IPR2020-01265
`U.S. Patent No. 7,110,444
`Patent Owner’s Response
`
`
`
`UNITED STATES PATENT AND TRADEMARK OFFICE
`____________________________
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`____________________________
`Intel Corporation
`Petitioner
`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. IPR2020-01265
`__________________________________________________________________
`PATENT OWNER’S RESPONSE TO PETITION FOR
`INTER PARTES REVIEW OF UNITED STATES PATENT NO. 7,110,444
`
`

`

`TABLE OF CONTENTS
`
`Page
`
`I.
`
`II.
`
`THE PETITION PURPOSEFULLY OMITS CRITICAL
`INFORMATION. ............................................................................................ 1
`CLAIM CONSTRUCTION IN THE PARTIES’ RELATED
`LITIGATION .................................................................................................. 3
`III. LEVEL OF ORDINARY SKILL IN THE ART ............................................. 4
`IV. GENERAL OVERVIEW OF WIRELESS TECHNOLOGY ......................... 4
`A. Wired communications. ........................................................................ 5
`B. Wireless Communications. .................................................................... 5
`C.
`Frequency. ............................................................................................. 6
`D. Up-conversion. ...................................................................................... 7
`E.
`Down-conversion. ................................................................................. 8
`IMPORTANT CONCEPTS RELATED TO WIRELESS
`TECHNOLOGY .............................................................................................. 9
`A.
`Basic circuit concepts. ......................................................................... 10
`B.
`Circuit diagrams. ................................................................................. 12
`1.
`Transistors ................................................................................. 13
`2.
`Capacitors. ................................................................................. 14
`3.
`Resistor. ..................................................................................... 14
`4.
`Differential amplifier. ............................................................... 15
`Electrical load, high impedance loads and low impedance loads. ...... 15
`Baseband signals, carrier signals, modulation, up-conversion. .......... 16
`Down-conversion. ............................................................................... 17
`
`V.
`
`C.
`D.
`E.
`
`i
`
`

`

`VI. VOLTAGE SAMPLING V. ENERGY SAMPLING ................................... 19
`A.
`Sample-and-hold (voltage sampling). ................................................. 19
`B.
`Energy Sampling. ................................................................................ 21
`VII. THE ’444 PATENT ....................................................................................... 23
`A.
`Overview ............................................................................................. 23
`B.
`The patent discloses two fundamental different and competing
`systems for down-conversion. ............................................................. 31
`1.
`Energy transfer (energy sampling). .......................................... 33
`2.
`Sample and hold (voltage sampling). ....................................... 38
`Prosecution history. ............................................................................. 42
`C.
`VIII. CLAIM CONSTRUCTION .......................................................................... 45
`A.
`The District Court’s construction. ....................................................... 45
`B.
`Intel failed to provide a construction for “storage element” and
`“switch.” .............................................................................................. 45
`The District Court rejected Intel’s construction of “storage
`element.” .............................................................................................. 46
`A “storage element” is an element of “energy transfer system.” ........ 46
`Intel recognizes that “frequency down-conversion module” is
`not a means-plus-function term. .......................................................... 50
`Intel has taken inconsistent position of “subtractor module” in the
`Petition and District Court case; Intel’s construction is wrong. ......... 52
`IX. OVERVIEW OF THE ALLEGED PRIOR ART .......................................... 53
`A.
`U.S. Patent No. 6,230,000 to Tayloe (“Tayloe”) ................................ 53
`B.
`Texas Instruments Datasheet for SN74CBT3253 DUAL 1-OF-4
`FET MULTIPLEXER/DEMULTIPLEXER (“TI Datasheet”) ........... 70
`U.S. Patent No. 4,985,647 to Kawada (“Kawada”) ............................ 71
`
`D.
`E.
`
`C.
`
`F.
`
`C.
`
`ii
`
`

`

`X.
`
`INTEL HAS NOT SHOWN A REASONABLE LIKEKIHOOD THAT
`CLAIM 3 OF THE ’444 PATENT IS UNPATENTABLE UNDER
`35 U.S.C. § 103. ............................................................................................. 72
`A.
`GROUND 1: Claim 3 – Tayloe in View of the TI Datasheet. .......... 72
`B.
`GROUND 2: Claim 3 – Tayloe in View of Kawada .......................... 76
`XI. CONCLUSION .............................................................................................. 76
`
`iii
`
`

