`
`IPR2021-00990
`U.S. Patent No. 7,110,444
`Patent Owner’s Response
`
`
`
`
`
`UNITED STATES PATENT AND TRADEMARK OFFICE
`
`____________________________
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`
`____________________________
`
`TCL Industries Holdings Co., Ltd. and Hisense Co., Ltd.,
`Petitioners
`
`v.
`
`ParkerVision, Inc.
`Patent Owner
`
`U.S. Patent No. 7,110,444
`
`Issue Date: September 19, 2006
`Title: WIRELESS LOCAL AREA NETWORK
`(WLAN) USING UNIVERSAL FREQUENCY
`TRANSLATION TECHNOLOGY INCLUDING
`MULTI-PHASE EMBODIMENTS AND
`CIRCUIT IMPLEMENTATIONS
`__________________________________________________________________
`
`Inter Partes Review No. IPR2021-00990
`
`__________________________________________________________________
`
`PATENT OWNER’S RESPONSE TO PETITION FOR
`INTER PARTES REVIEW OF UNITED STATES PATENT NO. 7,110,444
`
`
`
`

`

`
`
`Table of Contents
`
`Page
`
`I.
`
`INTRODUCTION. .......................................................................................... 1
`
`II.
`
`“STORAGE ELEMENT” HAS BEEN CONSTRUED .................................. 2
`
`III. PETITIONERS SHOULD BE PRECLUDED FROM RAISING NEW
`ARGUMENTS/THEORIES ............................................................................ 3
`
`IV. LEVEL OF ORDINARY SKILL IN THE ART ............................................. 4
`
`V. GENERAL OVERVIEW OF WIRELESS TECHNOLOGY ......................... 4
`
`A. Wired communications. ........................................................................ 4
`
`B. Wireless Communications. .................................................................... 5
`
`C.
`
`Frequency. ............................................................................................. 6
`
`D. Up-conversion. ...................................................................................... 7
`
`E.
`
`Down-conversion. ................................................................................. 8
`
`VI. WIRELESS TECHNOLOGY ......................................................................... 9
`
`A.
`
`Basic circuit concepts. ........................................................................... 9
`
`B.
`
`C.
`
`Circuit diagrams. ................................................................................. 11
`
`Transistors ........................................................................................... 11
`
`D.
`
`Capacitors. ........................................................................................... 12
`
`E.
`
`F.
`
`Resistor. ............................................................................................... 13
`
`Differential amplifier. .......................................................................... 14
`
`G.
`
`Electrical load and impedance. ............................................................ 14
`
`VII. VOLTAGE V. ENERGY SAMPLING ......................................................... 15
`
`A. Voltage sampling. ................................................................................ 15
`
`B.
`
`Energy Sampling. ................................................................................ 16
`
`i
`
`

`

`
`
`C. Key take-aways. .................................................................................. 17
`
`D.
`
`Secondary considerations. ................................................................... 17
`
`VIII. THE ’444 PATENT ....................................................................................... 19
`
`A. Overview ............................................................................................. 19
`
`B.
`
`The patent discloses two fundamentally different down-conversion
`systems. ............................................................................................... 24
`
`1.
`
`2.
`
`Energy transfer (energy sampling). .......................................... 25
`
`Sample-and-hold (voltage sampling). ....................................... 31
`
`C.
`
`Prosecution history. ............................................................................. 35
`
`IX. CLAIM CONSTRUCTION .......................................................................... 36
`
`A.
`
`“Storage element” ................................................................................ 36
`
`B.
`
`C.
`
`“[a] wireless modem apparatus” ......................................................... 38
`
`“Frequency down-conversion module” ............................................... 39
`
`D.
`
`“Subtractor module” ............................................................................ 40
`
`X.
`
`CITED REFERENCES ................................................................................. 41
`
`A. U.S. Patent No. 6,230,000 (“Tayloe”) ................................................ 41
`
`B.
`
`Texas Instruments Datasheet (“TI Datasheet”) ................................... 55
`
`C. U.S. Patent No. 5,937,013 (“Lam”) .................................................... 55
`
`D.
`
`Circuit Techniques for Reducing the Effects of Op-Amp
`Imperfections (“Enz”) ......................................................................... 57
`
`XI. THE CLAIMS ARE PATENTABLE ........................................................... 59
`
`A. GROUND 1: Tayloe in View of the TI Datasheet. ............................. 59
`
`1.
`
`Tayloe Capacitors Hold Negligible Amounts Of Energy. ........ 59
`
`a.
`
`Energy in a Tayloe Capacitor. ........................................61
`
`ii
`
`

