An investigation of circular patch antenna on pin-bed type RIS

This paper presents analysis of circular microstrip patch antenna placed over a thin grounded pin bed type reactive impedance surface (RIS). Effect of the variation in the height of the pins on the resonant frequency and the radiation properties of antenna have been studied. 3D EM simulation tools based on finite element method (Ansoft's HFSS) and finite integration technique (CST Microwave Studio) are used to model the structure. Magnetic field distribution within the pin-bed substrate has also been studied. 26% compactness has been achieved with the pin bed structure maintaining the gain within an appreciable limit.