and 91 of the ’518 patent, and in claim 2 of the ’371
patent. 3   We agree with the district court on both
grounds.
                             A
    The generating limitation in each of the asserted
claims requires that the accused products produce a low-
frequency 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.
    Dr. Prucnal testified that the accused products satisfy
the generating limitation by using a specific type of
circuitry called a “double-balanced mixer” combined with
a pair of capacitors connected to the output ports of the
mixer. It is undisputed that double-balanced mixers
existed prior to ParkerVision’s invention and that a
double-balanced mixer by itself (i.e., without the addition
of output capacitors) can be used to convert high-
frequency carrier signals into low-frequency baseband
signals. ParkerVision argues that Qualcomm implements
the double-balanced mixer in an infringing configuration
because it uses storage capacitors to interact with the

   3    Claims 90 and 91 of the ’518 patent and claim 2 of
the ’371 patent use the term “sub-sampling” or “sub-
sample,” which the court construed to mean “sampling at
an aliasing rate.”
6            PARKERVISION, INC.   v. QUALCOMM INCORPORATED

mixer in producing the baseband signal. According to Dr.
Prucnal, the mixer and the capacitors in Qualcomm’s
circuit collectively function to convert the high-frequency
carrier signal into the low-frequency baseband signal. In
doing so, Dr. Prucnal testified, the mixer-capacitor combi-
nation satisfies the generating limitation.
    Qualcomm contends that the mixer alone converts the
carrier signal into the baseband signal and that the
capacitors identified by ParkerVision do not generate the
baseband signal. According to Qualcomm, those capaci-
tors are used to filter out unwanted high-frequency sig-
nals known as “jammers.” Because the capacitors are not
involved in the down-converting function, the baseband
signal necessarily comes from “somewhere other than . . .
energy that has been stored in the capacitor.” For that
reason, Qualcomm contends, its products do not infringe.
    The parties’ dispute thus centers on whether the ca-
pacitors immediately downstream from the mixer are
involved in generating the baseband signal. In order for
ParkerVision to prevail under its infringement theory, it
was required to show that the baseband signal is generat-
ed from the energy stored in those capacitors.
    Dr. Prucnal testified that the identified capacitors in
the accused products contribute to the generation of the
baseband signal by going through a “charging and dis-
charging” cycle, which is controlled by a switch inside the
mixer circuit. Closing the switch allows energy from the
carrier signal to flow into the capacitor and accumulate
there (“charging”); opening the switch allows the capacitor
to release the accumulated energy into the rest of the
circuit (“discharging”). Dr. Prucnal testified that the
charging and discharging cycle results in an accumulation
of energy from the carrier signal, which is then used “to
generate the baseband signal following the capacitor.”
    On cross-examination, however, Dr. Prucnal admitted
that the baseband signal in the accused products has
PARKERVISION, INC.   v. QUALCOMM INCORPORATED              7

already been created before the signal reaches the identi-
fied capacitors. He also testified that the “output” of the
double-balanced mixer “is the baseband,” and that the
double-balanced mixer “in fact” creates the baseband
signal. 4
    Dr. Prucnal’s testimony is internally inconsistent. He
testified that energy accumulated in the storage capacitor
is used to generate a baseband signal “following the
capacitor” but admitted that the baseband already exists
before the capacitor. He also testified that the switch
inside the mixer circuit works together with the storage
capacitors to generate the baseband signal, while agree-
ing that the mixer itself creates the baseband.
    ParkerVision made no attempt to reconcile the two
strands of Dr. Prucnal’s testimony at trial. The only other
testimony that the jury heard regarding the respective
role of the mixer and the storage capacitors in the accused

    4    The parties disagree about the location of the iden-
tified capacitors. Qualcomm asserts that the capacitors
are located within a circuit module known as the “TX
filter,” which immediately follows the mixer module in the
accused products. ParkerVision admits that some capaci-
tors are located inside the TX filter but contends that
other capacitors are located within the mixer module
itself, and that the two groups of capacitors are both
involved in generating the baseband signal. We need not
resolve the dispute as to the location of the identified
capacitors. Regardless of whether some capacitors should
be considered to be within the mixer module, Dr. Prucnal
acknowledged that the double-balanced mixer shown in
Qualcomm’s design, consisting of crisscrossed transistor
pairs, generates the baseband signal and that the output
of that circuit structure, which precedes both sets of
capacitors identified by ParkerVision, “is the baseband.”
8            PARKERVISION, INC.   v. QUALCOMM INCORPORATED

