Digest of American Radio LLC v. Qualcomm Inc.No. 2013-1641, -1642, -1643, -1644. (Fed. Cir. Aug. 22, 2014) (non-precedential). On appeal from C.D. Cal. Before Lourie, O’Malley, and Chen.

Procedural Posture: Patent holder American Radio appealed a judgment of non-infringement following stipulation of non-infringement by the parties after the district court issued its claim construction. CAFC affirmed.

  • Claim Construction: The Federal Circuit upheld claim constructions of a group of “analog signal limitations,” “digitized signal,” and “frequency to which the input signal is shifted, including shifting the signal to zero Hertz” based on usage in the specification and in the prior art. The district court correctly construed the analog signal and digitized signal claim terms to be limited to waveforms at the carrierfrequency since the patents at issue consistently used these signal limitations to describe receiving an analog waveform at the carrier frequency and then digitizing the waveform before down-converting to a lower frequency. The district court also correctly construed the Intermediate Frequency (IF) limitation to include shifting a signal to zero Hertz. The district court noted that prior art discussed in the patents at issue (as well as uncited prior art patents) defined an IF frequency to include zero Hertz and that the specifications of the patents at issue were not inconsistent with this definition.