`

`TABLE OF AUTHORITIES
`
` Page(s)
`
`Cases
`Apple Inc. v. Andrea Elecs. Corp.,
`949 F.3d 697 (Fed. Cir. 2020) ............................................................................ 46
`Baran v. Med. Device Techs., Inc.,
`616 F.3d 1309 (Fed. Cir. 2010) .......................................................................... 46
`TEK Global, S.R.L. v. Sealant Sys. Int’l, Inc.,
`920 F.3d 777 (Fed. Cir. 2019) ............................................................................ 53
`Williamson v. Citrix Online, LLC,
`792 F.3d 1339 (Fed. Cir. 2015) (en banc) .................................................... 51, 52
`Statutes
`35 U.S.C. § 103 ........................................................................................................ 72
`35 U.S.C. §112 ....................................................................................... 50, 51, 52, 53
`
`
`
`iv
`
`

`

`Exhibit No.
`2001
`
`2002
`
`2003
`
`2004
`
`2005
`
`2006
`
`2007
`2008
`
`2009
`
`2010
`
`2011
`
`2012
`
`2013
`
`2014
`2015
`2016
`2017
`
`PATENT OWNER’S EXHIBIT LIST
`Description
`Complaint, ParkerVision, Inc. v. Intel Corp., No. 6:20-
`cv-00108-ADA
`Complaint, ParkerVision, Inc. v. Intel Corp., No. 6:20-
`cv-00562-ADA
`Scheduling Order, ParkerVision, Inc. v. Intel Corp., No.
`6:20-cv-00108-ADA
`Published Interview of Judge Albright, IAM (Apr. 7,
`2020)
`Docket Order, Kerr Machine Co. d/b/a Kerr Pumps v.
`Vulcan Industrial Holdings, LLC, No. 6:20-cv-00200
`(W.D. Tex. Aug. 2, 2020)
`Relevant Excerpts Defendant’s Preliminary Invalidity
`Contentions, filed in ParkerVision, Inc. v. Intel Corp.,
`No. 6:20-cv-00108-ADA
`U.S. Patent No. 6,061,551
`Graf, R.F., 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
`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
`Claim Construction Order, ParkerVision, Inc. v. Intel
`Corp., No. 6:20-cv-108-ADA (W.D. Tex.)
`B. Razavi, “CMOS RF receiver design for wireless
`LAN applications,” IEEE Radio and Wireless
`Conference, pp. 275-280, Aug. 1999
`Qualcomm Email dated Feb. 2, 1999
`Qualcomm Email dated Oct. 7, 1998
`Qualcomm Email dated Feb. 4, 1999
`Lawrence E. Larson, RF and Microwave Circuit Design
`for
`
`v
`
`

`

`Wireless Communications (Artech House 1996)
`Sedra/Smith, Microelectronic Circuits (Oxford
`University Press 1998)
`Kevin McClaning and Tom Vito, Radio Receiver
`Design (Noble Publishing 2000)
`Qualcomm Email dated Aug. 11, 1998
`Declaration of Dr. Michael Steer
`
`2018
`
`2019
`
`2020
`2021
`
`
`
`
`
`vi
`
`

`

`Pursuant to 37 C.F.R. § 42.120, ParkerVision, Inc. (“ParkerVision”) hereby
`
`submits this Patent Owner Response to the Petition for Inter Partes Review of U.S.
`
`Patent No. 7,110,444 (“the ’444 patent”) filed by Intel Corporation (“Intel”). For at
`
`least the reasons set forth herein, the challenged claim 3 is patentable.1
`
`I.
`
`THE PETITION PURPOSEFULLY OMITS CRITICAL
`INFORMATION.
`This case relates to how wireless devices (e.g., cell phones) process radio
`
`signals. And context is key here. The patent discusses two technologies for
`
`processing radio signals – (1) energy transfer (energy sampling) and (2) sample-and-
`
`hold (voltage sampling). The difference in these technologies is significant. Indeed,
`
`energy transfer (energy sampling) and sample-and-hold (voltage sampling) are
`
`fundamentally different and competing technologies. And challenged claim 3 is
`
`directed to only one of these technologies – energy transfer (i.e., energy sampling).
`
`Intel purposefully omits this critical distinction from the Petition (and Intel’s
`
`expert declaration) because it presents a significant problem for Tayloe – Intel’s
`
`main prior art reference in the Petition (which is cited on the face of the ’444 patent).
`
`1 The Petition challenges claims 1, 3, and 5 of the ’444 patent. ParkerVision intends
`
`to disclaim claims 1 and 5 of the ’444 patent in order to focus the dispute in the
`
`Petition on a critical distinguishing feature over the prior art, which is found in
`
`claim 3 – a “storage element.”
`
`1
`
`

