Texas Instruments Inc v. ParkerVision Inc

1. Case Identification

• Case #: IPR2024-00934
• Patent #: 7,496,342
• Filed: May 18, 2024
• Petitioner(s): Texas Instruments Incorporated
• Patent Owner(s): ParkerVision, Inc.
• Challenged Claims: 18-23

2. Patent Overview

• Title: Down-Converting Electromagnetic Signals, Including Controlled Discharge of Capacitors
• Brief Description: The ’342 patent relates to a method for down-converting an electromagnetic signal using a differential circuit architecture. The method involves controlling charging and discharging cycles of first and second capacitors via respective switching devices to generate down-converted signals across impedance devices.

3. Grounds for Unpatentability

Ground 1A: Obviousness over DeMaw - Claims 18-21 and 23 are obvious over DeMaw.

• Prior Art Relied Upon: DeMaw (Practical RF Design Manual, Prentice-Hall 1982).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that DeMaw, a well-known RF design manual, discloses a dual field-effect transistor (FET) balanced mixer circuit (Fig. 6.7) that performs all steps of independent claim 18. Petitioner asserted that DeMaw’s circuit receives an RF information signal, uses a 180° hybrid coupler to create an inverted version, and controls FETs (acting as switches) with a local oscillator signal to alternately couple these signals to capacitors. This process controls the charging and discharging cycles of the capacitors to generate down-converted signals across impedance devices. To substantiate this, Petitioner provided detailed SPICE simulations of the DeMaw circuit, arguing the results demonstrate that the circuit inherently performs the claimed method steps and even satisfies the specific capacitor discharge percentage ranges recited in dependent claims 19-21 and the carrier removal required by claim 23.
  • Motivation to Combine (for §103 grounds): Not applicable as this is a single-reference ground.
  • Expectation of Success (for §103 grounds): Not applicable as this is a single-reference ground.

Ground 1B: Obviousness over DeMaw and Tayloe - Claims 22-23 are obvious over the combination of DeMaw and Tayloe.

• Prior Art Relied Upon: DeMaw (Practical RF Design Manual, Prentice-Hall 1982) and Tayloe (Patent 6,230,000).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner contended that DeMaw’s balanced mixer produces down-converted signals at an intermediate frequency (IF). Tayloe discloses a direct conversion receiver for converting an RF or IF signal to baseband, which includes summing amplifiers (claim 22) that amplify the down-converted signals. The combination of DeMaw’s mixer outputting an IF signal and Tayloe’s circuitry receiving that IF signal for further down-conversion and amplification would render claim 22 obvious. Petitioner argued Tayloe’s direct-conversion process inherently removes the carrier signal, also teaching claim 23.
  • Motivation to Combine (for §103 grounds): A POSITA would combine DeMaw with Tayloe to create a complete superheterodyne receiver. DeMaw provides the initial mixing stage to produce an IF signal, and a POSITA would have sought known circuitry to further down-convert this IF signal to baseband. Tayloe was asserted to be an ideal choice because its circuitry is explicitly described as suitable for the last stage of a superheterodyne receiver, is configured to receive a single-ended IF input like that produced by DeMaw, and offers known benefits such as lower conversion loss.
  • Expectation of Success (for §103 grounds): Petitioner asserted a POSITA would have an expectation of success because both DeMaw and Tayloe teach well-understood RF circuit principles, and Tayloe provides experimental results confirming its functionality.

Ground 2: Obviousness over Macnally - Claims 18-23 are obvious over Macnally.

• Prior Art Relied Upon: Macnally (WO 00/16492).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Macnally discloses a single-chip CMOS direct-conversion transceiver that teaches all challenged claims. Macnally’s receiver was shown to receive an RF signal at an antenna interface, use off-chip components to create a differential (and thus inverted) signal, and feed it to a mixer. The mixer’s LO input transistors operate as switches (M5, M8), controlled by a local oscillator, to steer current and thereby electrically couple the information signals to capacitors in a subsequent anti-aliasing filter. Petitioner asserted this performs the claimed charging and discharging cycles to generate down-converted signals across impedance devices (resistors) in the filter. The anti-aliasing filter itself provides amplification (claim 22), and the direct-conversion architecture inherently removes the RF carrier (claim 23).
  • Motivation to Combine (for §103 grounds): Not applicable as this is a single-reference ground.
  • Expectation of Success (for §103 grounds): Not applicable as this is a single-reference ground.

4. Key Claim Construction Positions

• Petitioner argued that the prior art renders the challenged claims unpatentable under either its own or the Patent Owner’s proposed claim constructions from a co-pending litigation.
• "controlling a charging and discharging cycle": Petitioner proposed this means "controlling a cycle of charging and then discharging," implying a sequential order. Patent Owner argued the term does not impose a sequential order.
• "switching device": Petitioner proposed this is an electronic device that opens and closes an electrical path. Patent Owner argued the term requires "an independent control input." Petitioner asserted the prior art switches meet either construction.

5. Key Technical Contentions (Beyond Claim Construction)

• Petitioner relied heavily on detailed SPICE circuit simulations for both the DeMaw and Macnally references. This was presented as conclusive evidence that the prior art circuits, when operated as described, inherently perform the functional method steps of the challenged claims, including specific quantitative limitations in dependent claims. This addresses a stated deficiency in a previously denied IPR on the same patent.

6. Arguments Regarding Discretionary Denial

• §325(d) (Advanced Bionics): Petitioner argued against denial because the primary references, DeMaw and Macnally, were never presented to or considered by the USPTO during prosecution of the ’342 patent. Petitioner contended these references present a patentability challenge that is not the same as or substantially similar to those previously considered.
• §314(a) (Fintiv): To mitigate concerns related to co-pending district court litigation, Petitioner stated it has voluntarily presented a Sotera stipulation to the Patent Owner. This stipulation would prevent Petitioner from pursuing the same invalidity grounds in the district court, thereby eliminating the risk of duplicative efforts and weighing strongly in favor of institution.

7. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 18-23 of the ’342 patent as unpatentable.