Microwave device and design technology impacts on the performance of power amplifiers in mobile video links

Capabilities of modern communication systems are progressing at a breathtaking pace as the underlying technologies mature. Large amounts of digital information are being sent through mobile transceivers using complex digital modulation formats that require that amplitude and phase distortion (AM/AM, AMIPM, IM3 levels) be kept to a minimum for high reliability throughput. Standards at the Federal level have been established to ensure that system interference is minimized among co-located users, which relies on highly linear operation of the electronic components in the transmission link. At the same time, remote controlled mobile data collection systems are being used to relay that information (video, voice and/or telemetry) from remote terrain back to a fixed or mobile receiving location. To extend the useable life of critical mobile data links for a given mission, higher DC to RF efficiency is desired of the transmission gear, especially the power amplifier. Improvements in PA linearity and efficiency are necessary to support advances in modern mobile communication technology. This paper describes the importance of power amplifier linearity and efficiency to modern digital communication system applications.