Abstract:At present, the frequency spectrum resources in the microwave band are becoming increasingly scarce. The exploration of the terahertz band has provided new ideas for solving this problem. Terahertz technology is widely used in many fields, such as communications, radar and imaging. Terahertz mixer is a critical device in the terahertz transceiver system. Therefore, the study of terahertz mixer is very important. A 330 GHz sub-harmonic mixer based on GaAs planar Schottky diode is presented. An integrated design method is utilized. And a co-simulation in High Frequency Structure Simulator(HFSS) and Advanced Design System(ADS) is implemented. The circuit discontinuity is characterized by the simulation results of HFSS. The characteristics of the circuit transmission and the nonlinear characteristics of the diode are characterized by ADS simulation results. By optimizing the transmission line parameters, the purpose of optimizing the circuit is realized. This method increases the optimization range and reduces the design difficulty. Simulated results show that conversion loss of this mixer is less than 8 dB from 300 GHz to 350 GHz.