High efficiency power combining of K band TWTAs for space communications

This paper presents a high efficiency power combining demonstration of two 100 W K-band TWTAs using a 4-port magic-T hybrid junction-based waveguide circuit. A low loss, amplitude and phase balanced, high power magic-T is designed for power combiner. Power combining efficiencies of greater than 90% and output power of more than 170W over a 0.6 GHz frequency band are successfully demonstrated. Such hybrid junctions can also be considered as elements within a corporate combining architecture for much higher power generating.