products came from Qualcomm’s witness, Jim Jaffee, an
engineer who was responsible for designing the Magellan
product. 5 Mr. Jaffee testified—consistent with Dr. Pruc-
nal’s admission on cross-examination—that the baseband
signal is created in the crisscrossed transistors of the
double-balanced mixer. He added that the capacitors
immediately following the mixer “play no role” in generat-
ing the baseband and are designed to “have no effect” on
the baseband; instead, the capacitors serve only to sup-
press the unwanted “transmit jamming” signal.
    The inconsistencies in Dr. Prucnal’s testimony con-
cern matters that are at the heart of the parties’ dispute.
Mr. Sorrells conceded that Qualcomm would not infringe
if the Qualcomm products obtain the baseband signal
“somewhere other than from the . . . energy that has been
stored in the capacitor.” He acknowledged that to meet
its burden to prove infringement, ParkerVision had to
prove that “the current that has gone into the storage
capacitor is then what is generating the baseband signal”
in the accused products.
    Dr. Prucnal’s admission that the double-balanced
mixer creates the baseband signal before that signal
reaches the identified capacitors means that Qualcomm
products obtained the baseband signal from “somewhere
other than” the energy stored in the capacitors, preclud-
ing a finding of infringement. Because ParkerVision
provided no explanation at trial for the inconsistencies in
Dr. Prucnal’s testimony, no reasonable jury could be

    5  Mr. Sorrells did not discuss how the mixer or the
storage capacitors function in Qualcomm’s products in
connection with the “generating” limitation.
PARKERVISION, INC.   v. QUALCOMM INCORPORATED              9

satisfied that Dr. Prucnal’s opinion, taken as a whole,
provides a substantial basis for a finding of infringement. 6
    During the hearing on Qualcomm’s post-trial JMOL
motion, ParkerVision attempted to reconcile Dr. Prucnal’s
admission that the baseband signal exists at the output of
the mixer and before the storage capacitors with his
testimony that energy stored in the capacitors is used to
generate the baseband signal following the capacitors.
ParkerVision argued that what comes out of the mixer is
merely a “lower frequency signal” (compared to the carrier
signal), but was not the baseband. According to Par-
kerVision, the lower frequency signal goes into the capaci-
tors, where it is stored as energy, and that energy is then
used to generate the baseband signal—a different signal
than the “lower frequency signal”—following the capaci-
tors.
    No evidence supports such a theory, however. Dr.
Prucnal affirmatively identified the output of the double
balanced mixer as “the baseband.” He did so during both
cross and redirect examination. Neither Dr. Prucnal nor
any other witness alluded to the possibility that the signal
that comes out of the mixer is different from the base-
band. Thus, the record does not support ParkerVision’s
theory at the JMOL hearing that the output of the mixer
is something other than the baseband signal; its effort to

    6  On appeal, ParkerVision relies heavily on a state-
ment made by Dr. Prucnal during cross-examination that
“the actual baseband signal on the baseband path is
created after the capacitor resistor.” That statement does
not support ParkerVision’s infringement argument,
however, because the statement referred to Dr. Prucnal’s
simulation (which did not contain a double balanced
mixer), not to Qualcomm’s accused circuit. Dr. Prucnal
admitted that what was shown in his simulation “was not
the actual output of the Qualcomm circuit.”
10           PARKERVISION, INC.   v. QUALCOMM INCORPORATED

reconcile the inconsistencies in Dr. Prucnal’s testimony
fails.
    ParkerVision alludes to the “two baseband signals”
theory in its brief, but disclaims reliance on it. See App.
Br. 55, Reply Br. 20. Instead, ParkerVision argues on
appeal that the district court misunderstood the underly-
ing technology when it distinguished between a signal
appearing upstream from the capacitor and a signal
appearing downstream from the capacitor on the same
electric wire. According to ParkerVision, it “makes no
sense” to pinpoint a specific location along a wire where
the baseband signal is generated, because all the points
along the wire “are one and the same point.”
    ParkerVision did not present its “one and the same
point” theory to the jury or explain the relevance of that
theory to its infringement claim. The only evidence
ParkerVision now relies on to support that theory is the
testimony of Dr. Razavi, Qualcomm’s invalidity expert,
who testified that, in one of the prior art references the
wire “right above the capacitor . . . is the same point.”
    Dr. Razavi’s testimony, however, does not support
ParkerVision’s theory. In the prior art reference that Dr.
Razavi was discussing, the baseband signal is represented
by voltage across the capacitor. As Dr. Razavi testified,
voltage is the same at all points along an electric wire. It
is undisputed, however, that the accused products are not
“voltage-mode” products, but are “current-mode” products,
in which the baseband signal is represented by variations
in current, not by variations in voltage.
     At trial, Dr. Prucnal agreed that within the TX filter
in Qualcomm’s design, a larger current flows before the
capacitor while a smaller current flows after the capaci-
tor, which indicates that part of the incoming current has
PARKERVISION, INC.   v. QUALCOMM INCORPORATED
                                                         11