`

`
`
`
`
`
`
`STEP 1: Calculating available energy ................................................. 61
`
`b.
`
`c.
`
`STEP 2: Calculating energy in capacitor. .......................64
`
`STEP 3: Percentage of available energy. .......................65
`
`2.
`
`Energy in ParkerVision’s storage element................................ 65
`
`a.
`
`b.
`
`c.
`
`STEP 1: Calculating available energy. ...........................65
`
`STEP 2: Energy stored on storage element. ...................66
`
`STEP 3: Percentage of available energy. .......................67
`
`Tayloe capacitors are not elements of an energy transfer system.
` ................................................................................................... 68
`
`Tayloe does not disclose a “wireless modem apparatus.” ........ 72
`
`TI Datasheet does not cure deficiencies of Tayloe ................... 74
`
`3.
`
`4.
`
`5.
`
`B. GROUND 2: – Lam in View of Enz/Tayloe ....................................... 74
`
`1.
`
`2.
`
`3.
`
`4.
`
`5.
`
`6.
`
`Lam and Enz Capacitors Hold Negligible Amounts Of Energy.
` ................................................................................................... 74
`
`Lam/Enz capacitors are not elements of an energy transfer
`system. ....................................................................................... 76
`
`Enz does not disclose a “frequency down-conversion module to
`down-convert [the/said] input signal.” ...................................... 77
`
`Lam do not disclose a “wireless modem apparatus.” ............... 79
`
`Claim 4 is not obvious in view of Lam/Enz. ............................ 79
`
`There is no motivation to combine Lam and Enz. .................... 80
`
`
`
`iii
`
`

`

`
`
`Cases
`
`Table of Authorities
`
` Page(s)
`
`Apple Inc. v. Andrea Elecs. Corp.,
`949 F.3d 697 (Fed. Cir. 2020) ............................................................................ 36
`
`Baran v. Med. Device Techs., Inc.,
`616 F.3d 1309 (Fed. Cir. 2010) .......................................................................... 36
`
`Pitney Bowes, Inc. v. Hewlett-Packard Co.,
`182 F.3d 1298 (Fed. Cir. 1999) .......................................................................... 38
`
`TEK Global, S.R.L. v. Sealant Sys. Int’l, Inc.,
`920 F.3d 777 (Fed. Cir. 2019) ............................................................................ 40
`
`Williamson v. Citrix Online, LLC,
`792 F.3d 1339 (Fed. Cir. 2015) .................................................................... 39, 40
`
`
`
`
`
`
`
`iv
`
`

