PTAB

IPR2019-00070

ASUSTeK Computer Inc v. Maxell Ltd

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: CELLULAR TELEPHONE
  • Brief Description: The ’334 patent discloses a cellular telephone for use in a Code Division Multiple Access (CDMA) system. The technology aims to improve battery life by implementing a power control method that gradually increases bias values applied to a variable gain amplifier and a power amplifier, thereby minimizing the current required to achieve a desired transmit power.

3. Grounds for Unpatentability

Ground 1: Claims 1 and 4 are obvious over Applicant-Admitted Prior Art (AAPA) in view of Waldroup.

  • Prior Art Relied Upon: AAPA (from the ’334 patent specification) and Waldroup (Patent 6,236,863).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that the AAPA, which incorporates CDMA systems compliant with the IS-95 standard, discloses the foundational elements of the challenged claims, including a CDMA cellular telephone with open- and closed-loop power controls, a variable amplitude amplifier, and a power amplifier. Waldroup was asserted to supply the remaining limitations, specifically teaching a method of output power control in IS-95 compliant telephones. This included a maximum power detector and the use of a stored table of predefined decibel values for controlling transmission power. Petitioner contended that Waldroup's system for incrementing bias conditions based on stored values renders the gradual increase limitation obvious.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine the foundational CDMA system of the AAPA with the specific power control enhancements of Waldroup. The motivation was to fully comply with the maximum output power requirements of the IS-95 standard, which the AAPA did not explicitly detail. Incorporating Waldroup's maximum power detector and stored table of bias values was presented as a known solution to improve power efficiency, prevent circuit overheating, and prolong battery life in a predictable manner.
    • Expectation of Success: A POSITA would have a reasonable expectation of success in this combination because it involved adding a known power control technique (from Waldroup) to a standard CDMA telephone system (disclosed in AAPA) to achieve the predictable benefits of improved power management.

Ground 2: Claims 1 and 4 are obvious over AAPA in view of Mucke.

  • Prior Art Relied Upon: AAPA and Mucke (Patent 5,548,616).
  • Core Argument for this Ground:
    • Prior Art Mapping: Similar to the first ground, Petitioner asserted that AAPA provides the basic CDMA telephone framework. Mucke, which is also directed to power control in CDMA mobile terminals, was argued to teach the missing elements. Specifically, Mucke discloses controlling the bias conditions of a power amplifier jointly with the gain of a variable amplitude amplifier to maintain high power efficiency. Petitioner highlighted Mucke’s disclosure of both analog and digital bias control blocks for gradually increasing the bias condition corresponding to gradual variations in gain control.
    • Motivation to Combine: A POSITA would be motivated to modify the AAPA system with the power control teachings of Mucke for reasons similar to those for combining with Waldroup. Both references address the same technical problem in the same field. The primary motivation was to improve the power efficiency of the transmitter, which in turn extends battery life, prevents overheating, and reduces interference by allowing for gradual increases in power.
    • Expectation of Success: Success was expected because the combination involved applying well-known and conventional elements (Mucke's bias control) to a standard system (AAPA), with each element performing its usual task to achieve the predictable result of enhanced power efficiency.

Ground 3: Claims 1 and 4 are obvious over AAPA and Waldroup/Mucke in view of DiPiazza.

  • Prior Art Relied Upon: AAPA, Waldroup (Patent 6,236,863) or Mucke (Patent 5,548,616), and DiPiazza (Patent 5,101,173).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground was presented as an alternative in case the primary combinations were found insufficient. Petitioner argued that DiPiazza explicitly teaches a stored program controller that uses a look-up table embedded in memory to control both the gain of a variable amplitude amplifier and the DC bias condition of a power amplifier. This was asserted to cure any perceived deficiency in AAPA, Waldroup, or Mucke regarding the control of bias and gain using a stored function that defines their relationship. DiPiazza's disclosure of operating over a 30dB range was argued to imply a multi-step, "gradual" increase in bias values.
    • Motivation to Combine: A POSITA, having combined AAPA with Waldroup or Mucke, would be further motivated to incorporate the teachings of DiPiazza to achieve more precise control of bias and gain values over a wide range of power levels, a known requirement for CDMA systems. Using DiPiazza's look-up table method would also reduce the computational complexity of the controller, a clear design advantage.
    • Expectation of Success: The combination represents the integration of well-known ideas in a predictable manner to achieve the expected result of more accurate and efficient power control.

4. Key Claim Construction Positions

Petitioner argued that several key claim terms were indefinite but proposed constructions under the Broadest Reasonable Interpretation (BRI) standard for the purpose of the inter partes review (IPR).

  • "gradually": Petitioner contended this term is indefinite as the patent provides no standard to measure how "gradual" an increase must be. For the IPR, Petitioner proposed the construction "increases by steps to the maximum value," arguing this aligns with the specification’s examples of stepped, not continuous, increases.
  • "when said cellular telephone is very far from the cell-site station": This was also argued to be an indefinite and subjective term of degree. Petitioner proposed the construction "when said cellular telephone is at a distance from the cell-site that requires transmission at the maximum allowable output power level," asserting this provides an objective standard consistent with the patent's disclosure.
  • "variable amplitude amplifier": Petitioner noted this term has no accepted meaning in the field. For the IPR, Petitioner adopted a construction from a related district court case: "an amplifier whose output amplitude may be varied and that provides a variable gain in response to a control signal."

5. Arguments Regarding Discretionary Denial

  • Petitioner acknowledged that another IPR petition (IPR2019-00088) had been filed against the same patent by a different party (Blackberry) shortly before its own filing. Petitioner argued that the Board should exercise its discretion to institute this IPR because the petitioner had not previously challenged the patent, the time elapsed between the two petitions was de minimis, and the petitioner had not yet received the patent owner's preliminary response from the first petition.

6. Relief Requested

  • Petitioner requests institution of IPR and cancellation of claims 1 and 4 of Patent 6,973,334 as unpatentable.