Abstract:The research on high power 110GHz single and power-combined frequency doublers based on discrete diodes is presented in this paper. The doubler with a single Schottky diode circuit has a measured peak efficiency of 33% and bandwidth over 13.6%. Meanwhile， two different architectures with two single devices adding in-phase have been utilized to realize the power-combined doublers. The combined doubler features four discrete Schottky diodes with twelve junctions altogether soldered on two 127μm-thick ALN substrates. Both devices have demonstrated output powers more than 200mW with a pumping power over 800mW and are capable of providing more power for higher driven power.