A Compact Ka-Band Broadband Waveguide-Based Traveling-Wave Spatial Power Combiner with Low Loss Symmetric Coupling Structure

A compact Ka-band broadband waveguide-based traveling-wave spatial power combiner is presented. The low loss micro-strip probes are symmetrically inserted into both broadwalls of waveguide, quadrupling the coupling ways but the insertion loss increases little. The measured 16 dB return-loss bandwidth of the eight-way back-to-back structure is from 30 GHz to 39.4 GHz (more than 25%) and the insertion loss is less than 1 dB, which predicts the power-combining efficiency is higher than 90%.