`

`
`
`
`
`PATENT OWNER’S EXHIBIT LIST
`
`1003
`1004
`1005
`
`1006
`1007
`
`Exhibit Description
`1001
`U.S. Patent No. 7,110,444 (“the ’444 patent”)
`1002 Declaration of Dr. Matthew B. Shoemake Regarding U.S. Patent No.
`7,110,444
`’444 patent File History
`U.S. Patent No. 6,230,000 (“Tayloe”)
`SN74CBT3253D Dual 1-of-4 FET Multiplexer/Demultiplexer (rev. ed.
`May 1998) (“TI Datasheet”)
`U.S. Patent No. 5,937,013 (“Lam”)
`Circuit Techniques for Reducing the Effects of Op-Amp Imperfections:
`Autozeroing, Correlated Double Sampling, and Chopper Stabilization,
`Proceedings of the IEEE, Vol.84, No.11, November 1996 (“Enz”)
`Haque et al, A Two Chip PCM Voice CODEC With Filters, IEEE
`Journal of Solid-State Circuits, Vol. 4, SC-14, No. 6, Dec. 1979
`(“Haque”)
`U.S. Patent No. 5,764,693 (“Taylor”)
`U.S. Patent No. 5,742,641 (“Dingsor”)
`Final Written Decision, Intel Corp. v. ParkerVision, Inc., IPR2020-
`01265 (Jan. 21, 2022)
`Claim Construction Order, ParkerVision, Inc. v. Intel Corp., No. 6:20-
`cv-00108-ADA (W.D. Tex.)
`Claim Construction Order, ParkerVision, Inc. v. Intel Corp., No. 6:20-
`cv-00562-ADA (W.D. Tex.)
`Amended Claim Construction Order, ParkerVision, Inc. v. Intel Corp.,
`No. 6:20-cv-00562-ADA (W.D. Tex.)
`Special Master’s Recommended Claim Constructions, ParkerVision,
`Inc. v. Hisense Co., Ltd. et al., No. 6:20-cv-00870-ADA (W.D. Tex.)
`Special Master’s Recommended Claim Constructions, ParkerVision,
`Inc. v. TCL Industries Holdings Co., No. 6:20-cv-00945-ADA
`“Transistor,” The American Heritage College Dictionary (3rd ed.
`1997)
`Donald Christiansen, Electronics Engineers’ Handbook (4th ed. 1996)
`Richard C. Jaeger, Microelectronic Circuit Design (1997)
`Rudolf Graf, Modern Dictionary of Electronics (7th ed. 1999)
`J. Crols, “A 1.5 GHz Highly Linear CMOS Downconversion Mixer,
`IEEE J. Solid-State Circuits, Vol. 30, No.7, pp. 736-742, July 1995
`
`1008
`
`1014
`1015
`2016
`
`2017
`
`2018
`
`2019
`
`2020
`
`2021
`
`2022
`
`2023
`2024
`2025
`2026
`
`v
`
`

`

`
`
`2027
`
`2028
`
`2029
`2030
`
`A. Rofougaran, J. Chang, M. Rofougaran, and A. Abidi, “A 1 GHz
`CMOS RF Front-End IC for a Direct-Conversion Wireless Receiver,”
`IEEE J. Solid-State Circuits, Vol. 31, No. 7, pp. 880-889, July 1996
`B. Razavi, “Challenges in Portable RF Transceiver Design,” IEEE
`Circuits and Devices, Vol. 12, No. 5, pp. 12-25, Sept. 1996
`U.S. Patent No. 6,061,551
`B. Razavi, “CMOS RF receiver design for wireless LAN applications,”
`IEEE Radio and Wireless Conference, pp. 275-280, Aug. 1999
`Qualcomm Email dated Aug. 11, 1998
`2031
`Qualcomm Email dated Feb. 2, 1999
`2032
`Qualcomm Email dated Oct. 7, 1998
`2033
`Qualcomm Email dated Feb. 4, 1999
`2034
`Thomas L. Floyd, Principles of Electric Circuits (5th ed. 1997)
`2035
`2036 Martin Hartley Jones, A practical introduction to electronic circuits (3rd
`ed. 1995)
`“General Purpose Single
`SGS-THOMSON Microelectronics,
`Operational Amplifier UA741” (October 1997)
`Declaration of Dr. Michael Steer
`Kevin McClaning, Wireless Receiver Design
`Communications (SciTech Publishing 2012)
`
`2037
`
`2038
`2039
`
`for Digital
`
`
`
`
`
`vi
`
`

`

`
`
`I.
`
`INTRODUCTION.
`
`Though this Board has previously considered claim 3 of U.S. Patent No.
`
`7,110,444 (“the ’444 patent”) in view of Tayloe/TI Datasheet (IPR2020-01265),
`
`ParkerVision now presents arguments that were not previously made or that the
`
`Board excluded as untimely and, thus, did not consider. These arguments distinguish
`
`the cited references from the challenged claims.
`
`This case relates to how wireless modems process radio signals.
`
`At bottom, the dispute is whether the cited references disclose the claimed
`
`“storage element” and “wireless modem.” They do not.
`
`Although the Board and U.S. District Court for the Western District of Texas
`
`(“District Court”) previously construed the term “storage element” differently, both
`
`constructions require that a “storage element” “stores non-negligible amounts of
`
`energy from an input electromagnetic signal.”1
`
`Notably, while the Petition addresses the District Court’s constructions of
`
`other claim terms, the Petition is silent regarding the construction of “storage
`
`element.” TCL/Hisense (“Petitioners”) asserting in a reply that a capacitor in the
`
`prior art “stores non-negligible amounts of energy” would be a new argument/theory
`
`and should be precluded.
`
`
`1 Unless otherwise noted, all emphasis has been added.
`
`
`
`1
`
`

`

`
`
`But, as discussed below, unlike the claimed “storage element,” the capacitors
`
`in the cited references only hold negligible amounts of energy.
`
`Moreover, the cited references disclose voltage sampling systems. The ’444
`
`patent, however, specifically reserved the term “storage element” to refer to an
`
`element of an energy transfer (energy sampling) system – a fundamentally different
`
`and competing technology to voltage sampling. To hold that the cited references
`
`(voltage sampling systems) disclose a “storage element” is inconsistent with the ’444
`
`specification, which states that voltage sampling systems use “holding” elements,
`
`not “storage” elements.
`
`Finally, whereas the challenged claims are directed to a “wireless modem,”
`
`the cited references are not.
`
`For the foregoing reasons, claims 2-4 should be upheld as patentable.
`
`II.
`
` “STORAGE ELEMENT” HAS BEEN CONSTRUED
`
`In January 2022, the Board construed “storage element” as “an element of a
`
`system that stores non-negligible amounts of energy from an input EM signal.” See
`
`Ex.-2016, 41.
`
`In January 2021, the District Court construed “storage element” as “an
`
`element of an energy transfer system that stores non-negligible amounts of energy
`
`from an input electromagnetic signal.” Ex.-2017, 5; see also Ex.-2018, 2; Ex.-2019,
`
`2 (construing “storage module”).
`
`
`
`2
`
`

`

`
`
`In October 2021, the District Court appointed Dr. Joshua Yi2 as a Special
`
`Master to address claim construction in litigations involving Petitioners.3 Dr. Yi
`
`recommended construing “storage element” consistent with the District Court’s
`
`prior constructions. See Ex.-2020, 5; Ex.-2021, 5.
`
`III. PETITIONERS SHOULD BE PRECLUDED FROM RAISING NEW
`ARGUMENTS/THEORIES
`
`The Petition was filed in May 2021 – four months after the District Court’s
`
`Order construing “storage element” and nine days after ParkerVision filed its POR
`
`in IPR2020-01265. Thus, when filing the Petition, Petitioners were aware of the
`
`District Court’s construction and all of ParkerVision’s arguments regarding “storage
`
`element.” Indeed, the Petition even addresses or adopts the District Court’s
`
`constructions of other terms and analyzes the claims in view of those constructions.
`
`Pet., 15, 18, 54-55, 63.
`
`But the Petition is notably silent regarding the District Court’s construction of
`
`“storage element,” which “stores non-negligible amounts of energy” (language that
`
`the Board adopted in IPR2020-01265 and Petitioners incorporated into their
`
`
`2 In ParkerVision/Intel litigations, Dr. Yi, a PhD in electrical engineering, served as
`
`a law clerk/technical advisor.
`
`3 In litigation, Petitioners agreed that the construction of “storage element” and
`
`“storage module” should be consistent. See Exs.-2020, 2021.
`
`
`
`3
`
`

`

`
`
`construction of “storage element” in litigation). Instead, the only argument/theory
`
`Petitioners put forth is simply to identify “storage elements” as capacitors in the cited
`
`references. See Pet., 58-59, 75-76.
`
`Petitioners could have addressed the District Court’s construction of “storage
`
`element,” but chose not to do so. Petitioners addressing this issue in a reply would
`
`be a new argument/theory. Thus, Petitioners should be precluded from doing so.
`
`IV. LEVEL OF ORDINARY SKILL IN THE ART
`
`A POSITA at the time of the invention of the ’444 patent would have: (a) a
`
`Bachelor of Science degree in electrical or computer engineering (or a related
`
`academic field), and at least two (2) additional years of work experience in the design
`
`and development of radio frequency circuits and/or systems, or (b) at least five (5)
`
`years of work experience and training in the design and development of radio
`
`frequency circuits and/or systems. See Ex.-2038 ¶24.
`
`V. GENERAL OVERVIEW OF WIRELESS TECHNOLOGY
`
`A. Wired communications.
`
`Traditional wired communications networks transmit audio signals over wire
`
`lines by converting audio signals to electrical signals and back to audio signals. Ex.-
`
`2038 ¶27.
`
`
`
`4
`
`