`

`Unlike claim 3, Tayloe discloses a voltage sampling system. Intel attempts to
`
`conceal this issue when describing the ’444 patent and Tayloe.2
`
`Tellingly, Intel attempted to use this same strategy (ignoring how the patent
`
`distinguishes energy sampling and voltage sampling) in the parties related, pending
`
`litigation in the U.S. District Court for the Western District of Texas. ParkerVision,
`
`Inc. v. Intel Corp., Case No. 6:20-cv-00108. The District Court, however, saw right
`
`through Intel’s gamesmanship.
`
`Claim 3 of the ’444 patent recites a “storage element” – a term that the ’444
`
`patent specifically reserved to refer to an element of an energy transfer system. As
`
`such, after significant briefing and oral argument, the District Court construed
`
`“storage element” to be “an element of an energy transfer system that stores non-
`
`negligible amounts of energy from an input electromagnetic signal.”3 ParkerVision
`
`believes that the same construction should be adopted for this proceeding.4
`
`
`2 The other prior art references that Intel relies on merely deal with a type of switch
`
`configuration that could be used with Tayloe. But these references do not change the
`
`very nature of Tayloe as being a sample-and-hold (voltage sampling) system.
`
`3 Unless otherwise noted, all emphasis has been added.
`
`4 The PTAB follows the same claim construction standard as the Court. See 83 Fed.
`
`Reg. 51,340 (Oct. 11, 2018) (revising 37 C.F.R. § 42.100(b)). While the Board is
`
`
`
`2
`
`

`

`None of Intel’s prior art references in the Petition, however, is an energy
`
`transfer system. As such, the cited prior art references do not disclose, teach or
`
`suggest using a “storage element” i.e., “an element of an energy transfer system.”
`
`Intel’s Petition, therefore, fails to make out a prima facie case of obviousness for the
`
`challenged claim of the ’444 patent. ParkerVision respectfully requests a Final
`
`Written Decision affirming the validity of the ’444 patent.
`
`II. CLAIM CONSTRUCTION IN THE PARTIES’ RELATED
`LITIGATION
`On February 11, 2020, ParkerVision filed suit against Intel for infringement
`
`of the ’444 patent in the U.S. District Court for the Western District of Texas (Case
`
`No. 6:20-cv-00108) (“District Court”). From October through December 2020, the
`
`parties each filed three claim construction briefs. Intel filed a Markman tutorial. On
`
`January 24, 2021, the District Court issued its preliminary claim constructions. On
`
`January 26, 2021, the District Court held a Markman hearing. On January 28, 2021,
`
`the District Court issued its final claim construction Order.
`
`The District Court construed “storage element” in claim 3 of the ’444 patent,
`
`which is the subject of the Petition. In particular, after considering arguments that
`
`energy transfer (energy sampling) and sample-and-hold (voltage sampling) are
`
`
`not bound by the Court’s claim construction ruling, it is informative. See 37 C.F.R.
`
`§ 42.100(b).
`
`
`
`3
`
`

`

`fundamentally different, the District Court held that the term “storage element” refers
`
`to “an element of an energy transfer system.”
`
`District Court’s construction
`Term
`“storage element” “an element of an energy transfer system that stores non-
`negligible amounts of energy from an input electromagnetic
`signal”
`
`
`Ex. 2012, Claim Construction Order dated January 28, 2021, at 5.
`
`While this Board is not bound by the District Court’s constructions,
`
`ParkerVision submits that the Board should adopt the District Court’s constructions.
`
`III. LEVEL OF ORDINARY SKILL IN THE ART
`A person of ordinary skill in the art (“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. Ex. 2021 ¶24.
`
`IV. GENERAL OVERVIEW OF WIRELESS TECHNOLOGY
`The ’444 patent relates to wireless communication and, more particularly, to
`
`frequency up-conversion and down-conversion of electromagnetic (EM) signals.
`
`Ex. 2021 ¶26.
`
`
`
`4
`
`