been “filtered out” by the capacitor. 7 Dr. Prucnal further
explained that the relationship between the currents
flowing before and after the capacitor (along the same
wire) and the current going into the capacitor are gov-
erned by what is known as Kirchhoff’s current law.
    Dr. Prucnal’s testimony demonstrates that, unlike a
voltage signal, which is the same everywhere along an
electric wire, currents flowing along the same wire may be
different before and after a capacitor. That difference, in
accordance with Kirchhoff’s current law, is determined by
how much current is absorbed, or filtered out, by the
capacitor. Dr. Razavi’s “one and the same point” testimo-
ny, which was directed to a voltage signal, is thus inappli-
cable to current-mode devices such as Qualcomm’s
accused products.
     The testimony of ParkerVision’s witnesses makes
clear that, in order to generate the baseband signal ac-
cording to ParkerVision’s invention, electric current from
the carrier signal first flows into the storage capacitor and
is accumulated there as energy. When that energy is
discharged to the rest of the circuit, a baseband signal
“following the capacitor” is created. But Dr. Prucnal
admitted that the double-balanced mixer creates the
baseband current in the accused Qualcomm products and
that the electric current upstream from the identified
capacitors in those products is already “the baseband.” In
other words, the accused products do not require an
electric current from the carrier signal to go in and out of
the storage capacitors in order to create the baseband
signal; instead, the baseband current is created by the
double-balanced mixer before the current reaches the

    7  The evidence shows that the TX filter serves to fil-
ter out the high frequency “jamming noise” in the trans-
ceiver system that otherwise would overwhelm the
baseband signal.
12           PARKERVISION, INC.   v. QUALCOMM INCORPORATED

capacitors. The district court therefore did not err in
finding Dr. Prucnal’s admission to be “fatal” to ParkerVi-
sion’s infringement theory.
    ParkerVision argues that simply because the base-
band signal appears upstream from the identified capaci-
tors does not mean the capacitors have no role in generat-
generating the signal, because the patents explain how
capacitors can influence signals that appear elsewhere in
the circuit. That argument misses the point. The ques-
tion is not whether, as a general matter, a capacitor can
affect signals appearing upstream from it; the question is
whether, in Qualcomm’s products, the baseband signal
appearing upstream from the capacitors is affected by the
capacitors in the way ParkerVision says it is. Dr. Prucnal
and Mr. Sorrells testified that current from the carrier
signal must go in and out of the identified capacitors in
order to generate a baseband signal “following the capaci-
tor.” That a baseband current already exists before the
current from the carrier signal reaches the capacitors
shows that the baseband signal is not generated in the
way ParkerVision asserts. We therefore agree with the
district court that no reasonable jury could have found
that the accused products satisfy the “generating” limita-
tion under ParkerVision’s infringement theory.
                            B
    As an additional reason for granting Qualcomm’s mo-
tion for JMOL of non-infringement, the district court also
held that Qualcomm’s “50% duty cycle products” could not
infringe the “sampling” limitation found in certain claims.
The court construed “sampling” to mean “reducing a
continuous-time signal to a discrete-time signal.” That
construction is not disputed on appeal.
     Qualcomm’s accused products can be divided into the
“25% duty cycle products” and the “50% duty cycle prod-
ucts.” According to Dr. Prucnal, “duty cycle is the period
of time during a cycle during which the switch is closed”;
PARKERVISION, INC.   v. QUALCOMM INCORPORATED
                                                       13

having a 50 percent duty cycle means that “the switch is
closed for half of the duty cycle and open for the other
half.”
    At trial, when asked what had led to his belief that
Qualcomm’s products infringed the “sampling” limitation
of ParkerVision’s patents, Mr. Sorrells pointed to the
description in Qualcomm’s design documents of “a 25
percent duty cycle” product. Mr. Sorrells distinguished
his invention from the prior art on the ground that tradi-
tional double-balanced mixers are “50% duty cycle, con-
tinuous input/continuous output devices,” meaning that
“there is always a connection” from the input of those
devices to the output of the devices. He agreed that if
there exists a continuous input and continuous output,
the sampling limitation is not satisfied. Mr. Sorrells
added, however, that Qualcomm uses a 25% duty cycle in
some of its products, which results in a “discrete on and
discrete off time” in those products. In those products, he
testified, there is no continuous connection from the input
to the output that would preclude infringement.
     Dr. Prucnal focused on Qualcomm’s Magellan product,
a 25% duty cycle product. According to Dr. Prucnal, the
Magellan product satisfies the sampling limitation.
Because he testified that his analysis regarding the
Magellan product was applicable to all the other 25% duty
cycle products, the jury could have found from his testi-
mony that all the accused 25% duty cycle products satis-
fied the sampling limitation. With respect to the 50%
duty cycle products, however, Dr. Prucnal’s testimony was
entirely conclusory. Despite acknowledging the existence
of a “50-percent duty cycle issue” relating to the “sam-
pling” limitation, Dr. Prucnal merely stated that the 50%
duty cycle products do not have a duty cycle “that’s al-
ways at 50 percent,” and that their duty cycles could “vary
to less than 50 percent.”
14           PARKERVISION, INC.   v. QUALCOMM INCORPORATED

