Direct design of bandpass wave digital ladder filters

The paper extends further the wave digital filter (WDF) design problem. It presents a direct design method for bandpass wave digital filters having simple ladder structures for which the amplitude function has the same features of Chebyshev response. This is relying on the proper formulation of the transmission function in the reference domain such that the transmission zeros occur at the origin and infinity. The transmission function is designed using interpolation methods combined with the Remez-exchange algorithm. Consequently, it is synthesized by extracting the poles at the origin and infinity from the successive resulting impedance and admittance functions. Finally the wave digital realization is obtained.