Apple Inc v. Maxell Ltd

1. Case Identification

• Case #: IPR2020-00203
• Patent #: 6,408,193
• Filed: December 20, 2019
• Petitioner(s): Apple Inc.
• Patent Owner(s): Maxell, Ltd.
• Challenged Claims: 1, 6, and 7

2. Patent Overview

• Title: Cellular Telephone
• Brief Description: The ’193 patent describes a cellular telephone for use in a Code Division Multiple Access (CDMA) system. The invention purports to improve power efficiency by using a controller that adjusts a power amplifier’s bias based on a corresponding gain value for a variable amplitude amplifier, with the relationship between bias and gain data stored in a memory.

3. Grounds for Unpatentability

Ground 1: Obviousness over Waldroup and Nakayama - Claims 1, 6, and 7 are obvious over Waldroup in view of Nakayama.

• Prior Art Relied Upon: Waldroup (Patent 6,236,863) and Nakayama (Japanese Unexamined Patent Application Publication No. JP H10-285059).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Waldroup, the primary reference, disclosed a CDMA cellular telephone that meets most limitations of the challenged claims, including the use of a variable amplifier and a power amplifier for output power control. However, Waldroup taught using a fixed-bias power amplifier, which is inefficient at lower power levels. Petitioner asserted that Nakayama, the secondary reference, addressed this exact problem by teaching a controller-based system that adjusts a power amplifier’s bias responsive to transmission power. Nakayama explicitly disclosed storing discrete bias and gain values in memory and using that data to jointly control the amplifier chain for improved power efficiency. Petitioner contended that combining Nakayama’s controller and amplifier biasing scheme with Waldroup’s CDMA telephone architecture would render the challenged claims obvious.
  • Motivation to Combine: Petitioner presented several motivations for a person of ordinary skill in the art (POSITA) to combine the references. First, a POSITA would have sought to improve the power efficiency of Waldroup’s transmitter, a well-known design goal. Nakayama directly taught that adjusting power amplifier bias according to transmit power levels improves efficiency, providing an express reason to modify Waldroup. Second, since CDMA phones frequently operate well below maximum power, the inefficiency of Waldroup’s fixed-bias amplifier would be a known problem that Nakayama’s system was designed to solve. Third, the combination would involve replacing known functional blocks in Waldroup with the analogous, improved blocks from Nakayama to achieve the predictable result of increased battery life and better signal quality.
  • Expectation of Success: Petitioner argued that a POSITA would have had a reasonable expectation of success in combining the teachings. The modification would involve substituting the transmitter components of Waldroup with the well-known, controller-based transmitter components of Nakayama, a straightforward integration that would yield the predictable benefits of improved power efficiency.

4. Key Claim Construction Positions

• “a cellular telephone adapted to be used in a CDMA system”: Petitioner argued that this preamble term was a binding limitation. The applicant relied on this phrase during prosecution to distinguish the invention from prior art that taught a more general "radio telephone," thereby making the preamble essential to defining the claimed invention.
• “variable amplitude amplifier”: Petitioner proposed this term be construed as “an amplifier whose output amplitude may be varied and that provides a variable gain in response to a control signal.” This construction was based on an agreement between the parties in parallel district court litigation and was asserted to clarify a term not commonly used in the art.
• “a function defining a relation between bias data and gain data stored in said memory”: Citing party agreement in litigation, Petitioner proposed construing this term to mean “a relationship between bias data and gain data stored in memory such that each gain data value has a corresponding bias data value.” This construction emphasizes the one-to-one mapping central to the alleged invention.
• “voice signal code” / “voice code signal”: Petitioner argued these two phrases should be construed to have the same meaning. The petition asserted that the specification of the ’193 patent used the terms interchangeably when describing the same signal processing path, indicating no intended distinction in meaning.

5. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under 35 U.S.C. §314(a) would be inappropriate, specifically addressing the General Plastic factors because a prior IPR on the same patent (filed by an unrelated party) had been denied institution.
• Petitioner asserted that all factors favored institution of the current IPR. Key arguments included that Apple had not previously filed a petition against the ’193 patent and that the current petition relied on entirely different prior art references and arguments than the previously denied petition. Therefore, Petitioner would gain no unfair tactical advantage from the prior proceeding, and the Board would not be reviewing duplicative arguments or wasting resources.
• Petitioner also argued against denial based on the parallel district court litigation, noting that the case was in its early stages, no significant work on invalidity issues had been performed by the court, and no Markman hearing had been held.

6. Relief Requested

• Petitioner requested the institution of an inter partes review and the cancellation of claims 1, 6, and 7 of the ’193 patent as unpatentable.