     The district court found Dr. Prucnal’s testimony re-
garding the 50% duty cycle products to be insufficient to
establish infringement. We agree. Mr. Sorrells’ testimo-
ny highlighted the significance of the distinction between
the 25% and the 50% duty cycles for purposes of deter-
mining whether the sampling limitation is satisfied. That
is, traditional double-balanced mixers using a 50% duty
cycle do not “sample,” because there is a continuous input
and continuous output in those circuits. Certain accused
products, on the other hand, satisfy the sampling limita-
tion because they use a 25% duty cycle that produces
discrete on and off periods.
    Dr. Prucnal’s testimony that the actual duty cycles of
the 50% duty cycle products could vary “to less than 50
percent” falls short of establishing infringement. Dr.
Prucnal failed to explain, for instance, how the less-than-
50% duty cycle helps produce discrete on and off periods,
and how it prevents a continuous input and continuous
output that exists in traditional double-balanced mixers
using a perfect 50% duty cycle. Without any explanatory
testimony or other evidence on that point, Dr. Prucnal’s
conclusory statement regarding the 50% duty cycle prod-
ucts cannot establish that those products infringe the
sampling limitation. 8

     8   On appeal, ParkerVision complains that the dis-
trict court relied on evidence outside the trial record in
determining whether the 50% duty cycle products satisfy
the sampling limitation. While the court noted that Dr.
Prucnal’s trial testimony regarding the 50% duty cycle
products “fell short of that relied on by ParkerVision to
avoid summary judgment,” the court’s ultimate finding of
non-infringement rested on the vague and conclusory
nature of Dr. Prucnal’s testimony, not on any difference
between his testimony and the evidence proffered on
summary judgment.
PARKERVISION, INC.   v. QUALCOMM INCORPORATED
                                                      15

    We affirm the district court’s grant of Qualcomm’s
motion for JMOL of non-infringement as to all asserted
claims. 9
                             II
    In its cross-appeal, Qualcomm argues that all the as-
serted claims are invalid in light of two references, nei-
ther of which was previously considered by the Patent and
Trademark Office. Although the district court acknowl-
edged that Qualcomm’s argument on invalidity was
“compelling,” it denied Qualcomm’s JMOL motion and its
motion for a new trial on the ground that the jury had a
sufficient basis to disbelieve Dr. Razavi, Qualcomm’s
invalidity expert. 10
                             A
    Qualcomm argues that the first reference, an article
by Weisskopf, anticipates all the asserted claims except
claim 18 of the ’342 patent. The Weisskopf reference,
entitled “Subharmonic Sampling of Microwave Signal
Processing Requirements,” explores “the theory behind
subharmonic sampling,” and “the criteria for optimum
sampling hardware performance.” It discloses a circuit
diagram similar to the one disclosed in ParkerVision’s

   9    Qualcomm also argues (1) that JMOL of non-
infringement should be affirmed on the alternative
ground of no induced infringement; and (2) that the
district court should have granted Qualcomm’s JMOL
motion and its motion for a new trial on damages. Be-
cause we affirm the grant of JMOL of non-infringement
on the grounds discussed above, we need not address
Qualcomm’s additional arguments.

   10    ParkerVision did not present an invalidity expert
of its own at trial.
16           PARKERVISION, INC.   v. QUALCOMM INCORPORATED

patents, in that it consists mainly of a switch connected to
a storage capacitor.
    At trial, Dr. Razavi conducted a limitation-by-
limitation comparison of the Weisskopf reference and the
asserted claims. He explained that Weisskopf, like the
ParkerVision patents, discloses transferring a maximum
amount of energy from the carrier signal to the storage
capacitor and then generating a baseband signal using
that transferred energy. Dr. Razavi also conducted cir-
cuit-level simulations based on Weisskopf’s circuit dia-
gram to address the claim limitation that “the transfer-
transferring of energy substantially prevents accurate
voltage reproduction of the carrier signal during the
apertures.” That limitation appears in claim 202 of the
’551 patent and in substance in claim 91 of the ’518 pa-
tent, but not in the other asserted claims.
    ParkerVision argues that the district court correctly
denied Qualcomm’s motion for judgment as a matter of
law of invalidity for three reasons. First, Weisskopf does
not disclose transferring “non-negligible amounts of
energy” from the carrier signal to the storage capacitor.
Second, Weisskopf does not disclose generating a base-
band signal using the transferred energy. Third, the jury
was not required to accept Dr. Razavi’s opinions because
they were based on inaccurate simulations.
                             1
    The asserted claims all require transferring “non-
negligible amounts of energy” from the carrier signal to a
storage device, such as the storage capacitor in Weisskopf.
The district court construed “non-negligible amounts of
energy” to mean “energy in amounts that are distinguish-
able from noise.” That construction is not disputed on
appeal.
    At trial, Dr. Razavi testified that Weisskopf chooses
the values of the various circuit components in order to
PARKERVISION, INC.   v. QUALCOMM INCORPORATED
                                                        17