`

`
`
`When Bob speaks into a phone, Bob’s phone converts his voice (low
`
`frequency audio signals) into electrical signals. Electrical signals are transmitted
`
`over wires to Alice’s phone, which converts the electrical signals back into audio
`
`
`
`signals so that Alice can hear Bob’s voice. Ex.-2038 ¶28.
`
`B. Wireless Communications.
`
`Similar to wired communications, in wireless communications, low frequency
`
`audio signals are converted into electrical signals. But instead of traveling through
`
`wires, the signals are transmitted through the air as radio waves (electromagnetic
`
`(EM) waves). Ex.-2038 ¶29.
`
`As shown above, wireless devices use high radio frequency (RF) signals (e.g.,
`
`above 300 MHz (red)) because high frequency signals can carry more information
`
`
`
`
`
`5
`
`

`

`
`
`and because high frequency antennas can physically fit within small devices such as
`
`cellular phones. Ex.-2038 ¶30.
`
`
`
`In a wireless communication, when Bob speaks into his cell phone, Bob’s cell
`
`phone converts his voice (low frequency audio signals) into a high frequency RF
`
`signal. The RF signal is transmitted over the air to Alice’s cell phone. Alice’s cell
`
`phone then converts the RF signal back into a low frequency audio signal and Alice
`
`can hear Bob’s voice. Ex.-2038 ¶31.
`
`C.
`
`Frequency.
`
`Frequency is the number of cycles of a wave per unit time (second). Ex.-2038
`
`¶32.
`
`
`
`
`
`6
`
`

`

`
`
`As shown above, a high frequency signal has more cycles of a wave per
`
`second than a low frequency signal. Notably, the frequency of an audio wave can be
`
`one thousand cycles per second whereas the frequency of a radio wave can be one
`
`billion cycles per second. Ex.-2038 ¶33.
`
`D. Up-conversion.
`
`In order to transmit an audio signal over air, a wireless device must transform
`
`the audio signal to an RF signal. Since the RF signal is used to carry the information
`
`in the audio signal, the RF signal is referred to as a “carrier signal.” And since audio
`
`waves are at a low frequency, they are referred to as “baseband,” a “baseband signal”
`
`or at a “baseband frequency.” Ex.-2038 ¶34.
`
`
`
`In order to transport the baseband (audio) signal, the transmitting wireless
`
`device (e.g., Bob’s cell phone) modifies the carrier (RF) signal. As shown above, the
`
`baseband signal is impressed upon the carrier signal (above left), thereby
`
`modulating/changing the shape of the carrier signal to approximate the shape of the
`
`
`
`7
`
`

`

`
`
`baseband (audio) signal (above right).4 The modified signal is referred to as a
`
`“modulated carrier signal.” The process is referred to as “up-conversion” because
`
`the low frequency signal is being up-converted to a high frequency signal. Ex.-2038
`
`¶35.
`
`E. Down-conversion.
`
`In order for the receiving wireless device (e.g., Alice’s cell phone) to recover
`
`the baseband (audio) signal from the modulated carrier signal, the receiving wireless
`
`device must transform the modulated carrier signal back to an audio signal. This
`
`process includes “down-conversion” because a high frequency signal is being down-
`
`converted to a low frequency signal. Ex.-2038 ¶36.
`
`As shown above, “down-conversion” is the process by which the baseband
`
`(audio) signal is recovered from the carrier signal. Down-conversion is the subject
`
`of the challenged claims of the ’444 patent.5 Ex.-2038 ¶37.
`
`
`
`
`4 This type of modification is referred to as amplitude modulation. But other types
`
`of modulation can be used. Ex.-2038 ¶35. n.1.
`
`5 Discussion of voice/audio signals is for illustrative purposes only.
`
`
`
`8
`
`