`

`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.
`
`2021 ¶27.
`
`Bob
`
`Alice
`
`
`
`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. 2021 ¶28.
`
`B. Wireless Communications.
`Similar to wired communications, in wireless communications, low frequency
`
`audio signals are converted into electrical signals. But instead of travelling through
`
`wires, the signals are transmitted through air as radio waves (electromagnetic (EM)
`
`waves). Ex. 2021 ¶29.
`
`
`
`5
`
`

`

`1-igh ftt qutncysi1;,u1 (AF')
`
`-NM
`
`
`
`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
`
`and because high frequency antennas can physically fit within small devices such as
`
`cellular phones. Ex. 2021 ¶30.
`
`Bob
`
`(Audio)
`
`Alice
`
`
`
`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. 2021 ¶31.
`
`Frequency.
`C.
`Frequency is the number of cycles of a wave per unit time (second). Ex. 2021
`
`¶32.
`
`
`
`6
`
`

`

`High frequency
`
`Low frequency
`
`short wavelength M
`I\ I\ I\ I\ I\ I\ I\ I\ {\ I\ {\ I\
`/ V V V V V V V Vll \TV v ime or distance
`
`IOng wavelength
`
`I
`I
`(\ (\ (\ (\
`
`]V ' \ . . ; ' \ . . ;\::_me or distance
`
`
`
`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. 2021 ¶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. 2021 ¶34.
`
`BilstlN!oo
`(/WdlOI
`
`Modulated
`Canie:r Signal (1RFj
`
`
`
`
`
`7
`
`

`

`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
`
`baseband (audio) signal (above right).5 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. 2021
`
`¶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 is referred to as “down-conversion” because a high frequency signal is being
`
`down-converted to a low frequency signal. Ex. 2021 ¶36.
`
`
`5 This type of modification is referred to as amplitude modulation. But other types
`
`of modulation can be used, which involve modifying other properties of the carrier
`
`signal, such as frequency or phase. Ex. 2021 ¶35 n.1.
`
`
`
`8
`
`

`

`..
`
`
`
`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 claim 3 of the ’444 patent.6 Ex. 2021 ¶37.
`
`V.
`
`IMPORTANT CONCEPTS RELATED TO WIRELESS
`TECHNOLOGY
`ParkerVision’s expert, Dr. Michael Steer, provides a detailed discussion of
`
`wireless technology in his expert declaration. See Ex. 2021 ¶¶38-171. For the
`
`Board’s convenience, ParkerVision includes portions of Dr. Steer’s discussion
`
`below to highlight some key concepts related to wireless technology.
`
`
`6 While Section IV provides an overview of the technology in connection with
`
`voice/audio signals, it should be understood that this is for illustrative purposes only.
`
`The technology of the ’444 patent can be used to up-convert or down-convert any
`
`type of electromagnetic signal that carries information, such as video, web, and other
`
`types of data. Ex. 2021 ¶37 n.2.
`
`
`
`9
`
`

`

`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. Ex. 2021 ¶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 (–). Ex. 2021 ¶44.
`
`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. 2021 ¶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. 2021 ¶48.
`
`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
`
`
`
`10
`
`

`

`(the net rate of movement of positive charges) flows from positive voltage to
`
`negative voltage. Ex. 2021 ¶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. 2021 ¶50.
`
`Energy is not the same as voltage. Energy and voltage are used in circuits in
`
`different ways. Ex. 2021 ¶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. 2021 ¶54.
`
`Resistance: Resistance is a measure of the difficulty of passing an electric
`
`current through a conductor. Ex. 2021 ¶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. 2021 ¶56.
`
`
`
`11
`
`

`

`B. Circuit diagrams.
`Circuit designers/engineers use circuit diagrams to illustrate how circuit
`
`elements are connected together. Ex. 2021 ¶64.
`
`Input
`(!; ~,
`
`. .
`
`1M
`
`+12Vdc
`
`Transistor
`
`Resistor
`Node
`
`Capacitor
`
`t=.
`
`
`The exemplary circuit diagram above shows various circuit elements and how
`
`•12Vdc
`
`they can be connected together by wires/traces (shown by lines). Transistors,
`
`capacitors, and resistors shown in the diagram above are described below.7 Ex. 2021
`
`¶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. 2021 ¶66.
`
`
`7 As shown above, “ground” (shown as an upside-down triangle) is a connection to
`
`a fixed potential which is defined as zero volts and a “node” (shown as a dot) is a
`
`location where three or more wires/leads come together. Ex. 2021 ¶65.
`
`
`
`12
`
`

