A Stacked Ring-patch Artificial Substrate to Improve the Antenna Performance

In this paper, a stacked ring-patch two layer planar artificial substrate is analyzed numerically and is shown to possess the properties of a high impedance surfaces (HIS). Its properties are evaluated by investigating the surface wave propagation and plane wave reflection characteristics. Its application to reduce the mutual coupling of microstrip antennas and to improve the radiation pattern are investigated by simulation tool CST microwave studio. Experimental measurements using a pair of monopoles are used to confirm the surface waves suppression band. One of the main advantages of the proposed geometry is that it is simple and planar in nature, without the need for any via connections across dielectric layers and thus can be realized by planar technologies. Another advantage is that it exhibits over lapped surface wave suppression and in-phase reflection bands. Also it can be scalable to operate in different frequency range.