LG Electronics Inc v. ParkerVision Inc

1. Case Identification

• Case #: IPR2022-00245
• Patent #: 7,110,444
• Filed: December 17, 2021
• Petitioner(s): LG Electronics Inc.
• Patent Owner(s): ParkerVision, Inc.
• Challenged Claims: 2-4

2. Patent Overview

• Title: Wireless Modem Apparatus for Frequency Down-Conversion
• Brief Description: The ’444 patent discloses a wireless modem receiver apparatus for down-converting a high-frequency radio frequency (RF) signal to a lower-frequency baseband signal. The claimed architecture uses two parallel frequency down-conversion modules to process an input signal and a subtractor module to combine their outputs.

3. Grounds for Unpatentability

Ground 1: Obviousness over Tayloe and TI Datasheet - Claims 2 and 3 are obvious over Tayloe in view of the TI Datasheet.

• Prior Art Relied Upon: Tayloe (Patent 6,230,000) and TI Datasheet (a May 1998 datasheet for the SN74CBT3253D multiplexer/demultiplexer).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Tayloe disclosed all elements of the challenged claims. Tayloe taught a direct conversion receiver with two frequency down-conversion paths (the 0° and 180° paths) and a "summing amplifier" that functions as the claimed subtractor module. Each down-conversion path in Tayloe comprised a commutating switch and capacitors, analogous to the claimed "down-conversion modules." The TI Datasheet, which Tayloe expressly referenced as a suitable implementation for its commutating switch, provided the specific structure of a multiplexer/demultiplexer with multiple internal switches. Petitioner asserted that Tayloe's disclosure of sampling "at the frequency of the input signal" satisfied the "under-samples" limitation of claim 2, as this rate is less than or equal to twice the input signal's frequency. The combination of Tayloe and the TI Datasheet also taught the "switch and a storage element" (capacitor) required by claim 3.
  • Motivation to Combine: A person of ordinary skill in the art (POSITA) would combine Tayloe and the TI Datasheet because Tayloe explicitly identified the specific TI component described in the datasheet as a suitable analog multiplexer for implementing its commutating switch. This express reference provided a clear motivation to consult the datasheet for implementation details.
  • Expectation of Success: A POSITA would have a high expectation of success because they would be implementing a disclosed component (from the TI Datasheet) directly into the system for which it was recommended (Tayloe's receiver). This represented a simple substitution of a known element to achieve predictable results.

Ground 2: Obviousness over Lam, Enz, and Tayloe - Claims 2-4 are obvious over Lam in view of Enz and Tayloe.

• Prior Art Relied Upon: Lam (Patent 5,937,013), Enz (a 1996 IEEE publication), and Tayloe (Patent 6,230,000).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner contended that Lam disclosed a direct conversion receiver that down-converts an RF signal into in-phase (I) and negative in-phase (-I) components using "sampling circuits." Lam explicitly stated these circuits could be built with "conventional" components, including "simple CMOS switches and sample-and-hold capacitors and integrated with low-frequency differential amplifiers." Petitioner argued that a POSITA would look to Enz for a conventional switched-capacitor sample-and-hold circuit (disclosing a switch and capacitor) to implement Lam's two down-conversion modules. A POSITA would then look to Tayloe for a standard differential amplifier to serve as the subtractor module that Lam's architecture required. Lam also explicitly taught "under-sampling" at a frequency "substantially lower than the carrier frequency," directly meeting the limitation in claim 2. For dependent claim 4, Petitioner asserted that the switched-capacitor circuit in Enz was known to inherently perform DC-offset reduction, thus teaching the final limitation.
  • Motivation to Combine: A POSITA would combine these references because Lam provided a high-level design for a down-converting receiver and expressly directed a skilled artisan to use well-known, conventional components to build it. Enz and Tayloe provided exemplary disclosures of precisely those conventional components—a sample-and-hold circuit and a differential amplifier, respectively—used for their intended and known functions.
  • Expectation of Success: The combination would yield predictable results because it involved implementing a system (Lam) with standard, off-the-shelf circuit building blocks (Enz and Tayloe) that were known to be suitable for such applications.

4. Key Claim Construction Positions

• "frequency down-conversion module" (Claim 2): Petitioner argued this term should be construed under 35 U.S.C. §112(6) (pre-AIA) as a means-plus-function limitation. The claimed function was identified as "to down-convert the input signal...according to a...control signal and output...a down-converted signal." The corresponding structure disclosed in the ’444 patent was an "aliasing module" comprising at least one switch and one capacitor.
• "subtractor module" (Claims 2, 3): Petitioner also argued this term should be construed as a means-plus-function limitation. The claimed function was "to subtract[] said second down-converted signal from said first...and output[] a down-converted signal." The corresponding structure in the ’444 patent was identified as a differential amplifier.
• "under-samples" (Claim 2): Petitioner adopted the district court's construction of this term to mean "sampling at less than or equal to twice the frequency of the input signal."

5. Arguments Regarding Discretionary Denial

• Petitioner filed a concurrent motion to join this proceeding with IPR2021-00990 ("the TCL IPR"), which challenged the same claims on substantially identical grounds. Petitioner argued that since the Board had already instituted the TCL IPR, declining to exercise discretionary denial under §325(d) (prior art previously considered by the USPTO) and the Fintiv factors, it should do the same here for similar reasons. Petitioner noted that a Final Written Decision in the TCL IPR was expected well before the trial date in the parallel district court litigation, weighing against discretionary denial.

6. Relief Requested

• Petitioner requested institution of an inter partes review and cancellation of claims 2, 3, and 4 of the ’444 patent as unpatentable.