Intel Corp v. Qualcomm Inc

1. Case Identification

• Case #: IPR2018-01327
• Patent #: 9,608,675
• Filed: July 03, 2018
• Petitioner(s): Intel Corporation (identifying Apple Inc. as a real party-in-interest)
• Patent Owner(s): Qualcomm Incorporated
• Challenged Claims: 7-15, 17, 23-25, 27, 33

2. Patent Overview

• Title: Power Tracking for Carrier Aggregated Signals
• Brief Description: The ’675 patent relates to a system for efficiently transmitting multiple carrier aggregated radio frequency (RF) signals simultaneously. The invention purports to achieve this using a single power amplifier and a single power tracking supply generator that creates a single power tracking signal based on all transmitted signals.

3. Grounds for Unpatentability

Ground 1: Claims 11, 17, 27, and 33 are obvious over Yu in view of Wang.

• Prior Art Relied Upon: Yu (European Application # EP2442440) and Wang (a 2005 IEEE publication on envelope-tracking power amplifiers).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Yu disclosed the foundational concept of the ’675 patent: a control unit (the claimed "power tracker") that processes multiple input signals (S1, S2) to generate a single control signal (the claimed "power tracking signal") for a single power amplifier, enabling simultaneous transmission. While Yu did not explicitly mention in-phase (I) and quadrature (Q) components, Petitioner contended that a POSITA would have understood Yu's digital baseband signals to inherently possess them. The combination with Wang, which explicitly teaches calculating an amplitude signal for envelope tracking from I and Q components (sqrt(I^2+Q^2)) and using Orthogonal Frequency Division Multiplexing (OFDM) signals, rendered the claims obvious.
  • Motivation to Combine: A POSITA would combine Yu and Wang because both address envelope-tracking power amplifiers for wide-bandwidth signals. To implement Yu’s conceptual architecture, a POSITA would look to a reference like Wang for well-known and efficient implementation details, such as using I/Q signal processing to improve noise immunity and data rates.
  • Expectation of Success: The combination would yield predictable results, as using I/Q components and OFDM modulation in RF transmitters was a standard, well-established practice.

Ground 2: Claims 7-10 are obvious over Yu in view of Wang and Choi.

• Prior Art Relied Upon: Yu, Wang, and Choi (a 2010 IEEE publication on envelope tracking amplifiers robust to battery depletion).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground built upon the Yu and Wang combination and added Choi to teach specific elements of the power supply generator recited in dependent claims 7-10. Petitioner asserted that Choi disclosed a hybrid switching amplifier (HSA) containing a linear amplifier (the claimed "power tracking amplifier" of claim 7) and a switcher/buck converter (claim 8). Choi’s HSA was shown to receive an envelope signal (analogous to Yu’s control signal) and generate a supply voltage. Furthermore, Choi taught using a boost converter to receive a battery voltage and provide a stable, boosted voltage for the power tracking amplifier, satisfying the limitations of claims 9 and 10.
  • Motivation to Combine: A POSITA implementing the Yu/Wang system would seek an efficient and practical power supply generator. Choi provided a specific, known HSA design that offered high efficiency and robustness against battery depletion—a critical consideration for mobile devices. Choi’s design served the same function as Yu's generic supply module (PA') and was architecturally compatible, making it an obvious component substitution for improved performance.
  • Expectation of Success: A POSITA would have a high expectation of success, as combining a known high-efficiency power supply circuit (Choi) with a known envelope-tracking architecture (Yu/Wang) was a straightforward engineering task to achieve predictable benefits.

Ground 3: Claim 12 is obvious over Yu in view of Wang and Eliezer.

• Prior Art Relied Upon: Yu, Wang, and Eliezer (Application # 2009/0004981).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground added Eliezer to the Yu and Wang combination to teach claim 12's limitation that the power tracking signal has a bandwidth smaller than the overall bandwidth of the carriers. Petitioner argued that Eliezer directly addressed the problem that high-bandwidth envelope signals degrade power supply efficiency. Eliezer taught generating a "reduced-bandwidth envelope signal" specifically to improve the performance of the power supply, thereby explicitly disclosing a power tracking signal with a narrower bandwidth than the RF signal it tracks.
  • Motivation to Combine: A POSITA would be motivated to combine Eliezer with the Yu/Wang system to improve power efficiency, a primary goal of envelope tracking. Eliezer’s technique of reducing the envelope signal bandwidth was a known method for improving efficiency in systems with wide-band signals, making its application to the Yu/Wang architecture an obvious design choice.

Ground 4: Claims 13-15 and 23-25 are obvious over Yu in view of Wang and Dahlman.

• Prior Art Relied Upon: Yu, Wang, and Dahlman (a 2011 book on the LTE/LTE-Advanced standard).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground added Dahlman to teach the specific types of carrier aggregation recited in claims 13-15. Dahlman, a standard reference on 4G/LTE, explicitly described "intra-band carrier aggregation" (claim 13) and further detailed its implementation with both "contiguous" (claim 14) and "non-contiguous" (claim 15) component carriers. This disclosure directly mapped onto the claim limitations.
  • Motivation to Combine: Since Yu's system was for multi-signal wireless communications, a POSITA at the time of the invention would naturally look to implement the system in compliance with the prevailing LTE standard. Dahlman provided the definitive guide for LTE carrier aggregation. Therefore, it would have been obvious to apply the specific aggregation schemes from Dahlman to the general carrier aggregation architecture of Yu/Wang.

4. Key Claim Construction Positions

• "single power tracking signal": Petitioner applied the construction from a parallel ITC investigation, meaning "one (single-ended) power tracking signal." Petitioner argued that even under the Patent Owner’s broader proposed construction, the claims would still be invalid.
• "power tracker": Petitioner applied the ITC construction of a "component in a voltage generator that computes the power requirement."
• "plurality of carrier aggregated transmit signals": Petitioner applied the ITC construction, "signals for transmission on multiple carriers at the same time to increase the bandwidth for a user," while noting it believed this construction was overly broad.

5. Relief Requested

• Petitioner requested institution of an inter partes review and cancellation of claims 7-15, 17, 23-25, 27, and 33 of the ’675 patent as unpatentable under 35 U.S.C. §103.