PTAB

IPR2018-01152

Intel Corp v. Qualcomm Inc

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Apparatus for Generating a Power Supply Signal for a Power Amplifier
  • Brief Description: The ’558 patent discloses techniques for efficiently generating a power supply for a radio frequency (RF) power amplifier. The technology centers on a hybrid supply generator that combines a high-efficiency switcher with a high-bandwidth envelope amplifier to achieve improved overall performance in wireless communication devices.

3. Grounds for Unpatentability

Ground 1: Anticipation of Claims 12 and 14

  • Legal Basis: Claims 12 and 14 are anticipated under 35 U.S.C. §102 by Chu.
  • Prior Art Relied Upon: Chu (W.Y. et al., “A 10 MHz Bandwidth, 2 mV Ripple PA Regulator for CDMA Transmitters,” IEEE Journal of Solid-State Circuits (2008)).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Chu, which was not before the Examiner during prosecution, discloses every element of independent claim 12. Chu describes a hybrid supply generator with a master-slave architecture that includes a switcher (switch-mode regulator) and an envelope amplifier (linear amplifier) that cooperate to provide a supply current to a power amplifier. Critically, Petitioner asserted that Chu also discloses the specific internal components—an operational amplifier, driver, PMOS transistor, and NMOS transistor—that the applicant added to overcome a rejection during prosecution. For dependent claim 14, Petitioner contended that Chu’s disclosure of the switcher dominating at low frequencies and the linear amplifier taking over at high frequencies inherently teaches the claimed frequency splitting.

Ground 2: Obviousness of Claim 14

  • Legal Basis: Claim 14 is obvious under 35 U.S.C. §103 over Chu in view of Blanken.
  • Prior Art Relied Upon: Chu (as cited above) and Blanken (P.G. et al., “A 50MHz Bandwidth Multi-Mode PA Supply Modulator for GSM, EDGE and UMTS Application,” 2008 Radio Frequency Integrated Circuits Symposium (IEEE)).
  • Core Argument for this Ground:
    • Prior Art Mapping: In the alternative to anticipation, Petitioner argued that if Chu was found not to explicitly disclose the frequency splitting of claim 14, Blanken provides the missing teaching. Blanken expressly describes a similar hybrid supply modulator where "the DC/DC converter [switcher] supplies the DC and low-frequency part of the load current, and the linear regulator [envelope amplifier] supplies the high-frequency part."
    • Motivation to Combine: A person of ordinary skill in the art (POSITA) would combine Blanken's explicit frequency-splitting technique with Chu's hybrid supply generator. Both references are from the same field, address the identical problem of balancing amplifier efficiency and bandwidth, and disclose similar master-slave architectures. Applying Blanken’s clear, advantageous technique to optimize Chu’s system would have been a logical design choice.
    • Expectation of Success: The combination would yield predictable results, as it involved applying a known optimization technique (Blanken's frequency splitting) to a known, similar device (Chu's generator) to achieve the well-understood benefit of improved efficiency.

Ground 3: Obviousness of Claim 13

  • Legal Basis: Claim 13 is obvious under §103 over Chu in view of Choi 2010.

  • Prior Art Relied Upon: Chu (as cited above) and Choi 2010 (J. et al., “Envelope Tracking Power Amplifier Robust to Battery Depletion,” Microwave Symposium Digest (MTT), 2010 IEEE MTT-S International).

  • Core Argument for this Ground:

    • Prior Art Mapping: Claim 13 adds a boost converter to the apparatus of claim 12. Petitioner argued that while Chu teaches the base combination of claim 12, Choi 2010 explicitly discloses a hybrid supply modulator that integrates a boost converter with the envelope amplifier. The stated purpose in Choi 2010 is to provide a stable, boosted supply voltage to prevent performance degradation and distortion as the device's battery depletes.
    • Motivation to Combine: A POSITA would have been motivated to incorporate Choi 2010’s boost converter into Chu’s design to solve the well-known problem of maintaining performance with a falling battery voltage. Choi 2010 even cites a related paper by Chu, indicating the technologies are directly compatible and that Choi 2010 represents a known improvement upon the same technological foundation.
    • Expectation of Success: A POSITA would have had a high expectation of success. Using a boost converter to provide a stable voltage to an amplifier was a standard technique in power electronics, and Choi 2010 demonstrates its successful application in a highly analogous hybrid circuit, confirming its predictable benefits.

  • Additional Grounds: Petitioner asserted an additional obviousness challenge for claim 13 based on the combination of Chu, Choi 2010, and Myers (Patent 5,929,702), arguing that Myers taught the selective use of either the battery voltage or the boosted voltage to further improve efficiency and preserve battery life.

4. Key Claim Construction Positions

  • "current sense amplifier" (claim 12): Petitioner adopted the construction from a parallel International Trade Commission (ITC) litigation: "amplifier that produces a voltage from a current." Petitioner argued this construction is consistent with the specification, whereas the Patent Owner's alternative proposal improperly imported a limitation that the amplifier "senses changes in current."
  • "envelope signal" (claim 12): Petitioner adopted the construction proposed by the Patent Owner in the ITC litigation: "signal indicative of the upper bound of the output RF signal." Petitioner presented this as a reasonable construction that was slightly narrower than other alternatives and thus favorable to the Patent Owner for the purposes of the invalidity analysis.

5. Key Technical Contentions (Beyond Claim Construction)

  • Petitioner's central technical contention was that the ’558 patent is a combination of well-known components that yields only predictable results. It was strongly emphasized that the primary prior art reference, Chu, was not considered during prosecution and discloses the very circuit elements (e.g., operational amplifier, driver, specific PMOS/NMOS transistor configurations) that the applicant relied on to argue for the patentability of the claims over the previously cited art.

6. Relief Requested

  • Petitioner requests institution of IPR and cancellation of claims 12-14 of Patent 8,698,558 as unpatentable.