Design of a W-band single-substrate single-waveguide power-combined frequency doubler

A W-band single-substrate single-waveguide power-combined frequency multiplier is designed with commercial planar varistor DBES105a. Four diodes are mounted on the double-sided finline and suspended-stripline substrate, which situates along the center of the E-plane of a single transmission waveguide. The measured results of the biased W-band frequency doubler show that the output power is 5-9 dBm with 3-8% conversion efficiency across an 86-96 GHz band at room temperature.