NXP USA Inc v. ParkerVision Inc

1. Case Identification

• Case #: IPR2024-01068
• Patent #: 9,118,528
• Filed: June 20, 2024
• Petitioner(s): NXP USA, Inc.
• Patent Owner(s): ParkerVision, Inc.
• Challenged Claims: 1-5, 8-9, 11-23, 26-27, 29-36

2. Patent Overview

• Title: System for Frequency Down-Converting a Modulated Carrier Signal
• Brief Description: The ’528 patent relates to a system for down-converting an I/Q modulated radio frequency (RF) signal to a baseband signal. The technology utilizes a receiver architecture with distinct processing modules for in-phase (I) and quadrature-phase (Q) signal components, each employing switches and energy storage elements to sample and integrate portions of the input signal.

3. Grounds for Unpatentability

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

• Prior Art Relied Upon: Tayloe (Patent 6,230,000), TI Datasheet (SN74CBT3253 Dual 1-of-4 FET Multiplexer/Demultiplexer Datasheet), and Macnally (Patent 7,065,327).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Tayloe disclosed a direct conversion receiver that met the core limitations of claim 1. Tayloe’s receiver used a "commutating switch" to sample an RF waveform at four phases (0, 90, 180, and 270 degrees) and integrated these samples on separate capacitors to produce average voltages. Petitioner mapped the 0-degree path to the claimed "first switch" and "first energy storage element" producing an in-phase signal, and the 180-degree path to the "second switch" and "second energy storage element" producing an inverted in-phase signal. Tayloe expressly taught implementing its switch with a Texas Instruments multiplexer, whose specific structure and operation were detailed in the TI Datasheet. Finally, Tayloe’s summing amplifiers, which combine the 0- and 180-degree outputs, were argued to be rendered obvious by Macnally’s disclosure of a fully differential amplifier and low-pass filter circuit commonly used in integrated transceivers.
  • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine Tayloe and the TI Datasheet because Tayloe explicitly identified the specific component described in the datasheet. A POSITA would have been motivated to implement Tayloe’s summing amplifier with Macnally’s fully differential amplifier to achieve the well-known benefits of improved linearity, noise immunity, and reduced cost by enabling a single-chip integrated circuit design, a primary goal in the field.
  • Expectation of Success: The combination would have yielded predictable results. It involved using a commercially available component (the TI multiplexer) as expressly suggested by Tayloe and substituting a well-understood circuit block (Macnally's differential amplifier) for a generic one (Tayloe's summing amplifier) to achieve known performance improvements.

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

• Prior Art Relied Upon: Razavi (A 900-MHz CMOS Direct Conversion Receiver, 1997 IEEE Symposium) and Macnally (Patent 7,065,327).

• Core Argument for this Ground:

  • Prior Art Mapping: Petitioner contended that Razavi disclosed a direct conversion receiver architecture that anticipated the key features of the challenged claims. Razavi’s in-phase (I) mixer was shown to include a pair of switches (transistors M5 and M6) controlled by complementary signals. These switches alternately connected the input signal to two separate capacitors (Cp and Cm), which function as energy storage elements. Petitioner argued this arrangement directly mapped to the claimed first and second switches and first and second energy storage elements, producing complementary down-converted in-phase and inverted in-phase baseband signals. Razavi acknowledged the need for channel-selection filtering and amplification but did not detail the circuitry. Macnally provided this missing detail, disclosing a suitable fully differential, low-pass filter and amplifier circuit for processing mixer outputs in an integrated transceiver.
  • Motivation to Combine: A POSITA would combine Razavi and Macnally to complete Razavi's design. Razavi identified the need for a low-pass filter and baseband amplifier for channel selection, and Macnally provided a detailed, well-known circuit implementation for that exact purpose. The combination represented a straightforward implementation of a conceptual block in Razavi's system with a standard circuit from Macnally to create a complete, functional receiver.
  • Expectation of Success: A POSITA would have had a high expectation of success because combining the references involved adding a known functional block (Macnally's filter/amplifier) to a receiver design (Razavi) that explicitly required it, a common practice in integrated circuit design.

• Additional Grounds: Petitioner asserted further obviousness challenges (Grounds 1B and 2B) against claims 2-4 and 20-22. These grounds added Cahn (a 1960 article on modulation) to the primary combinations to explicitly teach applying amplitude, phase, or combined modulation to the carrier signal, which the combination systems would be capable of down-converting.

4. Key Claim Construction Positions

• Petitioner argued for the construction of "storage element" or "energy storage element" as "an element of a system that stores non-negligible amounts of energy from an input EM signal."
• This proposed construction was based on a prior Federal Circuit decision that affirmed the Board’s construction in another case involving the Patent Owner. Petitioner contended that this construction was based on express lexicography from a patent incorporated by reference into the ’528 patent and that the prior art capacitors (e.g., in Tayloe and Razavi), when coupled to a low-impedance load provided by the subsequent amplifier stage (Macnally), met this definition.

5. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under §325(d) would be inappropriate because the prior art references asserted in the petition (Tayloe, TI Datasheet, Macnally, Razavi, Cahn) were not previously applied by the Examiner during the prosecution of the ’528 patent.
• Petitioner further contended that denial under Fintiv was unwarranted because it had provided the Patent Owner with a Sotera stipulation, agreeing not to pursue the same invalidity grounds or any that could have reasonably been raised in the IPR in the co-pending district court litigation, thereby mitigating concerns of duplicative efforts.

6. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1-5, 8-9, 11-23, 26-27, and 29-36 of the ’528 patent as unpatentable.