Realization of resistively terminated two-variable lossless ladder networks

A major problem to be solved in the design of two-dimensional wave digital filters is the realization of a resistively terminated two-variable analog reference network satisfying the prescribed specifications. This paper presents a simple procedure for the realization of a two-variable doubly (resistively) terminated low-pass ladder network with all transmission zeros at and (in the complex biplane). The transfer function of the realized network will not have nonessential singularities of first or second kind in the closed right half of planes including infinite distant points, so the analog network realized can be converted into a 2-D wave digital filter with guaranteed stability. The realization is obtained using the two-variable approach.