Symmetry in the frequency response of two-dimensional (/spl gamma//sub 1/, /spl gamma//sub 2/) complex plane discrete-time systems

This paper presents the constraints on two-dimensional /spl gamma/-domain polynomials so that they possess various types of symmetries in their magnitude functions. Refering to a parameter (/spl Delta/), it is concluded that new symmetry conditions derived in /spl gamma/-plane converge to those of 2-D continuous-time systems as /spl Delta/ tends to zero. For analog sampled-data systems, /spl Delta/ can be treated as a sampling period, otherwise it is simply treated as a design parameter.