“maximiz[e] the transfer of energy from the carrier signal
. . . to the capacitor.” ParkerVision replies that Weisskopf
fails to disclose transferring energy from the carrier
signal in amounts distinguishable from noise, and that
Dr. Razavi’s “conclusory” testimony cannot fill that gap in
the prior art reference. We disagree.
    It is true that in describing the amounts of energy
transferred from the carrier signal to the storage capaci-
tor, neither the Weisskopf reference nor Dr. Razavi re-
ferred to “amounts distinguishable from noise” in those
words. We have held, however, that the failure of a
reference to disclose a claim limitation in the same words
used by the patentee is not fatal to a claim of invalidity.
Application of Glasser, 363 F.2d 449, 455 (CCPA 1966);
see also Teva Pharm. Indus. Ltd. v. AstraZeneca Pharm.
LP, 661 F.3d 1378, 1384 (Fed. Cir. 2011) (a prior inventor
need not “conceive of its invention using the same words
as the patentee would later use to claim it.”).
    Mr. Sorrells explained at trial that transferring a non-
negligible amount of energy into the storage capacitor
means “that you have to transfer enough energy to over-
come the noise in the system to be able to meet your
specifications.” He further testified that the fact that the
accused Qualcomm products meet “all of the cellu-
lar/cellphone specifications” is proof that a “non-
negligible” amount of energy is transferred to the storage
element in those products.
    Mr. Sorrells’ testimony thus establishes that to de-
termine whether or not energy in amounts distinguisha-
ble from noise has been transferred from the carrier
signal, one may look to whether the down-converting
circuit functions in practice. If a circuit successfully
down-converts, that is proof that enough energy has been
transferred to overcome the noise in the system.
   The Weisskopf reference discloses such a down-
converting system. Weisskopf touts the ability of the
18           PARKERVISION, INC.   v. QUALCOMM INCORPORATED

disclosed circuit to down-convert a high frequency carrier
signal to a baseband “with great efficiency and without
loss of fidelity.” Dr. Razavi testified, without contradic-
tion, that the Weisskopf system is designed to maximize
the amount of energy transferred from the carrier signal.
The fact that Weisskopf transfers as much energy as
possible from the carrier signal, resulting in a commer-
cially viable down-converting system is proof that the
system successfully distinguishes the transferred energy
from noise. No reasonable jury could have concluded
otherwise.
     ParkerVision faults Dr. Razavi for not adding noise to
his circuit simulation in connection with his testimony
that Weisskopf satisfied the “non-negligible amounts of
energy” limitation. But Dr. Razavi did not rely on simula-
tions with regard to the “non-negligible amounts of ener-
gy” limitation; he used simulations only to prove that the
different claim limitation was met: “prevent[ing] accurate
voltage reproduction of the carrier signal.” The trial
record (and in particular Mr. Sorrells’ testimony) estab-
lished that performing a noise-added computer simulation
is not the only way to ascertain whether “non-negligible
amounts of energy” are transferred. Thus, Dr. Razavi’s
failure to conduct a noise-added simulation does not affect
the probative force of his testimony regarding the “non-
negligible amounts of energy” limitation.
                            2
    ParkerVision next contends that the Weisskopf refer-
ence does not disclose generating a baseband signal using
the transferred energy. It is undisputed that Weisskopf
generates a baseband signal, and that the baseband
signal is generated by measuring the voltage across the
storage capacitor. ParkerVision points out, however, that
Weisskopf advises against using a low-impedance load in
the down-converting circuit on the ground that it “would
cause energy to leak out of the capacitors,” i.e., it would
PARKERVISION, INC.   v. QUALCOMM INCORPORATED
                                                        19

