1THz High Harmonic Mixer

Terahertz wave has become the focus of research in various fields due to its superior characteristics.The realization of the 1.03THz power amplifier in the US"DARPA plan" has seen the dawn of high-speed communication.At present,the domestic terahertz technology is also concentrated in the lower frequency section of the terahertz wave,mainly below 1THz,and the higher frequency bands of the terahertz wave have not been touched by the research environment restrictions.The future high frequency and high speed information transmission is bound to be the mainstream of development.The higher frequency terahertz receiver is also one of the main topics of future research.As the first stage of the terahertz receiving system,the performance of the mixer affects the performance of the whole system.The main part of this thesis is the mixer,which is the most important part of the terahertz receiving system.Terahertz mixer mainly transfers the received high frequency terahertz signal to the low frequency band for signal processing.The fundamental mixer has a high demand on the source.At present,there is no higher power terahertz source in China.Therefore,based on the nonlinear characteristics of the diode,this thesis uses the reverse parallel diode to study the high harmonic mixer.The local oscillator frequency is only 1/10 of the RF frequency and even lower,which can greatly reduce the demand for the source.In this thesis,a Schottky diode suitable for high frequency terahertz mixing is studied.According to the carrier characteristics and structure of Schottky diode,the SPICE parameter model of diode nonlinear Schottky junction and the three dimensional equivalent model of parasitic parameters are established respectively.Then the non linear characteristic of the diode is simulated.Secondly,the harmonic mixer is based on the harmonic mixer.According to the domestic processing technology level,the circuit is optimized,and the combined optimization circuit is simulated by the three-dimensional electromagnetic simulation and harmonic balance method.Finally,according to the experimental results,the feedback correction diode model and the circuit parameters are fed back to complete the mixer.The joint simulation and experimental results of the mixer verify that the 1THz high harmonic mixer is feasible.The simulation results of the ten harmonic mixer show that the frequency conversion loss is less than 40dB in the 1000GHz-1200GHz frequency range,and the optimal frequency point can reach 22dB.After completing the optimization simulation,the ten harmonic mixer is experimentally studied.Ten harmonic mixer test results,in the 980GHz-1130GHz frequency range,mixer has output,the best can achieve 60dB.In the simulation of the ten harmonic mixer,it is found that the reliability of the ten harmonic mixer is low,so the reliability of the mixer is increased in this thesis,and the 1THz twenty-eight harmonic mixer is also studied.The simulation result of the twenty-eight harmonic mixer is that the frequency conversion loss is less than 50dB in the 1000GHz-1200GHz frequency range.In 1060GHz-1140GHz,the frequency conversion loss is less than 40dB,and the optimal frequency can reach 30dB.The thesis of 1THz high harmonic mixer in this thesis is an exploration of terahertz higher frequency applications.It can provide a reference for 1THz terahertz receiver research.Due to the limitation of the domestic processing technology and research conditions,the test results failed to achieve better results,and many works need further improvement.