`

`
`
`VI. WIRELESS TECHNOLOGY
`
`A. Basic circuit concepts.
`
`RF signals are created using electronic circuits. To understand circuits, it is
`
`important to understand the concepts of charge, voltage, current, energy, power,
`
`resistance, and impedance. See Ex.-2038 ¶¶38-43.
`
`Charge: In a circuit, there are two physical types of charge – positive charge
`
`and negative charge. Protons have a positive charge (+) and electrons have a negative
`
`charge (–). See Ex.-2038 ¶¶44-46.
`
`Circuits operate based on the movement of electrons and the movement of
`
`charge transfers energy. Charge may build up to establish a voltage signal. Here, a
`
`voltage signal refers to information that is almost entirely conveyed as a voltage.
`
`Alternatively, the movement of charge, the rate of which is current, may itself be the
`
`signal. Most circuits convey information, i.e., present signals, as a voltage or as a
`
`current. Ex.-2038 ¶47.
`
`Voltage: Voltage is the difference in an electron’s potential energy, per unit
`
`charge, between two points. In other words, voltage is the amount of potential
`
`(electrical) energy available, per unit charge. Negative charges (electrons) are pulled
`
`towards higher voltages, while positive charges (protons) are pulled towards lower
`
`voltages. Ex.-2038 ¶¶48.
`
`
`
`9
`
`

`

`
`
`Electric current: An electric current is the movement/flow of charge in a
`
`circuit (in a conductor or into, out of, or through an electrical component). Current
`
`(the net rate of movement of positive charges) flows from positive voltage to
`
`negative voltage. Ex.-2038 ¶49.
`
`Electric energy: Electric energy is energy that results from the movement of a
`
`charge in a circuit. The faster the charges move and the more charges that move, the
`
`more energy they carry. The only way to transfer energy is by transferring charge.
`
`So, movement of a charge indicates movement of energy. Ex.-2038 ¶¶50-52.
`
`Energy is not the same as voltage. Energy and voltage are used in circuits in
`
`different ways. Ex.-2038 ¶53.
`
`Power: Power is the amount of energy transferred per unit time. Power is the
`
`average rate at which energy is transferred by charges. Ex.-2038 ¶54.
`
`Resistance: Resistance is a measure of the difficulty of passing an electric
`
`current through a conductor. Ex.-2038 ¶55.
`
`Impedance: Impedance is the measure of the opposition that a circuit presents
`
`to a current when a voltage is applied. Impedance is related to, but not the same as,
`
`resistance. Resistance is one component of impedance. In addition, impedance
`
`describes the ability of a circuit element to store and/or return electrical energy
`
`(referred to as reactance). A circuit component with high resistance has high
`
`impedance. Ex.-2038 ¶56.
`
`
`
`10
`
`

`

`
`
`B. Circuit diagrams.
`
`Circuit designers/engineers use circuit diagrams to illustrate how circuit
`
`elements are connected together. Ex.-2038 ¶64.
`
`
`
`The exemplary circuit diagram above shows various circuit elements and how
`
`they can be connected together by wires/traces (shown by lines). Transistors,
`
`capacitors, and resistors shown in the diagram above are described below. Ex.-2038
`
`¶65.
`
`Each circuit element has a particular effect(s) on voltage, current, charge, and
`
`energy. By combining circuit elements in different numbers and/or ways and using
`
`circuit elements that have certain values, circuit designers/engineers can create
`
`circuits that perform a wide variety of different functions. Ex.-2038 ¶66.
`
`C. Transistors
`
`A transistor is a semiconductor device used to switch, detect, or amplify
`
`electronic signals and electrical power. Ex.-2038 ¶67. A transistor has at least three
`
`terminals for connection to an external circuit. Key to the functionality of a transistor
`
`
`
`11
`
`

