Achieving Antenna Isolation within Subwavelength Directive Cavity

Abstract

Antenna arrays embedded within a compact Fabry-Perot cavity have to be optimized to limit interactions between elementary antennas. In this article, we propose to use a superstrate metamaterial to design a highly isolated antenna array. This superstrate is based on the microstrip technology. It is made of an inductive and a capacitive grid respectively etched on the top and the bottom of epoxy plate. Metallic vias are then inserted through the superstrate to connect the two etched grids. This superstrate combined with a metallic ground plane leads to the design of a subwavelength cavity. The proposed cavity allows a significant antenna profile reduction and performance enhancement. More importantly, this structure provides a high isolation for an antenna array.