Quasi-optical and spatial power combining

Abstract—Quasi-optical power-combining techniques have been developed to address fundamental limitations in solid-state devices and circuits. These techniques have been applied to oscillators, amplifiers, frequency-conversion components, and control circuits. This paper surveys progress in the development of quasi-optical array systems operating in the microwave and millimeter-wave regime, focusing primarily on the progress in power amplifiers. Index Terms—Active arrays, amplifiers, power combining, quasi-optics, spatial power combining. I