cause the capacitors to discharge. At trial, ParkerVision
distinguished its claims from the Weisskopf reference by
noting that Weisskopf generates the baseband signal
“without discharging energy from the [storage] capacitor.”
ParkerVision’s position on invalidity thus turns on
whether the generating limitation requires that energy be
discharged from the storage capacitors.
    The record shows that it does not. In the initial claim
construction order, the district court adopted the plain
and ordinary meaning of the term “generating.” In its
subsequent order on ParkerVision’s motion for summary
judgment of no invalidity, the court explicitly rejected
ParkerVision’s assertion that the plain and ordinary
meaning of “generating” requires discharging energy from
a storage device. The court found that the “generating”
limitation is not restricted to the generation of a baseband
signal by discharging energy from a storage device, but
encompasses the generation of a baseband signal by other
means as well. ParkerVision does not challenge that
interpretation of the “generating” limitation on appeal.
    Because the generating limitation does not require
that the baseband signal be created by discharging energy
from a storage device, ParkerVision cannot rely on the
absence of that feature from Weisskopf to defeat Qual-
comm’s anticipation claim. See Ecolab, Inc. v. FMC Corp.,
569 F.3d 1335, 1347 (Fed. Cir. 2009) (the argument that
prior art did not anticipate the claim “is unpersuasive
because claim 7 is written broadly and is not limited to
PAA treatment in a meat processing plant.”); Verdegaal
Bros. v. Union Oil Co., 814 F.2d 628, 632 (Fed. Cir. 1987)
(“[T]here is no limitation in the subject claims with re-
spect to the rate at which sulfuric acid is added, and,
therefore, it is inappropriate for Verdegaal to rely on that
distinction [against a claim of anticipation.]”).
    Although the generating limitation does not require
discharging energy from the storage device, claim 27 of
20           PARKERVISION, INC.   v. QUALCOMM INCORPORATED

the ’518 patent, which recites “a method for down-
converting a carrier signal to a baseband signal,” contains
an explicit, additional step of “transferring energy to a
load during off-time.” ’518 patent, claims 1, 27. At trial,
Dr. Razavi testified that the “transferring energy” limita-
tion means that “when the switch is turned off . . . energy
is coming out of the [storage] capacitor going to a load,”
i.e., energy is “leaking away” from the storage capacitor.
Thus, in order for Weisskopf to anticipate this additional
claim limitation, it must be shown that Weisskopf teaches
discharging energy from the storage capacitor.
     Dr. Razavi testified that Weisskopf teaches two sce-
narios in which a baseband signal may be generated. In
one scenario, energy is not discharged from the storage
capacitor, while in the second scenario, energy is dis-
charged. Dr. Razavi admitted, however, that Weisskopf
“doesn’t put [the second scenario] in a positive light.” In
particular, he acknowledged that Weisskopf explicitly
taught that discharging energy from the storage capacitor
(e.g., by using a “low impedance load”) may result in “poor
hold duration,” which “manifests itself as an increasing
inability of the sample-and-hold circuit to isolate the
periodic sampling function . . . from the output of the
sample-and-hold circuit.”
    Based on that evidence, a reasonable jury could con-
clude that Weisskopf does not teach discharging the
storage capacitor as part of “a method for down-
converting a carrier signal to a baseband signal,” which
claim 27 of the ’518 patent requires. That is because
discharging the storage capacitor in Weisskopf’s system
may cause “inability” of the system to successfully pro-
duce a baseband signal at the output. Therefore, a rea-
sonable jury could have discredited Dr. Razavi’s
testimony that Weisskopf teaches “transferring energy to
a load during off-time,” as required by claim 27 of the ’518
patent, and accordingly could have found claim 27 not to
be anticipated by Weisskopf. The district court’s denial of
PARKERVISION, INC.   v. QUALCOMM INCORPORATED
                                                       21

Qualcomm’s motion for JMOL of invalidity is thus proper
as to that claim. And because the jury’s finding that
claim 27 of the ’518 patent was not anticipated was not
against the great weight of the evidence, we uphold the
district court’s determination that a new trial on that
issue is not warranted.
                              3
    ParkerVision further challenges Dr. Razavi’s opinions
regarding the Weisskopf reference on the ground that his
opinions are based on inaccurate simulations. As noted
above, Dr. Razavi relied on the simulations only with
respect to the claim limitation that “accurate voltage
reproduction” of the carrier signal is prevented, which
appears in claim 202 of the ’551 patent and in claim 91 of
the ’518 patent.
    ParkerVision asserts first that the jury was not re-
quired to accept Dr. Razavi’s simulations, because Dr.
Razavi admitted that his simulations did not account for
noise, even though it would have been possible to design a
simulation that would have done so.
    At trial, Dr. Razavi testified that, in order to deter-
mine whether accurate voltage reproduction of the carrier
signal is prevented, he looked to the simulated waveform
of the voltage signal “going into the switch.” A waveform
representing a “distorted” replica of the source signal,
according to Dr. Razavi, is proof that “accurate voltage
reproduction” has been prevented.
    ParkerVision cross-examined Dr. Razavi regarding
the lack of noise in his simulations, asking him to confirm
that the court’s claim construction requires transferring
“energy [in] amounts distinguishable from noise”—a
limitation for which Dr. Razavi did not rely on his simula-
tions. With respect to the “preventing accurate voltage
reproduction” limitation, for which Dr. Razavi did rely on
simulations, ParkerVision asked Dr. Razavi no questions
22           PARKERVISION, INC.   v. QUALCOMM INCORPORATED

