The Relation Between IIR Pole and FIR Zero
Donald C. Daniel · 2011
A digital filter representing an isolated zero is derived from a digital filter representing an isolated pole. Even though the pole is IIR, the zero is unavoidably FIR. In a previous paper [1], an isolated IIR pole and an isolated FIR zero were presented with their associated gain functions. The pole was derived in [2]. We now derive the zero from the pole. We now repeat the pole and its gain function as given in the previous papers. Let t be the time step, a constant. The sample number is k, the input stream is xk, the output stream is yk. A pole at (�p,!p) radians/sec is given by: