A 120-W X-band spatially combined solid-state amplifier

In this paper, we present new results in the development of a broad-band sp atial power-combining system implemented in a standard X-band waveguide env ironment. Using 24 off-the-shelf GaAs monolithic-microwave integrated-circu it (MMIC) power amplifiers integrated with tapered-slot antenna arrays, the new combining circuit produced up to 126-W maximum power output with a gai n variation of +/-1.9 dB within the band of interest (8-11 GHz), This hybri d circuit combiner is transparent to the device technology, and also provid es an excellent heat-sinking capacity, sustaining as much as 415 W of de po wer consumed by the MMIC amplifiers. The modular architecture allows easy m aintenance, variable output power level, and modular assembly. Results on g raceful degradation are also presented, showing superb tolerance to device failure.