Design of a V-band power amplifier/combiner based on spatial power-combining technique

A V-Band solid-state power amplifier/combiner is demonstrated in this paper. 8-way radial-line power combiner/divider and microstrip-to-waveguide transitions are proposed and designed. The insert losses of the passive combiner/divider is 2.6 dB as tested in back-to-back configuration, which indicates about 0.3 dB insert loss of the combine/divider network, and exhibits a combining efficiency of 93% at 60 GHz. Active circuit test results show the maximum total output power is 18 dBm. Further discussion is presented to analyze the reasons of power degradation, this is mainly due to the wildly unequal phase delays of the power combine/divider, and the position of the coaxial probe obviously affects the uniformity of the combine/divider network.