relating to noise. Nothing in the trial record connects
noise to the “preventing accurate voltage reproduction”
claim limitation, much less suggests that adding noise to
simulations is necessary to prove that limitation. 11 Be-
cause nothing in the trial record suggests that omitting
noise in the simulations would affect Dr. Razavi’s testi-
mony regarding the “preventing accurate voltage repro-
duction” limitation, no reasonable jury could reject Dr.
Razavi’s simulations on the basis that they did not in-
clude noise.
     ParkerVision’s second complaint regarding Dr. Raza-
vi’s simulations is that Dr. Razavi “omitted certain ele-
ments and picked values that were not actually
disclosed.” In particular, ParkerVision points to Dr.
Razavi’s acknowledgement that in his circuit model he
omitted a resistor that is placed in front of the buffer in
Weisskopf’s circuit diagram. ParkerVision also asserts
that Dr. Razavi “made up” the value of a source resistor in
his circuit model that is not disclosed in Weisskopf.
    Regarding the omitted resistor, Dr. Razavi explained
that the omission is “immaterial” because the “high
impedance buffer [following the resistor] . . . doesn’t draw
any current,” regardless of whether the resistor is includ-
ed in the simulations. Dr. Razavi further testified that he
had not “made up” the value of the source resistor but had
taken that value from the Weisskopf reference.
    ParkerVision’s criticism of Dr. Razavi’s computer
simulations for omitting the identified resistor suffers
from the same flaw as its earlier argument that the
simulation does not account for noise: It fails to tie the

     11When Dr. Prucnal testified as to how the “prevent-
ing accurate reproduction” limitation is met in the ac-
cused products, he relied on the period of time during
which the switch is closed.
PARKERVISION, INC.   v. QUALCOMM INCORPORATED
                                                        23

alleged defect in the simulation to the claim limitation
that Dr. Razavi was addressing at trial, i.e., “prevent[ing]
accurate voltage reproduction of the carrier signal.” Dr.
Razavi testified that, because the buffer immediately
following the resistor in Weisskopf is a “high impedance
buffer,” omission of the resistor from the simulations was
immaterial to the result. ParkerVision failed to offer any
explanation of how the omitted resistor would undermine
the validity of Dr. Razavi’s simulation results. Without
any such explanation, a reasonable jury would have had
no basis to disbelieve Dr. Razavi’s testimony or to reject
his simulations based on the omitted resistor.
    Finally, there is no force to ParkerVision’s contention
that Dr. Razavi “made up” the value of the source resistor
in his simulation. Dr. Razavi used a 50 ohm source
resistor in his simulation; he did so in accordance with
Weisskopf’s explicit disclosure of a 50 ohm “source imped-
ance.” Thus, there is no evidence that any of the alleged
defects with Dr. Razavi’s computer simulations would
undermine the validity of his simulation results.
    We conclude that ParkerVision has failed to point to
any basis on which a reasonable jury could have rejected
Dr. Razavi’s opinions that Weisskopf anticipates claims
23, 25, 161, 193, and 202 of the ’551 patent, claims 82, 90,
and 91 of the ’518 patent, and claim 2 of the ’371 patent.
We reverse the district court’s denial of Qualcomm’s
motion for JMOL of invalidity as to those claims. As
noted above, however, we affirm the district court’s denial
of Qualcomm’s motions for JMOL and for a new trial of
invalidity as to claim 27 of the ’518 patent.
                             B
    At trial, Qualcomm sought to invalidate claim 18 of
the ’342 patent through a second prior art reference—an
excerpt from a book entitled “Practical RF Design Manu-
al” by Doug DeMaw.
24            PARKERVISION, INC.   v. QUALCOMM INCORPORATED

     Claim 18 of the ’342 patent recites a “method for
down-converting an electromagnetic signal” based on a
“differential” configuration of ParkerVision’s energy
sampling system. Figure 16H of the ’342 patent is an
embodiment of the differential energy sampling system
used in claim 18. It consists of a pair of input signals
representing carrier information and “inverted” carrier
information, respectively; a first and a second switch; a
first and a second capacitor connected to the first and
second switch, respectively; and a first and a second
impedance device following the capacitors. See ’342
patent, Fig. 16H; claim 18.
     Qualcomm asserts that the DeMaw reference, and in
particular a circuit diagram disclosed in DeMaw (“Figure
6.7 Dual FET balanced mixer using a Siliconix U430
device”), teaches every element of claim 18 of the ’342
patent. At trial, Dr. Razavi first conducted a component-
by-component comparison between the circuit diagram
described in Figure 16H of the ’342 patent and that
described in Figure 6.7 of DeMaw. He concluded that
DeMaw discloses all the components of Figure 16H.
According to Dr. Razavi, the transistors designated as Q1
and Q2 in DeMaw correspond to the first and second
switches in Figure 16H, and the two signals at the input
of Q1 and Q2 in DeMaw, which represent the carrier
signal and an “inverted” copy of the carrier signal, corre-
spond to the “carrier plus” and “carrier minus” signals
shown in Figure 16H. The pair of capacitors that are
shown immediately next to the outputs of Q1 and Q2
correspond to the first and second capacitors in Figure
16H. And Dr. Razavi identified the two additional capaci-
tors shown to the right of the first pair of capacitors as the
first and second impedance devices, noting that an “im-
pedance can be a capacitor.” ParkerVision does not
challenge that part of Dr. Razavi’s testimony.
PARKERVISION, INC.   v. QUALCOMM INCORPORATED
                                                        25

