0.67THz宽带谐波混频器设计

Design of 0.67THz sub-harmonic mixer

为研制太赫兹多频段高灵敏度探测仪,依靠太赫兹砷化镓平面肖特基二极管的非线性特性,结合石英薄膜工艺,设计了宽带0.67THz谐波混频器,并分析了砷化镓平面肖特基二极管性能表征参数指标对太赫兹混频器性能的影响。0.67THz谐波混频器采用整体综合的设计方法,结合电气仿真软件ADS和电磁仿真软件HFSS,优化电路中不连续性微带与波导之间的电磁空间耦合效率,以混频器的变频损耗为优化目标,最终实现0.67THz谐波混频器仿真设计。0.62~0.72THz射频范围内,混频器单边带最低变频损耗小于8dB,本振功率小于4mW,本振端口与中频端口、射频端口与中频端口之间隔离度大于-30 dB。

Aiming to develop terahertz multi-band high sensitivity receiver, a broadband 0.67 THz sub-harmonic mixer is developed based on the nonlinearity of terahertz GaAs plannar Schottky diode and quartz film thinning process. The influence of the performance parameters of Schottky diode on the performance of terahertz mixer is analyzed, which provides a theoretical guide to diode selection and mixer evaluation. In the design of 0.67 THz sub-harmonic mixer, the synthetic design method is adopted by using the electrical and electromagnetic simulation software, and the optimization is made on the coupling between the discontinuous microstrip and waveguide in order to minimize the conversion loss. In the design of 0.67 THz sub-harmonic mixer, the best simulated conversion loss is less than 7 dB over 0.62-0.72 THz frequency range, the LO drive power is less than 4 mW, and the isolations are above-30 dB between LO port and IF port, RF port and IF port.