THE OPTIMAL AND STRAIGHTFORWARD DESIGN OF BANDPASS WAVE DIGITAL LATTICE FILTERS WITH ARBITRARY LOSS SPECIFICATIONS

An efficient, simple and reliable design method is introduced for band pass wave digital lattice filters exhibiting arbitrary loss responses. The main feature of this method is that the approximation is straight forward. Thus it is carried out without the need to apply frequency tr ansformation techniques. The method relies on employing the relationsh ip between the amplitude and the two branch phase functions of the fil ter. As a consequence, the whole problem reduces finally to constructi ng a polynomial specified by its phase. The generation of this polynom ial is achieved through the use of interpolation recurrence formulae. By factorizing this polynomial into its Hurwitz and non-Hurwitz parts, the two branch allpass functions are determined and realized. (C) 199 7 by John Wiley & Sons, Ltd.