PTAB

IPR2021-00985

TCL Industries Holdings Co Ltd v. ParkerVision Inc

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Frequency Up-Conversion and Down-Conversion System
  • Brief Description: The ’835 patent is directed to a modem for down-converting a high-frequency electromagnetic signal with complex modulations (e.g., QAM) to a lower-frequency baseband signal. The claimed architecture uses parallel in-phase (I) and quadrature (Q) down-conversion paths, each comprising a frequency translation module and a storage module.

3. Grounds for Unpatentability

Ground 1: Obviousness over Hulkko and Gibson - Claims 1, 12, 15, and 17 are obvious over Hulkko in view of Gibson.

  • Prior Art Relied Upon: Hulkko (Patent 5,734,683) and Gibson (Patent 4,682,117).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Hulkko discloses the core architecture of the ’835 patent, including a modem with two frequency down-conversion modules for processing I/Q signals, a local oscillator, and a phase-shifter. Hulkko's down-conversion modules were asserted to be mixers that function as sample-and-hold circuits using a switched capacitor arrangement, thus teaching the claimed "frequency translation module" (a switch) and "storage module" (a capacitor). To the extent Hulkko's phase-shifting mechanism is not explicit, Gibson was introduced to teach a conventional 90-degree phase shifter used to generate quadrature signals from an oscillator for use in respective I/Q mixers.
    • Motivation to Combine: Petitioner contended a POSITA would combine Hulkko with Gibson to implement a well-understood method for generating the quadrature signals Hulkko requires. Hulkko taught using signals 90 degrees out of phase but did not detail the mechanism. Gibson disclosed a conventional and simple implementation using a 90-degree phase shifter for the same purpose—demodulating I/Q signals. This combination represented a choice from a finite number of predictable solutions for a known problem.
    • Expectation of Success: Combining a standard phase shifter from Gibson into the receiver architecture of Hulkko was argued to be a straightforward application of known design principles that would yield predictable results.

Ground 2: Obviousness over Gibson and Schiltz - Claims 1, 12-15, and 17-20 are obvious over Gibson in view of Schiltz.

  • Prior Art Relied Upon: Gibson (Patent 4,682,117) and Schiltz (Patent 5,339,459).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Gibson provides the primary I/Q receiver architecture, disclosing two frequency down-conversion modules (mixers), a local oscillator, and a 90-degree phase shifter. However, Gibson did not expressly disclose that its mixers comprised a switched capacitor arrangement. Schiltz was introduced to supply this teaching, as it described a "high speed sample and hold circuit" using a switched capacitor (a field effect transistor switch and a hold capacitor) that is explicitly taught for use "as a mixer" for down-conversion in radio applications.
    • Motivation to Combine: A POSITA would combine the teachings because Gibson disclosed a general receiver architecture without specifying the internal workings of its mixers. Schiltz provided a well-known, high-performance implementation of a mixer using a sample-and-hold circuit, which it expressly teaches is beneficial for down-conversion. Petitioner argued it would have been an obvious substitution to use the specific mixer design of Schiltz for the more generic mixers in Gibson to improve performance, a predictable design choice.
    • Expectation of Success: Implementing the sample-and-hold mixer from Schiltz into Gibson’s receiver architecture was presented as a combination of known elements for their intended purposes, which would have been understood by a POSITA to yield the predictable result of an operational I/Q down-converter.

4. Key Claim Construction Positions

  • “cable modem” (preamble): Petitioner argued that if this term is found to be limiting, it should be construed broadly as any modem capable of down-converting modulated signals from a TV network, whether wired or wireless and regardless of compliance with a specific standard (e.g., DOCSIS). This construction is based on the ’835 patent’s specification and is critical for applying prior art modems that are not explicitly labeled "cable modems."
  • “frequency translation module”: Petitioner contended this term should be construed as a "switch." This construction is based on the patent’s disclosure, which shows the module as a switch in its aliasing module figures (Figs. 20A, 20A-1), and is supported by the language of dependent claims 18-20, which further define the module as a switch with specific ports.
  • “storage module”: Petitioner argued this term should be construed as a "capacitor or an inductor." The corresponding structure in the specification is a capacitor, and the patent discloses an inductor as an alternative.

5. Arguments Regarding Discretionary Denial

  • Petitioner presented substantial arguments against discretionary denial under 35 U.S.C. §314(a) based on the Fintiv factors. The core argument was that an IPR would be more efficient than the parallel district court litigations. Petitioner asserted that the court cases were in very early stages, with discovery stayed and a trial date set for after the statutory deadline for a Final Written Decision (FWD). Furthermore, Petitioner argued that the merits of the petition were particularly strong and based on primary prior art references (Hulkko and Gibson) that the examiner did not consider during the original prosecution.

6. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 1, 12-15, and 17-20 of the ’835 patent as unpatentable.