A Self-Biased 210–260 GHz Frequency Tripler Based on Planar Schottky Diodes

This paper describes the design and demonstration of a hybrid integrated 210~260 GHz self-biased frequency tripler based on planar Schottky diodes. Two Schottky diodes are placed in reversed parallel on the circuit. Then, a self-bias resistor is connected to the circuit to provide a DC bias. The bias voltage is changed by adjusting the resistances, so that the tripler can fit in the best working state. In addition, the current saturation effect is considered in the nonlinear simulation of the circuit to obtain more accurate simulated results. The proposed tripler was fabricated on a 50-um thickness quartz substrate circuit and housed in split waveguide blocks. Measured results show that the tripler exhibits a peak output power of 6.4 dBm at 220 GHz with 20 dBm pumped power and a wide 3 dB bandwidth of 21 % from 210 GHz to 260 GHz with a conversion efficiency above 2.2%.