To implement evolutionary design of analog circuits with larger scale and higher speed

we proposed a multi-stage adaptive Genetic Algorithm.It features an encoding-decoding scheme supporting creation of circuit structures and standard values (i.e.discrete values in common use) of components

a multi-objective fitness evaluation method based on PSpice simulation and penalty for the circuit size

and a genetic parameter adaptation technique considering the different effect of each locus on fitness and tracking the course of evolution.It is suggested by the experiment results of a series of active filter that the approach discussed can firstly search feasible circuit structures

then find an optimal combination of component values

and finally provide a simplified circuit with a response very close to the design target

whilst only a modest computational resource that a PC can provides is required.