Several Kinds Of Nonlinear Circuits' Numerical Value Analysis And Optimal Design

Along with the progress of science and technology, electronic technology has gained swift and violent development. New electronic device turned up continuously, so nonlinear circuits have received a wide application. Therefore, analyzing the specific property of nonlinear circuits and taking it to be used take an important part in society, which will have a wide application prospect and be bounded up with the development of national economy tightly. It will have some theoretical meaning and practical value.It is a tendency that all kinds of subject permeate each other greatly with the development of science and technology. The thought of the medical diagnosis was extended to other engineer fields. Fault diagnosis, which is a new subject, has turned out to keep watching on equipment's state and diagnosing their fault. For the exact mathematics models of analog circuits are nonlinear, and our understanding about circuits is getting deeper and deeper, exploring nonlinear circuits'fault diagnosis is urgently asked for. So it has great potent economic and social benefit to develop fault diagnosis technology.The combination of wavelets and neural-network is another active field for research. Wavelets neural network combined neural-network's self-study specific property with wavelets'partial specific property, it possessed self-suitable distinguish and good tolerance specific property. Therefore, it will open up a new way to diagnose fault. It not only widens the application fields of neural-network, fuzzy theory and wavelet transformation method, but also makes a breakthrough in fault diagnosing. So it will promote the theory and methods of analog circuits fault diagnosis.Nonlinear dynamic circuits belong to nonlinear motive power system. The research of chaos in circuits system has been a unique subject. We have been doing research on nonlinear circuits'chaos for more than 20 years. In chaos phenomenon and chaos appearance, through many scholars'uninterrupted study, not only some circuits for researching the mechanism of chaos were constructed, but also some useful circuits'chaos behavior was explored deeply. We made great progress.Circuit's optimal design is to regulate circuit's some parameters until its performances reach satisfied requirement. But before doing that, the circuit must have basic function and under some restrained conditions. Before building hardware circuits, analog analysis and optimal design to circuit will save a lot of time and fund, as well will shorten the time of production's development.First, this dissertation which united a negative resistance oscillator circuit simulated nonlinear circuit's numerical value calculation by using language C and MATLAB applied five-order Runge-Kutta-Fehlberg method. And then, it predicted that nonlinear frequency-spectrum analysis technology would be widely used in fault diagnosis of nonlinear system after diagnosing a nonlinear circuit through Volterra series.Second, by uniting Fan De Po oscillator circuit, it realized continuous and dispersed wavelet transformation calculation, rebuilt one-dimension wavelet coefficients, and did some research on fault diagnosis with wavelets analysis. So it laid a foundation on the application of wavelet transformation in nonlinear circuits. By respectively using PSPICE and MATLAB, it showed the chaos phenomenon in Colpitts oscillator circuit and Lorenz system, and calculated the power spectrum of Lorenz system by using MATLAB. Furthermore, the author observed the evolution process of variables in parameter and phase space, got a clear understanding on how to get to chaos, and laid a foundation on analyzing the power behavior of nonlinear system's. It showed the specific process of optimal design, which respectively used three kinds of different methods (SGA, PSPICE and DFP method) by uniting three kinds of nonlinear circuits. So, there opened a window to popularize the application of optimal algorithm in nonlinear circuits. Therefore, it will possess practical value and will help to raise the efficiency of new electronic circuit production.At the end of this dissertation, the research results were summarized and the further investigative directions were pointed out.