PTAB

IPR2018-01328

Intel Corp v. Qualcomm Inc

Log In
Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Apparatus and Method for Transmitting Multiple Signals Simultaneously with Power Tracking
  • Brief Description: The ’675 patent relates to a technique for efficiently transmitting multiple carrier-aggregated radio frequency (RF) signals simultaneously. The system uses a single power amplifier (PA) and a single power tracking supply generator, which purportedly reduces circuit complexity, cost, and power consumption compared to conventional architectures that required multiple transmitters.

3. Grounds for Unpatentability

Petitioner asserted four grounds for unpatentability under 35 U.S.C. §103, arguing that the challenged claims would have been obvious to a person of ordinary skill in the art (POSA). The primary reference, Chen, was argued to disclose the core concept of the patent, with secondary references supplying well-known implementation details.

Ground I: Claims 1-3, 5, 7, 11, 17-21, and 27 are obvious over Chen in view of Wang.

  • Prior Art Relied Upon: Chen (a 2012 article on hybrid envelope tracking for dual-band PAs) and Wang (a 2005 IEEE paper on envelope tracking for OFDM applications).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Chen discloses the fundamental architecture of the ’675 patent: a system using a single PA and a single power tracking supply generator to concurrently transmit multiple signals (in dual bands). Chen’s system includes envelope detectors and an envelope combiner that function as the claimed "power tracker." However, Chen does not explicitly detail the processing of in-phase (I) and quadrature (Q) signal components. Wang was introduced to supply this teaching, as it expressly discloses an envelope tracker that processes a "complex baseband signal" and calculates its amplitude based on I and Q components. Wang also teaches using Orthogonal Frequency Division Multiplexing (OFDM) signals.
    • Motivation to Combine: A POSA would combine Chen and Wang because they address the same technical problem in the same field. Chen targets modern LTE-Advanced systems, which rely on complex modulation like OFDM. A POSA implementing Chen's architecture would be motivated to incorporate Wang's explicit teachings on I/Q and OFDM signal processing to achieve the higher data rates and spectral efficiency required by such standards.
    • Expectation of Success: A POSA would have a high expectation of success because using I/Q representation for complex signals and OFDM modulation were standard, predictable, and well-understood techniques in RF communications at the time.

Ground II: Claim 12 is obvious over Chen in view of Wang and Eliezer.

  • Prior Art Relied Upon: Chen, Wang, and Eliezer (Application # 2009/0004981).
  • Core Argument for this Ground: This ground builds on the Chen/Wang combination to address claim 12, which requires the power tracking signal to have a bandwidth smaller than the overall bandwidth of the carriers.
    • Prior Art Mapping: Petitioner asserted that Eliezer teaches a high-efficiency transmitter that explicitly reduces the bandwidth of the envelope signal to improve efficiency. Eliezer describes generating a "reduced-bandwidth envelope signal" that is smoother and less demanding for the power supply to track, thereby improving efficiency and overcoming physical hardware limitations.
    • Motivation to Combine: A POSA would be motivated to integrate Eliezer’s bandwidth-reduction technique into the Chen/Wang system to gain the known efficiency benefits. This modification addresses a well-known trade-off in envelope tracking systems and represents a known method to improve a known device.

Ground III: Claims 8-10 are obvious over Chen in view of Wang and Choi.

  • Prior Art Relied Upon: Chen, Wang, and Choi (a 2010 IEEE paper on envelope tracking robust to battery depletion).
  • Core Argument for this Ground: This ground adds Choi to the Chen/Wang combination to teach the limitations of claims 8-10, which recite a power supply generator comprising a "switcher" and a "boost converter."
    • Prior Art Mapping: Petitioner argued that Choi discloses a hybrid switching amplifier (HSA) that combines a linear amplifier with a switcher (a buck converter) to achieve higher efficiency than a purely linear design. Choi also explicitly teaches a "boost converter" to make the power supply robust against battery voltage depletion, a critical feature for mobile devices.
    • Motivation to Combine: A POSA designing a mobile device based on the Chen/Wang architecture would naturally look to Choi’s more advanced power supply design. Choi’s HSA serves the same function but provides the known advantages of improved efficiency and robustness against battery sag, both of which were critical for the LTE mobile systems targeted by both Chen and Choi.

Ground IV: Claims 13-15 and 23-25 are obvious over Chen in view of Wang and Dahlman.

  • Prior Art Relied Upon: Chen, Wang, and Dahlman (a 2011 textbook on the LTE/LTE-Advanced standard).
  • Core Argument for this Ground: This ground adds Dahlman to the Chen/Wang combination to teach the specific types of carrier aggregation recited in the dependent claims: intra-band, contiguous, and non-contiguous.
    • Prior Art Mapping: Petitioner contended that Dahlman, an authoritative reference book on the LTE-Advanced standard, explicitly describes and illustrates the exact carrier aggregation schemes claimed. Dahlman’s figures show intra-band contiguous and non-contiguous carrier aggregation as defined elements of the standard.
    • Motivation to Combine: Since Chen’s system is intended for LTE-Advanced applications, a POSA would have been motivated to consult a definitive standard-defining reference like Dahlman to implement the specific carrier aggregation methods required by that standard. Combining Dahlman’s teachings was presented as an obvious and necessary implementation choice, not an inventive step.

4. Key Claim Construction Positions

Petitioner argued that the challenged claims are unpatentable even under the claim constructions adopted by an Administrative Law Judge (ALJ) in a parallel International Trade Commission (ITC) investigation. Petitioner adopted these constructions for the purpose of the IPR petition.

  • "plurality of carrier aggregated transmit signals": Petitioner applied 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 applied the ALJ's construction of "component in a voltage generator that computes the power requirement."
  • "single power tracking signal": Petitioner applied the ALJ's construction of "one (single-ended) power tracking signal."
  • Petitioner noted that applying the broader "broadest reasonable interpretation" standard, rather than the narrower standard used in the ITC, would only strengthen its invalidity arguments.

5. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 1-3, 5, 7-15, 17-21, 23-25, and 27 of the ’675 patent as unpatentable.