Design of a new millimeter wave power combiner based on multi-way ridged waveguides

A new millimeter wave spatial power combiner based on broadband multi-way ridged waveguides is designed. The device is composed of a multi-step impedance transformer and eight ridged waveguides. Since the ridged waveguides provide a consistent impedance transformation and a broad band working frequency, a millimeter wave solid-state power amplifier based on the combiner demonstrates an output power of more than 5 W at 40 GHz and greater than 10 W over the 30 GHz to 34 GHz band. Measured results show that all the ridged waveguides have the high uniformity of amplitude and phase, and the combiner has demonstrated operation over a broadband of 30 GHz to 40 GHz with more than 10 dB return loss and less than 0.8 dB insertion loss.