MediaTek Inc v. ParkerVision Inc

1. Case Identification

• Case #: IPR2024-00150
• Patent #: 7,292,835
• Filed: November 15, 2023
• Petitioner(s): MediaTek Inc.
• Patent Owner(s): ParkerVision, Inc.
• Challenged Claims: 1-5

2. Patent Overview

• Title: Receivers for Cable Modem Applications
• Brief Description: The ’835 patent relates to a Quadrature Amplitude Modulation (QAM) receiver, purportedly for cable modems, used to down-convert and demodulate an input electromagnetic signal. The receiver uses two frequency down-conversion modules to process in-phase (I) and quadrature-phase (Q) components of the signal.

3. Grounds for Unpatentability

Ground 1: Claims 1-5 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 argued that Gibson disclosed the overall architecture of a quadrature receiver modem for down-converting an electromagnetic signal, including an oscillator, a phase shifter, and two down-conversion modules (mixers) for the I and Q signal paths. However, Gibson did not detail the internal structure of its mixers. Schiltz allegedly supplied this missing detail by teaching a "high speed sample and hold circuit," comprising a switch (FET) and a "hold capacitor," explicitly for use "as a mixer" in down-conversion applications. Petitioner contended that substituting Schiltz's sample-and-hold mixer for each of the generic mixers in Gibson's architecture would result in the configuration claimed in the ’835 patent. The switch in Schiltz was argued to be the claimed "frequency translation module" and the capacitor was the claimed "storage module."
  • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine the references because Gibson required mixers for its receiver, and Schiltz expressly taught using its sample-and-hold circuit for this exact purpose in radio applications. Schiltz promoted its circuit for its ability to operate accurately at high frequencies, providing a clear benefit for its integration into Gibson's modem. The combination was presented as a simple substitution of a known, improved component (Schiltz's mixer) into a conventional system (Gibson's receiver).
  • Expectation of Success: A POSITA would have had a high expectation of success because combining the references involved using known circuit elements for their intended and understood purposes, which would yield only predictable results.

Ground 2: Claims 1-5 are obvious over Crols

• Prior Art Relied Upon: Crols (J. Crols, A Single-Chip 900 MHz CMOS Receiver Front-End..., IEEE JOURNAL OF SOLID STATE CIRCUITS (Dec. 1995)).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner asserted that Crols, a single reference, disclosed all elements of the challenged claims. Crols’s Figure 12(b) showed a conventional quadrature downconverter architecture with I and Q mixers, a local oscillator (LO), and a quadrature generator (phase shifter). Crols’s Figure 17 separately disclosed a "highly linear mixer topology" comprising a CMOS transistor (switch) coupled to a capacitor. Petitioner argued Crols rendered the claims obvious on its own, but to the extent combination was needed, it would have been obvious to implement the specific mixer of Figure 17 into the conventional downconverter architecture of Figure 12(b). This combination allegedly met all limitations of claim 1, with the transistor serving as the "frequency translation module" and the capacitor as the "storage module."
  • Motivation to Combine: While Crols introduced a new, more complex downconverter, it also described the conventional architecture of Figure 12(b) as the "preferred topology" and widely used in mobile wireless applications. A POSITA would be motivated to use Crols’s high-performance mixer from Figure 17 within the well-known, cost-effective, and preferred conventional architecture of Figure 12(b). This would achieve the benefits of the improved mixer without the increased size, cost, and complexity of Crols's new four-mixer design.
  • Expectation of Success: Success was expected because Crols disclosed both the mixer and the downconverter topology as functional and compatible components for RF signal processing, making their combination a straightforward and predictable design choice.

4. Key Claim Construction Positions

• "cable modem" (Preamble): Petitioner argued that if the Board finds this preamble term limiting, it should be construed broadly to mean any modem that can down-convert modulated signals from a TV network. This construction would not be limited to devices that are wired or compliant with a specific standard (e.g., DOCSIS), thereby encompassing the general-purpose modem architectures disclosed in the prior art.
• "storage module": Petitioner urged the Board to adopt its construction from a prior IPR involving a related patent: "a module of a system that stores non-negligible amounts of energy from an input EM signal." This construction was argued to be consistent with the patent's lexicography and would prevent the Patent Owner from improperly importing functional limitations (e.g., "for driving a low impedance load") that were rejected in prior litigations.

5. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under Fintiv would be inappropriate. The parallel district court litigation was in a very early stage, with fact discovery stayed pending a Markman hearing, meaning minimal resources had been invested by the parties or the court. Petitioner asserted it filed the IPR expeditiously.
• Crucially, Petitioner contended the merits were compelling, noting the Board had already found claim 1 unpatentable over the same Gibson and Schiltz combination in a previous IPR (IPR2021-00985).
• Petitioner also argued against denial under §325(d), emphasizing that the primary prior art references (Gibson, Schiltz, and Crols) were never considered or analyzed by the examiner during the original prosecution of the ’835 patent.

6. Relief Requested

• Petitioner requested the institution of an inter partes review and the cancellation of claims 1-5 of the ’835 patent as unpatentable.