A 170–230 GHz High-Power Frequency Doubler Based on a GaAs MMIC Process

This letter reports a high-performance frequency doubler operating at 170–230 GHz based on a GaAs monolithic microwave integrated circuit (MMIC) process. The frequency doubler was designed with a balanced structure and the MMIC was inserted between two $E$ -plane split-waveguide blocks. A “Pass-by” shaped biased filter was employed to improve the operation bandwidth. Measurement results showed that the doubler delivers continuous wave (CW) output power of 42–78 mW from 170 to 220 GHz with an efficiency of 14%–26%. With the increase of bias voltage, higher output power at higher frequency can be achieved, delivering a CW output power of 54–107 mW from 192 to 226 GHz at an efficiency of 18%–36%. At a very high input power level (600 mW), a maximum CW output power of 165 mW at 215 GHz with an efficiency of 27.5% has been demonstrated.