Combiner-based method for efficiency enhancement of power amplifiers operating in a broad dynamic range

Radio frequency (RF) and microwave power amplifiers using divider–combiner architecture are important blocks of rapidly developing middle and high power RF and microwave systems used in radars, communication, directed energy, electronic warfare, air traffic control, and scientific facilities such as particle accelerators. Many of these amplifiers need to operate in a wide dynamic range of output power levels. For conventional amplifiers that significantly reduces actual efficiency compared to the maximum efficiency attainable at maximum output power levels. Efficiency of a high power amplifier system can be made close to efficiency of a single amplifying module at compression if graceful degradation performance is dramatically improved. The approach is based on dynamic switching on and off some of the amplifying modules, and switchable termination of the corresponding ports of a reactive combiner with externally controlled phasing. The power-scalable method is validated with simulations demonstrating capability of power dynamic range exceeding 13 dB at nearly saturated efficiency of the active power modules and low insertion loss imposed by the passive RF components.