Electromagnetic Band Gap Materials Simplify the Structure of Dual Polarized Satellite Communications Antennas

The dual polarized reflector antenna used for satellite communications consists of two reflectors; one reflector is solid, the other consists of metal grid. The structure is complicated and the bandwidth is narrow. This antenna structure can be simplified by removing the metal grid and using the solid reflector together with a thin electromagnetic band gap material pasted to the surface of the reflector. The reflector works as a ground plane for the electromagnetic band gap material. The material is of the mushroom-like type. The material reflects the two orthogonal linearly polarized plane waves incident upon it without any change of polarization after reflection. A simple procedure for the design of the electromagnetic band gap material is developed. The antenna is wideband and the bandwidth is defined in advance. The dependence of the material dimensions upon the bandwidth is studied.