A full-wave analysis for determining the resonant frequency, quality factor and far-zone radiation patterns of a circular disk and annular ring microstrip patches, printed on a uniaxial anisotropic substrate is presented. Green's functions of the structure are determined in Hankel transform domain (HTD) using Hertz potential vectors. Galerkin's method, together with parsval's relation in Hankel transform domain is then applied to compute the resonant frequency and quality factor. The far-zone radiation patterns are expressed in terms of Hankel transforms of the tangential fields on the substrate. Wave equation is solved in cylindrical coordinates for the structure to estimate the basis function. The numerical results show that there are substantial deviations in calculated resonant frequency and quality factor when substrate dielectric anisotropy is considered. Furthermore, significant variations are seen in the radiation patterns of the structures due to substrate anisotropy. The variations of resonant frequency, quality factor and radiation patterns of the structure, with respect to anisotropy ratio of the substrate, for several values of substrate thickness and patch radius are presented.
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