PTAB

IPR2025-00324

Realtek Semiconductor Corp v. ParkerVision Inc

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Petition
petition Intelligence

1. Case Identification

2. Patent Overview

  • Title: Method and System for Down-Converting an Electromagnetic Signal
  • Brief Description: The ’177 patent discloses a method for down-converting an electromagnetic signal using first and second "matched filtering/correlating modules." Each module independently down-converts an input signal, and the resulting first and second down-converted signals are then combined.

3. Grounds for Unpatentability

Ground 1: Obviousness over Tayloe and TI Datasheet - Claim 14 is obvious over Tayloe in view of the TI Datasheet.

  • Prior Art Relied Upon: Tayloe (Patent 6,230,000) and TI SN74CBT3253 Datasheet (TI Datasheet).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Tayloe disclosed a direct conversion receiver that met all limitations of claim 14. Tayloe’s circuit used a commutating switch to sample a radio frequency (RF) input signal at four phases (0, 90, 180, 270 degrees), integrate the samples on corresponding capacitors, and combine them to produce baseband in-phase (I) and quadrature (Q) signals. Petitioner identified the circuitry processing the 0/180 degree signals as the first matched filtering/correlating module and the circuitry processing the 90/270 degree signals as the second module. The TI Datasheet provided specifics for the Texas Instruments multiplexer/demultiplexer that Tayloe expressly identified for use as its commutating switch.
    • Motivation to Combine: Petitioner contended a POSITA would combine the references because Tayloe explicitly disclosed using the specific Texas Instruments component described in the TI Datasheet. Consulting the datasheet for a named component was argued to be a standard and obvious step for a POSITA implementing the circuit. The combination would yield predictable results, such as low on-state resistance and minimal propagation delay, as described in the TI Datasheet.
    • Expectation of Success: A POSITA would have a high expectation of success because Tayloe directed the use of the component detailed in the TI Datasheet, making the combination a straightforward implementation of Tayloe’s own teaching.

Ground 2A: Obviousness over Razavi - Claim 14 is obvious over Razavi.

  • Prior Art Relied Upon: Razavi (a 1997 IEEE Symposium article on a 900-MHz CMOS Direct Conversion Receiver).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Razavi alone rendered claim 14 obvious under the Patent Owner’s proposed claim construction. Razavi described a direct conversion receiver architecture with quadrature mixers for down-converting a 900 MHz RF signal to baseband. Petitioner mapped the in-phase (I) mixer circuit to the ’177 patent’s first matched filtering/correlating module and the quadrature (Q) mixer to the second module. Each Razavi mixer comprised switches (transistors M5/M6), a capacitor, and a load, which Petitioner argued satisfied the structural requirements of a matched filtering/correlating module. The mixers produced separate down-converted I and Q signals that were further processed by a baseband amplifier, which inherently combined them.

Ground 2B: Obviousness over Razavi and Uzunoglu - Claim 14 is obvious over Razavi in view of Uzunoglu.

  • Prior Art Relied Upon: Razavi (1997 IEEE Symposium article) and Uzunoglu (a 1985 IEEE Journal article on synchronous oscillators).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground argued that the combination of Razavi and Uzunoglu rendered claim 14 obvious under a plain-and-ordinary meaning construction of "matched filtering/correlating module." Razavi provided the core direct conversion receiver architecture, as in Ground 2A. Uzunoglu supplied the teaching of a synchronous oscillator (SO) circuit for carrier synchronization, a feature Petitioner argued was required by the plain meaning of "correlating" but was absent in Razavi. Uzunoglu’s SO synchronized a local oscillator’s output with the frequency and phase of an incoming RF signal's carrier.
    • Motivation to Combine: A POSITA would combine Razavi's receiver with Uzunoglu's synchronization circuit to solve a known problem. Independent oscillators in a transmitter and receiver (like Razavi’s) inevitably have slight frequency deviations, requiring additional processing to correct. A POSITA would be motivated to use a carrier synchronization circuit like Uzunoglu's to synchronize Razavi’s local oscillator with the received signal’s carrier, thereby eliminating this frequency deviation, simplifying subsequent processing, and enabling synchronous demodulation.
    • Expectation of Success: A POSITA would have a reasonable expectation of success, as Uzunoglu provided detailed implementation guidance for its SO circuit and explained its desirable properties, such as extracting signals with low carrier-to-noise ratios. This was a well-known technique for improving receiver performance.

4. Key Claim Construction Positions

  • Petitioner argued claim 14 was unpatentable under two alternative constructions for the key term "matched filtering/correlating module":
    • Patent Owner’s Proposed Construction: Based on a pending litigation, this construction defined the module as complex "linear time-variant circuitry" with numerous specific functional limitations, including sampling at an aliasing rate, accumulating energy in a load while a switch is closed, and discharging through the load while the switch is open. Petitioner mapped the prior art to this detailed construction in Grounds 1 and 2A.
    • Plain-and-Ordinary Meaning: Petitioner argued this term’s plain meaning, in light of the ’177 patent’s specification, required correlating a control signal (for sampling) with the input signal's carrier frequency to achieve synchronicity. Petitioner contended this synchronization was essential for the enhanced signal-to-noise ratio described in the patent but was absent from the Patent Owner’s construction. This construction was applied in Ground 2B.

5. Arguments Regarding Discretionary Denial

  • §325(d) (Advanced Bionics): Petitioner argued against discretionary denial because the primary references (Tayloe, Razavi, Uzunoglu) were not substantively considered by the examiner during prosecution. Although Tayloe and articles by Razavi were cited on the face of the patent, Petitioner asserted there was no evidence the examiner appreciated their teachings as applied in the petition, making the challenges new and non-cumulative.
  • §314(a) (Fintiv): To mitigate concerns related to parallel district court litigation under the Fintiv factors, Petitioner stated it had voluntarily presented a Sotera stipulation to the Patent Owner. This stipulation promised not to pursue the same grounds or any grounds that could have reasonably been raised in the IPR in the parallel litigation, which Petitioner argued eliminated the risk of duplicative efforts and weighed strongly against denial.

6. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claim 14 of the ’177 patent as unpatentable under 35 U.S.C. §103.