Dual-Band Cavity-Backed Ka-Band Antenna for Satellite Communication

In this paper we present the analysis and design of a dual band cavity baked antenna element for ka band satellite communication systems. This element represent the basic block for a planar antenna array to be used for on-move satellite system. The proposed cavity backed antenna is composed of 3x3 circular apertures on a conducting plane. These circular apertures are fed by a rectangular cavity. This cavity is fed through a square aperture located at the bottom side. This aperture is fed by two cascaded rectangular cavities corresponding to the lower and upper frequency bands. These cascaded cavities are fed by two orthogonal rectangular waveguide sections. These orthogonal waveguide arrangement introduces orthogonal polarizations for the upper and lower frequency bands. The analysis of the proposed cavity backed antenna is developed by using HFSS and verified by using CST. A 2x2 array of this cavity backed element is also investigated. It is found that the closed cavity configuration reduces the mutual coupling between the nearby elements.