PTAB

IPR2025-00325

Realtek Semiconductor Corp v. ParkerVision Inc

Log In
Key Events
Petition
petition Intelligence

1. Case Identification

2. Patent Overview

  • Title: METHOD AND SYSTEM FOR DOWN-CONVERTING AN ELECTROMAGNETIC SIGNAL, AND TRANSFORMS FOR SAME, AND APERTURE RELATIONSHIPS
  • Brief Description: The ’528 patent discloses a system for frequency down-converting a modulated radio frequency (RF) signal to in-phase (I) and quadrature (Q) baseband signals. The system utilizes parallel processing modules, each comprising switches and energy storage elements, to sample and integrate portions of the RF signal to generate the down-converted outputs.

3. Grounds for Unpatentability

Ground 1: Obviousness over Tayloe, TI Datasheet, and Macnally - Claims 1, 5, 8-9, 11-19, 23, 26-27, 29-36 are obvious over Tayloe in view of the TI Datasheet and Macnally.

  • Prior Art Relied Upon: Tayloe (Patent 6,230,000), TI Datasheet (for the SN74CBT3253 multiplexer/demultiplexer), and Macnally (Patent 7,065,327).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Tayloe disclosed the core architecture of a direct conversion receiver that meets the limitations of claim 1, including using a commutating switch to sample an RF signal into four phases (0, 90, 180, 270 degrees) and using capacitors to store/integrate the sampled energy. Petitioner asserted that Tayloe explicitly identified a Texas Instruments multiplexer (SN74BCT3253D) as a suitable implementation for its commutating switch. The TI Datasheet provided the detailed circuitry of this component, showing it comprises individual FET switches as claimed. Tayloe further taught combining the 0-degree and 180-degree outputs with a summing amplifier to produce a differential in-phase baseband signal. Macnally was argued to teach a fully differential amplifier with a low-pass filter, a well-known circuit for processing baseband signals in integrated circuit receivers.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine Tayloe and the TI Datasheet because Tayloe expressly referenced the specific TI part number, directly motivating a designer to consult its datasheet for implementation details. The motivation to incorporate Macnally’s fully differential amplifier into Tayloe's design stemmed from the known benefits of using such circuits in integrated receivers to improve performance, reduce noise, and decrease unit cost—goals explicitly mentioned by Macnally. A POSITA would substitute Tayloe's generic summing amplifier with Macnally's superior, well-understood differential amplifier circuit to achieve these predictable benefits.
    • Expectation of Success: A POSITA would have a high expectation of success because the combination involved implementing a disclosed component (Tayloe's switch) with its corresponding datasheet (TI Datasheet) and replacing another component (Tayloe's amplifier) with a known, improved version (Macnally's amplifier) to achieve predictable performance enhancements.

Ground 2: Obviousness over Razavi and Macnally - Claims 1, 5, 8-9, 11-19, 23, 26-28, 30-36 are obvious over Razavi in view of Macnally.

  • Prior Art Relied Upon: Razavi (a 1997 IEEE journal article, "A 900-MHz CMOS Direct Conversion Receiver") and Macnally (Patent 7,065,327).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner contended that Razavi disclosed a direct conversion CMOS receiver with I and Q mixers that met the key limitations of claim 1. Razavi’s mixers used pairs of alternately-switched transistors (e.g., M5 and M6) to sample an RF signal, with capacitors (Cp and Cm) storing the transferred energy to produce down-converted, differential in-phase and inverted in-phase baseband signals. Razavi explicitly stated that its design required, but did not detail, "channel-selection filtering" at the baseband. Macnally provided the exact type of circuit a POSITA would use for this purpose: a fully differential amplifier configured as a low-pass (anti-aliasing) filter, which is ideal for processing mixer outputs in an integrated circuit.
    • Motivation to Combine: A POSITA, reading Razavi's disclosure of a receiver that requires baseband filtering, would be motivated to look for well-known filter circuits to complete the design. Macnally provided a suitable, high-performance, fully differential, low-pass filter circuit specifically designed for integrated communication systems. The combination was presented as a straightforward implementation of a necessary functional block (filtering) into a receiver architecture that explicitly called for it.
    • Expectation of Success: There would be a reasonable expectation of success because applying a known filter circuit (Macnally) to the output of a mixer (Razavi) is a standard design step in receiver architecture. The combination represented the pairing of complementary, well-understood circuit blocks to achieve a predictable, functional system.
  • Additional Grounds: Petitioner asserted additional obviousness challenges (Grounds 1B and 2B) based on the combinations above further in view of Cahn (a 1960 journal article). Cahn was relied upon to teach various modulation techniques (amplitude, phase, and combined), rendering it obvious to apply the primary combinations to signals with such modulations as recited in dependent claims 2-4 and 20-22.

4. Key Claim Construction Positions

  • Petitioner argued that the terms "storage element" and "energy storage element" should be construed to mean "an element of a system that stores non-negligible amounts of energy from an input EM signal."
  • This construction was asserted to be critical because it did not require the element to be part of a restrictive "energy transfer system" as the Patent Owner had previously argued. Petitioner supported this position by citing a prior Federal Circuit decision that affirmed this exact construction for a related patent (incorporated by reference into the ’528 patent) where the patentee had acted as its own lexicographer.

5. Arguments Regarding Discretionary Denial

  • Petitioner argued that discretionary denial would be improper.
  • Under §325(d) (Advanced Bionics), Petitioner asserted that none of the cited prior art or arguments were substantively considered by the USPTO during prosecution of the ’528 patent.
  • For General Plastic factors, Petitioner noted it had filed a motion for joinder to an existing IPR, which it argued neutralizes concerns about parallel proceedings.
  • Regarding the Fintiv factors, Petitioner stated it had eliminated any risk of duplicative effort by voluntarily presenting a Sotera stipulation to the Patent Owner, which pledges not to pursue the same invalidity grounds in district court.

6. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 1-5, 8-9, 11-23, 26-27, and 29-36 of the ’528 patent as unpatentable under 35 U.S.C. §103.