Based Digital IIR Filter Design

a fundamental aspect of signal processing is filtering. Filtering involves the manipulation of the spectrum of a signal by passing or blocking certain portions of the spectrum, depending on the frequency of those portions. In this paper, Digital filters are designed using frequency specifications. Matlab provides different options for digital filter design, which includes function, calls to filter algorithms and a graphical user interface called Sptool. A variety of filter design algorithms are available in Matlab for both IIR and FIR filters. This paper discusses the different options in Matlab to design digital IIR filter. Four ty Elliptic. Results obtained are plots of magnitude response, phase response, impulse response and pole type of filter. Results show that the graphical user interf making function calls to the filter algorithms. Results are also compared with the standard filter design tool i.e. FDA tool of MATLAB. Digital filtering is one of the most power implemented on DSP processor or in software. In both the cases a fair amount of programming is required. Using interactive software, such as MATLAB, it is now possible to place more e concepts than on programming algorithms. Interesting practical examples can be discussed, and useful problems can be explored. MATLAB is a high performance language for technical computing. It integrates Computation, Visualization and programming in an easy to use environment. Digital IIR filters have been derived from their analog counterparts. Classical prototype analog filters are Butterworth, Chebyshev I, Chebyshev II and Elliptic. Parameters required designing IIR frequency, Pass band ripples and Stop impulse response and order of the filter can be generated. Basic prototype IIR filters are of four types. First is Butterworth filter, whose magnitude response is maximally flat from Ω = 0 to Ω = ∞. types, Chebyshev I and Chebyshev II. The Chebyshev Type I filter minimizes the absolute difference between the ideal and actual frequency response over the entire pass band. Stop band response is maximally flat. The transit Butterworth filter. between the ideal and actual frequency response over the entire the stop band. Pass band response is maximally flat. Elliptic filters are equiripple in both the They generally meet filter requirements with the lowest order of any supported filter type. Given a filter order band ripple Rp in decibels, and at . Magnitude response of these classical IIR filters is shown in following figures1, 2, 3, and 4 respectively. .ijecse.org Based Digital IIR Filter Design Samarjeet Singh , Uma Sharma 2 Engineering BBDIT, Ghaziabad. 1 [email protected] 2 [email protected] pes of IIR filters are studied, Butterworth, Chebyshev I, Chebyshev II and ace Sptool is a quicker and simpler option than the option of