Design of Programmable Digital Filter: Band Pass Using Second Order All Pass Transformation and Coefficient Decimation

In this paper, the design of a computationally efficient programmable digital filter (PDF) is presented. The centre frequency and bandwidth of this filter can be for the desired one without updating the filter coefficients. The warped infinite impulse response (W-IIR) filters, obtained by replacing each unit delay of an IIR filter with an all pass filter, are widely used for various audio processing applications. However, W-IIR filters fails to provide programmable bandwidth band pass responses for a given center frequency using first order all pass transformation. To overcome this drawback, the design is accomplished by combining W-IIR filter with the coefficient decimation (CDM) technique.