PTAB

IPR2018-01340

Intel Corp v. Qualcomm Inc

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Apparatus and Method of Power Tracking for a Plurality of Radio Frequency Signals
  • Brief Description: The ’675 patent discloses a technique for optimizing power efficiency in a wireless transmitter. The system uses a single power amplifier and a single power tracking supply generator to simultaneously transmit multiple "carrier aggregated" radio frequency (RF) signals, aiming to reduce circuit complexity and power consumption compared to architectures using multiple transmitters.

3. Grounds for Unpatentability

Ground 1: Claims 31 and 32 are obvious over Yu in view of Wang and Choi.

  • Prior Art Relied Upon: Yu (European Application # EP 2 442 440 A1), Wang ("Design of Wide-Bandwidth Envelope-Tracking Power Amplifiers for OFDM Applications," 2005), and Choi ("Envelope Tracking Power Amplifier Robust to Battery Depletion," 2010).
  • Core Argument for this Ground: Petitioner asserted that the core inventive concept of the ’675 patent—using a single power amplifier and a single power tracking supply for multiple aggregated signals—was already disclosed by Yu. The remaining limitations in the challenged claims were argued to be well-known elements that a person of ordinary skill in the art (POSA) would have been motivated to add by combining the teachings of Wang and Choi. Specifically, Wang was cited for its disclosure of I/Q signal processing and Orthogonal Frequency Division Multiplexing (OFDM) in envelope tracking systems, while Choi was cited for its disclosure of a specific, efficient power supply generator architecture.
    • Prior Art Mapping: Petitioner argued that Yu discloses the fundamental architecture claimed in the ’675 patent, including a control unit (power tracker) and a power amplifier configured to amplify a combined RF signal derived from multiple input signals (S1, S2). Yu’s control unit generates a single control signal (CTRL) based on the inputs to dynamically adjust the power amplifier’s supply voltage, which is the essence of power tracking.
      • To meet limitations regarding in-phase (I) and quadrature (Q) components, which Yu does not explicitly detail, Petitioner contended a POSA would look to Wang. Wang taught an envelope-tracking power amplifier that expressly processes a "complex baseband signal" using its I and Q components to derive the signal’s amplitude. Wang also explicitly taught the use of OFDM signals in such a system.
      • To meet limitations related to the specific structure of the power supply generator (recited in means-plus-function limitations), Petitioner argued a POSA would implement Yu’s generic "supply voltage module" using the detailed hybrid switching amplifier (HSA) taught by Choi. Choi’s HSA, designed for envelope tracking, included a power tracking amplifier, a switcher (buck converter), and a boost converter, a structure Petitioner asserted is equivalent to the power supply generator disclosed in the ’675 patent.
    • Motivation to Combine: A POSA would combine Yu and Wang because both address envelope tracking for wide-bandwidth signals. As Yu describes a system for standards like UMTS and LTE which inherently use I/Q modulation, a POSA would naturally turn to a reference like Wang to implement the well-known and efficient I/Q and OFDM processing techniques. Similarly, a POSA implementing Yu's high-level architecture would be motivated to use Choi's specific power supply generator design to gain its known benefits of high efficiency and robustness against battery depletion, which are critical for mobile devices. All three references are from the same field and address complementary aspects of a single technical problem.
    • Expectation of Success: A POSA would have a reasonable expectation of success in combining these references. The integration involved applying known techniques (I/Q processing, OFDM modulation, HSA power supplies) to a known system (Yu's envelope tracker) for their conventional purposes. Petitioner argued such a combination would yield only predictable results.

4. Key Claim Construction Positions

Petitioner argued that the claims are obvious even under the constructions adopted by an administrative law judge (ALJ) in a parallel International Trade Commission (ITC) investigation. Key positions included:

  • "plurality of carrier aggregated transmit signals": Petitioner proceeded under the ALJ's construction of "signals for transmission on multiple carriers at the same time to increase the bandwidth for a user."
  • "power tracker": Petitioner adopted the ALJ’s construction of a “component in a voltage generator that computes the power requirement.”
  • "single power tracking signal": Petitioner adopted the ALJ’s construction of “one (single-ended) power tracking signal.”
  • Means-Plus-Function Terms: For several means-plus-function limitations (e.g., "means for determining a single power tracking signal"), Petitioner argued that the structures disclosed in the combination of Yu, Wang, and Choi were identical or, at a minimum, structurally equivalent to the corresponding structures (or lack thereof) described in the ’675 patent specification.

5. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 31 and 32 of the ’675 patent as unpatentable under 35 U.S.C. §103.