High Power 170 GHz Frequency Doubler Based on GaAs Schottky Diodes

The research on high power 170 GHz frequency doubler based on the GaAs Schottky diodes is proposed in this paper. This basic doubler cell is developed with a 50-mu m-thick, 600-mu m-wide, and 2-mm-long AlN substrate with high thermal conductivity to reduce the thermal effect. Besides, power combined frequency doubler has been fabricated to improve the power capacity by a factor of two. Great agreement has been achieved between the simulated results based on electro-thermal model and measured performances. At room temperature, the 3 dB bandwidth of the single doubler based on GaAs Schottky diodes is 11.8% over the frequency range from 160 to 180 GHz with pumping power of 150 to 330 mW. And the peak efficiency of the doubler is measured to be 33.1%, while the maximum output power is 101.7 mW at 174.08 GHz. As for power combined circuit, the best efficiency is 30.1% with a related output power of 204.6 mW. The proposed methods of developing high power multipliers can be applied in higher frequency band in the future.