`

`
`
`is that a controlling voltage or current at one terminal can control a current between
`
`two of the other terminals. Ex.-2038 ¶68.
`
`Some types of transistors can be used as a switch. Transistors, however, can
`
`also be used to provide other functions (e.g. amplification). Whether a transistor is
`
`used as a switch or performs another function depends on the signals applied to the
`
`terminals of the transistor, and on the circuit in which the transistor is embedded.
`
`Ex.-2038 ¶69.
`
`A field-effect transistor (FET) is one type of transistor. Not all transistors are
`
`FETs. The symbol for one type of FET is shown below. Ex.-2038 ¶¶69-71.
`
`A FET has three terminals: (1) source (S), (2) drain (D) and (3) gate (G). In a
`
`FET, a voltage at the gate (G) controls the current flow between the drain (D) and
`
`
`
`source (S). Ex.-2038 ¶72.
`
`D. Capacitors.
`
`A capacitor is one type of circuit element used to store (accumulate) energy.
`
`A capacitor stores electric charge in an electric field by separating charges over a
`
`distance. Ex.-2038 ¶¶73-75.
`
`
`
`12
`
`

`

`
`
`
`
`As shown above left, a capacitor is constructed with two conductive (metal)
`
`plates with a dielectric (or air) separating the plates by a distance d. The dielectric/air
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`does not allow current to pass. The symbol for one type of capacitor is shown above
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`right. See Ex.-2038 ¶¶76-83.
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`A capacitor can be used in different ways within a circuit. In particular, the
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`capacitance of a capacitor and the electric elements connected to a capacitor dictate
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`how the capacitor operates in a circuit. That a capacitor can be used in different ways
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`within a circuit is key to understanding why the claimed invention of the ’444 patent
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`is distinguishable from Petitioners’ prior art references. Ex.-2038 ¶84.
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`E. Resistor.
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`A resistor is a circuit element that introduced resistance into a circuit. The
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`symbol for one type of resistor is shown below. Ex.-2038 ¶85.
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`Resistors are used, for example, to reduce current flow, adjust signal levels,
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`divide voltages, bias active elements, and terminate transmission lines. Ex.-2038
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`¶86.
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`F. Differential amplifier.
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`A differential amplifier is an electrical element that amplifies voltage or
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`current. It has two input terminals and either one or two output terminals. The
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`symbol for a single-output differential amplifier is shown below. See Ex.-2038 ¶¶89-
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`91.
`
`G. Electrical load and impedance.
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`
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`Connecting a load to a capacitor affects the operation of the capacitor and,
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`thus, the way the capacitor is used in a circuit. Ex.-2038 ¶92.
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`An electrical load is an electrical element or portion of a circuit that absorbs
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`power and converts it into a desired form. Whereas a power source supplies energy,
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`a load extracts/uses energy. For example, a resistor is a type of load and a differential
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`amplifier is another type of load. Ex.-2038 ¶93.
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`There are high impedance loads and low impedance loads. A high impedance
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`load inhibits current from moving in a circuit and absorbs very little electrical
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`energy. A low impedance load provides little constraint to current moving in a circuit
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`and absorbs electrical energy. Thus, a low impedance load must have a low
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`resistance, whereas a load with a high resistance is a high impedance load. Ex.-2038
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`¶94.
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`Since a load is connected to the output of other circuitry, the circuitry (e.g.,
`
`capacitor, source, transistors) is said to be driving the load (when substantial current
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`flows from the circuitry to the load). For example, when circuitry is connected to a
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`low impedance load, the circuitry is said to be driving a low impedance load. Ex.-
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`2038 ¶95.
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`VII. VOLTAGE V. ENERGY SAMPLING
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`A. Voltage sampling.
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`At the time of the invention of the ’444 patent (late 1990s through March
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`2000), a technology being considered for direct down-conversion (to recover the
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`baseband signal directly from the RF signal without using IF) was voltage sampling.
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`There are different types of voltage sampling systems (e.g., sample-and-hold). Ex.-
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`2038 ¶¶144-147.
