NUMERICAL ANALYSIS OF PERIODIC PLANAR STRUCTURES ON UNIAXIAL SUBSTRATES FOR MINIATURIZATION PURPOSES

Abstract

In this paper, a numerical analysis of a periodic planar structure using a uniaxial substrate is shown. The paper means to explore the possibility to use non-conventional substrate to reduce the size of planar radiating structure. The encouraging numerical results set the ground for a further experimental analysis. The presented results can be applied easily to the design of planar antennas, arrays and Frequency Selective Surfaces (FSS). A FSS resonating at 20.75 GHz has been analyzed. Pyrolytic boron nitrite (PBN), which has an anisotropic dielectric with a relative electric permittivity represented by a diagonal tensor, is adopted as the substrate of the designed FSS to achieve the size reduction while maintaining the FSS performance. The design is then compared with the one that uses isotropic substrate (i.e., RO4003). Comparison shows that the introduction of such a non-conventional medium allows the patch size to be reduced approximately by 20% while maintaining almost the same electromagnetic performance. Issues about size reduction and frequency shifting are further presented and discussed in the paper.