Evolutionary Design of a Second-Order Butterworth Lowpass Filter

The traditional design method of filter had too much human intervention, a very tedious design process. Precision of parameters was lower for the designed filter, bandpass edge of attenuation characteristics was not enough steep and filtering quality was lower. In order to overcome these shortcomings, an evolutionary design method for an analog filter is presented in the paper, according to basic principles of evolutionary design for circuit. The method is structure of a second-order Butterworth lowpass filter is devised by genetic programming. Optimization design of parameters for the filter is realized by improved adaptive genetic algorithm. Performance indexes for the filter are analyzed by simulation software. Design results have been simulated and verified. Experiment shows that values of evolutionary parameters are in line with theoretical values exceedingly for the filter, and simulation results are satisfying.