Selective linear phase bandpass distributed filters with controlled group delay and equiripple passband loss

A closed-form solution is described for the construction of even-degree-selective linear-phase bandpass filters of the distributed, digital, or switched-capacitor type. The main feature of these new function is its ability to yield ideal transmission together with linear phase and constant delay at a set of prescribed frequencies distributed over the passband. An efficient algorithm is described for determining the optimum locations of these frequency points, in order to realize an equiripple passband loss. The stability of the resulting transfer function is always guaranteed. Illustrative examples are given