A 135–150 GHz High-Power Frequency Tripler With Filtering Matching Network

This letter presents a 135–150 GHz high-efficiency and -power Schottky diode-based tripler integrated with low-loss waveguide filtering matching network. The active diode monolithic microwave integrated circuit (MMIC) is matched with two waveguide filters based on coupling matrix theory for a two-port network with complex impedance terminations. The filters and the active diode MMIC are integrated via the microstrip-to-waveguide transition, allowing a compact design on the relatively higher loss MMIC. In addition, an integrated on-chip capacitor is implemented to isolate dc and RF paths. The measurement shows that with 150–200 mW input power, the maximum conversion efficiency reaches 30.5% and the maximum output power is 47 mW. All filtering poles can be observed in measurements and the return loss achieves 10–15 dB within the passband. Good agreements between measurements and simulations demonstrate the validity of the design approach.