Research on Nonlinear Circuits Based on Volterra Series
|Course||Circuits and Systems|
|Keywords||nonlinear circuit Volterra series transfer function third order intermodulation(IM3)|
With the development of scientific technology, It is asked that requirement of system performance was improved incessancy. More and more attention was paid to nonlinear phenomena in recent years. Nonlinear system theory has been a hotspot of theory research.In general, it is called nonlinear circuits that there is a nonlinear component or which is worked in nonlinearly. Research on nonlinear circuits is aspect of nonlinear study.Volterra series method of studying nonlinear circuits was discussed in this paper. Volterra series theory is a effective method of studying nonlinear circuits, which can deduce the nonlinear transfer function, It is same as transfer function of linear system. The nonlinear transfer function is internal characteristics of system, which can express a nonlinear system perfectly and is dependent of choice of import signal. We can. study the internal characteristics of harmonic, gain compression/expansion, frequency modulation using nonlinear transfer function visually, The Volterra series theory is physics significance vividly.The main jobs and contributions of the paper are as follows:Firstly, the research actuality of nonlinear circuits was summarized, traditional analysis method of nonlinear circuits and the new theory and method of application to circuit and system was introduced in recent years.Secondly, the description of Volterra series application to nonlinear system was introduced. The nonlinear transfer function was obtained through many-dimensions Fourier transformation. We analyze nonlinear circuits based on nonlinear transfer function in frequency-domain. The weakly nonlinear circuit model based on nonlinear transfer function method was put forward. Sinusoidal steady-state response of weakly nonlinear system was discussed with the model. We have given an example to analyze nonlinear transfer function of weakly nonlinear circuits.Finally, the method was applied to actual nonlinear circuits. The characteristics of nonlinear in CMOS low noise amplifier of RF receiver was discussed in this paper. The third order intermodulation of CMOS low noise amplifier was calculated approximately with Volterra series. The result of simulation experiment prove that the Volterra series is effective method in analyzing nonlinear circuits.