    Dr. Razavi next explained how DeMaw teaches each
limitation of claim 18. In doing so, he showed the jury the
results of computer simulations that he had performed
according to the circuit diagram disclosed in Figure 6.7 of
DeMaw and explained how the simulation results sup-
ported his conclusions.
     Only one claim limitation is in dispute here: “perform-
ing a plurality of charging and discharging cycles of the
first and second capacitors to generate first and second
down-converted information signals across first and
second impedance devices, respectively.” 12 ParkerVision
contends that DeMaw does not anticipate claim 18 be-
cause it does not expressly teach the claim limitation of
“charging and discharging” capacitors to generate a
baseband signal. Anticipation, however, “can occur when
a claimed limitation is ‘inherent’ or otherwise implicit in
the relevant reference,” even though the reference does
not expressly teach that limitation. Standard Havens
Prods., Inc. v. Gencor Indus., Inc., 953 F.2d 1360, 1369
(Fed. Cir. 1991), citing Tyler Refrigeration v. Kysor Indus.
Corp., 777 F.2d 687, 689 (Fed. Cir. 1985).
    Dr. Razavi testified that “charging and discharging of
the first and second capacitors” occurs when the first and
second switches (Q1 and Q2) “are turned on and off at a
certain rate.” As the capacitors are charged and dis-
charged, he explained, the down-converted information
signal first appears at the outputs of Q1 and Q2, although
at that point the down-converted signal is mixed with
other high frequency signals, such as the local oscillator
signal and the RF, or carrier, signal. He added that the
signals appearing at the outputs of Q1 and Q2 propagate
further down the remainder of the circuit where the high

   12  ParkerVision also cross-examined Dr. Razavi re-
garding “sampling,” but the “sampling” limitation is not
found in claim 18 of the ’342 patent.
26           PARKERVISION, INC.   v. QUALCOMM INCORPORATED

frequency components are removed, resulting in a “clean”
down-converted signal appearing across the first and
second impedance devices located at the far end of the
DeMaw circuit. Dr. Razavi’s computer simulations illus-
trated the waveforms of the “information signal” as that
signal travels through the various components of the
DeMaw circuit, changing from a high-frequency signal at
the input of the switch to a down-converted, low-
frequency signal appearing across the identified imped-
ance device.
    Thus, even though Figure 6.7 of DeMaw does not ex-
pressly state that the capacitors engage in “charging and
discharging” to generate a baseband signal, Dr. Razavi’s
detailed testimony regarding the DeMaw circuit estab-
lished that charging and discharging is “implicit” in that
reference. ParkerVision sought to challenge Dr. Razavi’s
testimony in various respects on cross-examination, but
none of its questioning undermined Dr. Razavi’s explana-
tion of the operation of the DeMaw circuit and how Figure
6.7 of DeMaw corresponds to Figure 16H of the ’342
patent.
    ParkerVision also challenged Dr. Razavi’s computer
simulations at trial, faulting him for assigning values to
certain components of the DeMaw circuit that were not
provided in DeMaw itself. Dr. Razavi admitted that
DeMaw does not disclose the values of certain capacitor
and inductor components; he explained, however, that he
used simulations only to “illustrate one or two effects [of
the DeMaw circuit],” and that the component values he
picked for the simulations did not affect his conclusion
that “DeMaw exactly matches the claim language.”
    Again, ParkerVision asserted that Dr. Razavi’s com-
puter simulations were defective, but it did not provide
any suggestion as to how any alleged defects in the simu-
lations undermined Dr. Razavi’s uncontradicted testimo-
ny. Because there is no basis on which a reasonable jury
PARKERVISION, INC.   v. QUALCOMM INCORPORATED
                                                         27

could reject the evidence that DeMaw anticipates claim 18
of the ’342 patent, we reverse the district court’s denial of
Qualcomm’s motion for JMOL of invalidity regarding
claim 18.
    Costs to Qualcomm.
  AFFIRMED IN PART and REVERSED IN PART