An enhanced efficiency 170-260 GHz frequency doubler based on three points resonance matching technique

This paper presents a full-band frequency doubler (170-260 GHz) with enhanced efficiency based on Schottky diodes. To achieve broadband matching between the matching circuit and the Schottky diode, a three points resonance matching technique (TPRMT) is employed. This technique is developed by considering the embedded impedance matching at three distinct frequency points: upper, middle, and lower, thereby guiding the design of the peripheral matching circuits. In comparison to single frequency point matching, this approach effectively suppresses sideband performance degradation, resulting in improved efficiency. Additionally, the peripheral matching circuits are meticulously designed to fulfill a resonance clockwise impedance trajectory, facilitating matching at the aforementioned three frequency points. Due to the limitation of the input power source, measurements were conducted only within the 170-237 GHz frequency band. The measured results show that the doubler achieves an efficiency ranging from 8.4 % to 14.1 % under an input power of 130-175 mW. The good consistency between simulation and measurement validates the significant advantages of TPRMT.