High Efficiency PA Design Strategy at X-Band

Abstract

There is an growing demand for high efficiency power amplifiers at high frequencies, X-band and above. It is well understood that design strategies targeting high efficiency requires output IV waveform engineering; switching the mode of device operation from the Class A or AB modes to the Class B or C modes. Unfortunately, this mode switch results in a significant reduction in gain, which since the maximum amount of gain at high frequencies is limited, can result in degraded rather than enhanced power added efficiency. An improved design strategy, incorporating input IV waveform engineering, can be used to minimize this gain reduction thus providing for improved power added efficiency.