Investigation Of Nonlinear Characteristics Of High Power Varactor And Transient Voltage Suppressor

With the rapid increase of power and frequency in wireless communication devices,the nonlinear characteristics of varactor and transient voltage suppression diodes in the wireless devices will play a significant role in electronic circuits,which will create a great challenge to the design of wireless devices.The traditional microwave analysis method is not suitable for analyzing the nonlinear characteristics of the above devices.How to predict the output of such nonlinear devices accurately and quickly is a difficult problem.In this research,the nonlinear theory is deeply studied.Combining the theory with the actual engineering requirements,an effective and accurate model is successfully established to simulate the nonlinear characteristics of the parts.The research on nonlinear devices is an important problem in circuit theory.At present,there are no breakthrough research results in China.This paper mainly modelled the nonlinear characteristics of varactor and transient suppression diodes.Based on the theory of capacitive adjustable diodes and transient suppression diodes,the physical reasons of the nonlinear characteristics are analyzed from the mechanism.There are some innovations in this paper.For the varactor,the nonlinear behavior is predicted by mathematical methods,and the correctness of the mathematical derivation is verified by experiments.On this basis,a simple and effective model is proposed,and the mathematical expression of the harmonics on the load is given.The simulation experiment of complex impedance shows that this method is applicable to engineering practice.For transient suppression diodes,this paper successfully extracted the X parameter from the circuit principle design,and then trained an RNN neural network model to fit the input and output,which can quickly and accurately predict the output and reduce the tedious microwave testing work.Finally,an example of the parameter fitting of varactor was given.This paper described a systematic and detailed engineering test method.After reducing the influence of PCB board by the method of de-embedding,the parameters were obtained by one parameter extraction and three times fitting.In the process of parameter fitting,this paper creatively proposed to separate the parameters producing fundamental waves from those producing harmonics.We first fitted the parameters of fundamental waves,then the parameters of harmonics,which effectively reduced the time required for fitting and improved the accuracy of the results.