`

`Transistors
`1.
`A transistor is a semiconductor device used to switch or amplify electronic
`
`signals and electrical power. A transistor has at least three terminals for connection
`
`to an external circuit. Key to the functionality of a transistor is that a controlling
`
`voltage or current at one terminal can control a current between two of the other
`
`terminals. Ex. 2021 ¶67.
`
`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. 2021 ¶68.
`
`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. 2021 ¶¶69-70.
`
`D
`
`~
`s
`
`
`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. 2021 ¶71.
`
`
`
`13
`
`

`

`Capacitors.
`2.
`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. 2021 ¶72.
`
`A
`
`Conductive plates
`ld
`T
`
`Dielectric
`
`_l
`T
`
`
`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
`
`does not allow current to pass. Ex. 2021 ¶75. The symbol for one type of capacitor
`
`is shown above right. Ex. 2021 ¶73.
`
`A capacitor can be used in different ways within a circuit. In particular, the
`
`capacitance of a capacitor and the electric elements connected to a capacitor dictate
`
`how the capacitor operates in a circuit. That a capacitor can be used in different ways
`
`within a circuit is key to understanding why the claimed invention of the ’444 patent
`
`is distinguishable from Intel’s prior art references. Ex. 2021 ¶83.
`
`Resistor.
`3.
`A resistor is a circuit element that introduced resistance into a circuit. The
`
`symbol for one type of resistor is shown below. Ex. 2021 ¶84.
`14
`
`
`
`

`

`
`Resistors are used, for example, to reduce current flow, adjust signal levels,
`
`divide voltages, bias active elements, and terminate transmission lines. Ex. 2021 ¶85.
`
`Differential amplifier.
`4.
`A differential amplifier is an electrical element that amplifies voltage or
`
`current. It has two input terminals and either one or two output terminals. The
`
`symbol for a single-output differential amplifier is shown below. Ex. 2021 ¶¶88-89.
`
`+
`
`
`C. Electrical load, high impedance loads and low impedance loads.
`The concept of a “load” is a key concept to the claimed invention of the ’444
`
`patent. Connecting a load to a capacitor affects the operation of the capacitor and,
`
`thus, the way the capacitor is used in a circuit. Ex. 2021 ¶91.
`
`An electrical load is an electrical element or portion of a circuit that absorbs
`
`power and converts it into a desired form. Ex. 2008 at 431. Whereas a power source
`
`supplies energy, a load extracts/uses energy. For example, a resistor is a type of load
`
`and a differential amplifier is another type of load. Ex. 2021 ¶92.
`
`There are high impedance loads and low impedance loads. A high impedance
`
`load inhibits current from moving in a circuit and absorbs very little electrical
`
`
`
`15
`
`

`

`energy. A low impedance load provides little constraint to current moving in a circuit
`
`and absorbs electrical energy. Thus, a low impedance load must have a low
`
`resistance, whereas a load with a high resistance is a high impedance load. Ex. 2021
`
`¶93.
`
`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
`
`flows from the circuitry to the load). For example, when circuitry is connected to a
`
`low impedance load, the circuitry is said to be driving a low impedance load. Ex.
`
`2021 ¶94.
`
`D. Baseband signals, carrier signals, modulation, up-conversion.
`Information such as voice or digital data cannot be directly transmitted
`
`through air because such information exists at a low frequency. This low-frequency
`
`signal is referred to as “baseband,” a “baseband signal” or at a “baseband frequency.”
`
`Ex. 2021 ¶103.
`
`In order to transmit information over air, a wireless device must transform a
`
`baseband signal (which carries the information) to an RF signal (a higher frequency
`
`signal). Since the RF signal is used to carry the information over the air, the RF
`
`signal is referred to as a “carrier signal.” Ex. 2021 ¶104.
`
`
`
`16
`
`

