PTAB

IPR2020-01265

Intel Corp v. ParkerVision Inc

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Method and System for Frequency Down-Conversion
  • Brief Description: The ’444 patent discloses a wireless modem apparatus for performing radio frequency (RF) down-conversion. The system uses two frequency down-conversion modules and a subtractor module to convert a high-frequency input signal into a low-frequency baseband signal for processing.

3. Grounds for Unpatentability

Ground 1: Claims 1, 3, and 5 are obvious over Tayloe in view of TI Datasheet.

  • Prior Art Relied Upon: Tayloe (Patent 6,230,000) and TI Datasheet (SN74CBT3253D Dual 1-of-4 FET Multiplexer/Demultiplexer, rev. ed. May 1998).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Tayloe, a patent for a direct conversion receiver, discloses all key elements of the challenged claims. Tayloe’s receiver includes two frequency down-conversion modules (its 0° and 180° modules) that each use a switch and a storage element (capacitor) to sample an RF input signal. Tayloe also discloses a subtractor module (its “summing amplifier” 50) that differentially sums the outputs of the two down-conversion modules. Crucially, Petitioner asserted that Tayloe discloses the two limitations added during prosecution to overcome prior art: (1) a timing delay between control signals, showing a 0.5-cycle (180°) phase shift between the control signals for the 0° and 180° modules, which is functionally identical to the claimed "(0.5+n) cycles" delay; and (2) the use of a switch and storage element (capacitor) in each down-conversion module. The TI Datasheet provides the specific implementation details for the multiplexer/demultiplexer switch that Tayloe’s specification expressly identifies as a suitable component. Dependent claim 5, which requires the subtractor module to comprise a differential amplifier, was also allegedly disclosed by Tayloe’s summing amplifier 50.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine Tayloe with the TI Datasheet because Tayloe explicitly discloses and recommends using the specific Texas Instruments multiplexer/demultiplexer described in the TI Datasheet to implement its commutating switch. This express reference provides a direct and compelling motivation for the combination.
    • Expectation of Success: A POSITA would have a high expectation of success, as the combination involves implementing a circuit (Tayloe) with a commercially available component (the TI multiplexer) that Tayloe itself identifies for this exact purpose, leading to predictable results.

Ground 2: Claims 1, 3, and 5 are obvious over Tayloe in view of Kawada.

  • Prior Art Relied Upon: Tayloe (Patent 6,230,000) and Kawada (Patent 4,985,647).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground was presented as an alternative to Ground 1. Petitioner argued that Kawada, like the TI Datasheet, discloses a conventional multiplexer/demultiplexer with the same fundamental switch configuration. The combination of Tayloe and Kawada allegedly teaches the same claim elements as the Tayloe/TI Datasheet combination. Tayloe provides the overall architecture and key features, while Kawada provides the well-understood structure of a suitable multiplexer/demultiplexer switch that could be used to implement Tayloe’s switch 38.
    • Motivation to Combine: A POSITA would combine Tayloe with Kawada because Tayloe discloses using a generic multiplexer/demultiplexer, and Kawada describes a standard, conventional design for such a component that was well-known at the time. A POSITA would have been motivated to look to known components like that in Kawada to implement Tayloe's switch to achieve predictable performance.
    • Expectation of Success: The combination represents the simple substitution of one known element (Tayloe’s generic switch) for another known element (Kawada’s conventional multiplexer) to obtain predictable results, giving a POSITA a reasonable expectation of success.

4. Key Claim Construction Positions

  • “frequency down-conversion module” and “subtractor module” (Claims 1, 3): Petitioner argued these terms should be construed as means-plus-function limitations under 35 U.S.C. §112, para. 6. Petitioner contended that the word "module" is a well-known nonce word that fails to recite sufficiently definite structure for performing the claimed functions.
    • Claimed Function (down-conversion module): "to down-convert the input signal ... according to a [] control signal and output[] a [] down-converted signal."
    • Corresponding Structure: The "aliasing module 2000" shown in the ’444 patent’s Figures 20A and 20A-1, which includes a switch in series with an input signal and a capacitor shunted to ground.
    • Claimed Function (subtractor module): "[to] subtract[] said second down-converted signal from said first down-converted signal and output[] a down-converted signal."
    • Corresponding Structure: The differential amplifier 7020 shown in Figure 70A of the ’444 patent.

5. Arguments Regarding Discretionary Denial

  • Discretionary Denial under §325(d): Petitioner argued that denial would be improper because the Examiner committed a material error during prosecution. Although Tayloe was cited in an Information Disclosure Statement (IDS), it was one of over 900 references submitted and there is no evidence the Examiner substantively considered it. Petitioner asserted this oversight was a material error because Tayloe explicitly discloses the very limitations—the control signal delay and the switch/storage element structure—that the Examiner relied upon to allow the challenged claims.
  • Discretionary Denial under §314(a) (Fintiv Factors): Petitioner argued against discretionary denial based on parallel district court litigation, contending that: (1) the petition was filed promptly (five months after litigation began); (2) the court case was in a very early stage, with fact discovery stayed and a trial date set for February 2022, nearly 18 months away; (3) there would be no duplication of effort as the IPR challenges different claims than those asserted in the litigation; and (4) the petition presented strong merits for invalidity.

6. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 1, 3, and 5 of the ’444 patent as unpatentable under 35 U.S.C. §103.