Low-distortion MMIC power amplifier using a new form of derivative superposition

Reduction of interchannel interference produced by a power amplifier near 1 -dB compression is a key concern for the wireless communications industry. In this paper, we present a 100-mW monolithic-microwave integrated-circuit (MMIC) power amplifier designed using a novel form of the derivative superp osition method. The measured results of the MMIC power amplifier showed a t wo-tone carrier-to-interference (C/I) ratio of 45 dBc with an efficiency of 22.5% when backed off by 4.5 dB from the 1-dB compression point. We demons trate that the MIMIC power amplifier represents a good compromise between C /I ratio, output power, efficiency, and gain at the cost of an increase in total gate width, by comparing it to class-A, class-AB, and class-B single field-effect-transistor amplifiers.