Implementation Considerations and Performance Comparison of Variable Bandwidth FIR Filter and Phase Equalized IIR Filter

The number of taps in a FIR filter varies inversely with the filter´s transition bandwidth. A FIR filter with variable bandwidth and with a proportional transition bandwidth must also be of variable length. To avoid changing the number of taps in the FIR filter we describe a phase equalized IIR filter with weights that can be tuned to obtain the variable bandwidth, variable length impulse response without requiring a variable number of multiplies.