Radiation characteristics of cylindrical microstrip patch antennas using metallic EBG surfaces as superstrates

One-dimensional antenna arrays with complex feeding mechanisms have been commonly used to produce high directivity in the elevation plane and wide horizontal beams. However, cylindrical metallo-dielectric electromagnetic band gap (MEBG) surfaces have been presented in the past as superstrates for enhancing the directivity of a single dipole in the elevation plane, while maintaining wide horizontal beams. The MEBGs behave as partially reflecting surfaces (PRSs) and form a resonant cavity with the cylindrical metallic ground. At the cavity resonant frequency maximum directivity is obtained. In this paper, we present the application of a cylindrical MEBG-PRS array to the design of an omni-directional cylindrical patch antenna which has been previously reported. In addition, we propose a design that further improves the omni-directionality of the structure in the H-plane, while achieving highly directive patterns in the elevation plane.