DESIGN OF 2-D RECURSIVE FILTERS WITH ASYMMETRIC HALF-PLANE LATTICE MODELING

A method, based on 2-D asymmetric half-plane lattice parameters, for the design of two dimensional (2-D) recursive digital filters is presented. The design procedure calculates the lattice parameter factors from the prescribed frequency characteristics. The order of the design is controlled by an a priori error criterion, corresponding to the minimum mean squared error between two successive stages. The stability of the resulting filter is determined at each successive lattice stage from the computed 2-D reflection factors. The capabilities of the proposed approach are demonstrated by the design of a fan filter and circularly symmetric lowpass filter. The computer time for their design is of the order of seconds for both filters.