In this paper we propose a class of 2D circularly-symmetric filter banks based on a 1D IIR Gaussian prototype. We approach two cases, namely dyadic and uniform filter banks. The Gaussian prototype is obtained using an efficient rational approximation, namely the Chebyshev-Padé approximation. Then, using a frequency transformation, the corresponding 2D filters with circular symmetry are derived....

This paper presents the effect on circular polarization of multilayer circular annular ring patch (CARP). A CARP have been fabricated on FR4 substrate of dielectric constant 4.2 and thickness 1.52mm. Experimental resonant frequency impedance bandwidth and Axial ratio of simple CARP, covered CARP, spaced dielectric CARP and CARP with two superstrates have been measured and simulated using full w...