DESIGN OF INFINITE IMPULSE RESPONSE FILTER USING GENETIC ALGORITHM TO MINIMIZE THE RIPPLE IN PASS BAND AND STOP BAND AND TO DECREASE THE TRANSITION WIDTH

The design of infinite impulse response (IIR) filter has increased attention in the field of signal processing in recent years. This paper presents the design of Band Pass Butterworth and Chebyshev infinite impulse response (IIR) filters with requirement of less ripples in pass band and stop band and small transition width. The Di fferent optimization algorithms are available in literature but the Genetic Algorithm (GA) has been used here for the design of Butterworth and Chebyshev infinite impulse response (IIR) filters due to its simplicity and ease of implementation. The Genetic Algorithm (GA) is a general optimization algorithm, but it needs to be modified to design a digital IIR filter design. These modifications include a method for mapping a filter to an element, evaluation of the fitness function of the IIR filter, creation of an initial population of the IIR filter. The Genetic Algorithm is applied in order t o obtain the designed magnitude response (Hn) as close as possible to desired magnitude response (Hd) .The proposed Algorithm has been tested for band pass Butterworth and Chebyshev IIR filter design problems. Keywords-Butterworth Filter, Chebyshev Filter, Infinite Impulse Response (IIR) Filter, Band Pass Filter, Genetic Algorithm, Fitness Function, Generations, Crossover