`

`N l ◄ned
`c.-,_11!'1
`
`..
`
`
`In particular, in order to transport the baseband signal, a transmitting wireless
`
`device modifies (modulates) the carrier signal. The carrier signal without modulation
`
`is also called an “unmodulated carrier 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 baseband signal (above
`
`right). The modified signal is referred to as a “modulated carrier signal.” In this
`
`specific example, the amplitude is being modulated. The process is referred to as
`
`“modulation” or “up-conversion” because the low frequency signal is being up-
`
`converted to a high frequency signal. Ex. 2021 ¶105.
`
`E. Down-conversion.
`As shown in the diagram below, in order for a receiving wireless device (e.g.,
`
`cellular phone) to recover the baseband signal (and the information that it carries)
`
`from the modulated carrier signal, the receiving wireless device must transform the
`
`modulated carrier signal back to a baseband signal. This process is referred to
`
`“demodulation” or “down-conversion” because a high frequency signal is being
`
`down-converted to a low frequency signal. Ex. 2021 ¶113.
`
`
`
`17
`
`

`

`
`Demodulation is the inverse of modulation and results in the extraction of the
`
`baseband signal from the modulated carrier signal. Ex. 2021 ¶114.
`
`Today, a receiver can down-convert from an RF signal to a baseband signal
`
`in one stage or multiple stages. In a one stage configuration, the RF signal is directly
`
`converted to a baseband signal. This is referred to as direct down-conversion. In a
`
`multiple stage configuration, the RF signal is first down-converted to an intermediate
`
`frequency (IF) signal (which is at a lower frequency than the RF signal but higher
`
`frequency than a baseband signal) and the IF signal is then down-converted to a
`
`baseband signal. Ex. 2021 ¶120.
`
`At the time of the invention of the ’444 patent, in the late 1990s through March
`
`2000, however, direct down-conversion was not well developed. At that time,
`
`receivers generally used multiple stage conversion. There was, however, significant
`
`research and development dedicated to finding ways to accomplishing direct down-
`
`conversion using a single conversion stage. Many companies failed in this endeavor
`
`and the solutions that were developed had significant technical and practical
`
`limitations. Ex. 2021 ¶121.
`
`
`
`18
`
`

`

`VI. VOLTAGE SAMPLING V. ENERGY SAMPLING
`
`With the technical background above, this section explains the differences
`
`between voltage sampling and energy sampling. Indeed, the difference between
`
`these technologies is critical to understanding why Intel’s prior art fails to invalidate
`
`challenged claim 3 of the ’444 patent.
`
`Claim 3 covers only energy sampling. On the other hand, Tayloe (Intel’s main
`
`prior art reference) pertains to voltage sampling. But energy sampling and voltage
`
`sampling are fundamentally different and competing systems. And these differences
`
`are why Intel’s prior art fails to disclose a “storage element” of challenged claim 3.
`
`A.
`
`Sample-and-hold (voltage sampling).
`
`At the time of the invention of the ’444 patent, in the late 1990s through March
`
`2000, a technology being considered for direct down-conversion (to recover the
`
`baseband signal directly from the RF signal without using IF) was sample-and-hold
`
`(voltage sampling). There are different types of sample-and-hold (voltage sampling)
`
`systems. Ex. 2021 ¶¶141-144.
`
`All such systems, however, attempted to replicate the voltage of the RF signal
`
`with as little distortion as possible. In the late 1990s through March 2000, it was
`
`thought that the best (and most accurate) way to replicate the voltage of the RF
`
`signal, while distorting the RF signal as little as possible, was to sample the voltage
`
`of the RF signal itself. Based on numerous readings of the voltage, sample-and-hold
`
`
`
`19
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`

`

`(voltage sampling) systems could derive a baseband signal (which is a representation
`
`of the baseband signal sent from a transmitting device). Ex. 2021 ¶¶142.
`
`The diagram below illustrates an exemplary sample-and-hold (voltage
`
`sampling) system.
`
`Switch
`
`l
`
`___ /
`
`,!o ---r--------il.;.H_iglil,h~ Im peda nee
`Load
`
`Holding element
`
`
`
`As shown above, a sample-and-hold (voltage sampling) system includes a
`
`switch (blue), a holding element (capacitor) (pink) coupled to ground, and a high
`
`impedance load (orange). The ’444 patent specifically reserves the term “holding”
`
`module/element to refer to an element (e.g., capacitor) used in a sample-and-hold
`
`(voltage sampling) system because, as discussed in Section VI.B.2 below, the use of
`
`a high impedance load causes the capacitor to hold energy (i.e., prevent energy in
`
`the capacitor from being discharged to form the down-converted signal – the
`
`discharged energy itself does