Broadcom Corp. v. Emulex Corp., No. 12-1309 (Fed. Cir. 2013)Annotate this Case
The patent concerns digital communication systems with data transceivers capable of receiving multiple, analog, high-speed, serial data signals. Once received, the analog data signal must be converted into a digital signal through a process called “sampling” that involves measuring the amplitude of the analog signal at precisely timed intervals to extract the data carried in the analog signal. The receiver needs a way to discern the proper rate at which to sample the analog signal and a means for generating a sampling signal with the appropriate frequency. When data is sent through cables over long distances, the incoming signal frequency can vary. To compensate for variances, receiver circuits adjust the sampling signal to match the frequency and phase of the incoming data signal. The district court held that Emulex infringed the patent. The Federal Circuit affirmed, holding that the patent would not have been obvious at the time of invention and that the district court properly exercised its discretion in granting a permanent injunction with a well-crafted sunset period.