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`All such systems, however, attempted to replicate the voltage of the RF signal.
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`It was thought that the best (and most accurate) way to replicate the voltage of the
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`RF signal, while distorting the RF signal as little as possible, was to sample the
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`voltage of the RF signal itself. Based on numerous readings of the voltage, voltage
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`sampling systems could derive a baseband signal (which is a representation of the
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`baseband signal sent from a transmitting device). Ex.-2038 ¶145.
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`The diagram below illustrates an exemplary voltage sampling system. Ex.-
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`2038 ¶148.
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`
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`As shown above, the system includes a switch (blue), a holding element
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`(capacitor) (pink), and a high impedance load (orange). The ’444 patent specifically
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`reserves the term “holding” module/element to refer to an element (e.g., capacitor)
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`used in a voltage sampling system. Section VIII.B.2; Ex.-2038 ¶¶149-157.
`
`B.
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`Energy Sampling.
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`Energy transfer (energy sampling) was/is a fundamentally different and
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`competing method to voltage sampling. Ex.-2038 ¶¶158-159. The diagram below
`
`illustrates ParkerVision’s implementation of an energy transfer (energy sampling)
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`system. Ex.-2038 ¶161.
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`ParkerVision’s energy transfer system includes a switch (blue), a storage
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`element (capacitor) (orange), and a low impedance load (yellow). Ex.-2038 ¶162.
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`The ’444 patent specifically reserves the term “storage” module/element to refer to
`
`an element (e.g., capacitor) used in an energy sampling system. Section VIII.B.1;
`
`Ex.-2038 ¶163.
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`Using a low impedance load is significant in the design of ParkerVision’s
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`energy transfer system. Section VIII.B.1; Ex.-2038 ¶¶164-174.
`
`C. Key take-aways.
`
`While both energy sampling and voltage sampling use similar components
`
`(e.g., switches, capacitors, and loads), these components are used in different ways
`
`in a circuit to create a desired result. See Ex.-2038 ¶¶175-179.
`
`D.
`
`Secondary considerations.
`
`In the late 1990s through March 2000, there was a long-felt need for a solution
`
`for direct down-conversion. Numerous companies were exploring how to directly
`
`down-convert but failed to figure out a way to do so in a commercially viable way.
`
`At the time, heterodyning was commercially used but had problems (e.g., high
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`energy requirements, noisy, susceptible to interference, required expensive/bulky
`
`external components). The industry was looking to voltage sampling and mixing
`
`using nonlinear or time-varying elements to solve the direct down-conversion
`
`problem. But these solutions had their own problems (e.g., too much noise) and were
`
`never widely implemented commercially (if at all). Ex.-2038 ¶¶234-235.
`
`Using energy sampling at the time was counter-intuitive and against the
`
`thinking in the industry, which was looking to replicate the voltage of the RF signal
`
`and use that voltage to derive a baseband signal. Energy sampling did not accurately
`
`replicate the voltage of an RF signal. Ex.-2038 ¶¶237-238.
`
`Energy sampling had a number of unexpected results: an energy sampling
`
`downconverter (1) enables selection of just one channel from a band, (2) uses enough
`
`of the available RF energy so that the desired baseband signal stands out from the
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`noise which, in turn, improves RF receiver performance, lowers power consumption,
`
`allows for reduction/elimination of expensive/bulky external components, and (3) is
`
`surprisingly linear (at the time of the invention, the common understanding was that
`
`competing mixing technologies were nonlinear). Ex.-2038 ¶¶239-242.
`
`Unknown at this time by industry and academia was that, by using an energy
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`transfer system, RF receivers could be built smaller, cheaper and with improved
`
`performance. In the late 1990s, Qualcomm recognized the significance of
`
`ParkerVision’s energy transfer (energy sampling) system as set forth in challenged
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`claims. Subsequently, Qualcomm and others in the industry transitioned away from
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`superheterodyne receivers and mixer technology and began to use the energy
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`transfer system set forth in the challenged claims. Ex.-2038 ¶¶243-245.
`
`VIII. THE ’444 PATENT
`
`A. Overview
`
`The ’444 patent relates to a system and method to up-convert and down-
`
`convert an electromagnetic signal (radio frequency signal). Ex.-1001, 2:20-22, 25-
`
`28; 9:27-29; 13:33-34. Since claims 2-4 only relate to down-conversion, the below
`
`discussion focuses on down-conversion.
`
`
`
`Figure 20A (above left) shows the basic configuration of a universal
`
`frequency down-conversion (UFD) module of the invention, which is also referred
`
`to as an aliasing module. Id., 9:43-48. Aliasing (UFD) module 2000 (yellow)
`
`includes (1) a universal frequency translation (UFT) module 2002 (implemented a