A compact high gain antenna for small satellite applications

The development of a circularly-polarized compact high-gain antenna to be used for the European Student Earth Orbiter small satellite mission is described. The antenna is realized stacking two coaxial shorted annular patches and placing the top one at half a wavelength from the lower one. At variance of other similar configurations proposed in the past, the one presented in this paper has several important features which can be extremely useful for application in the space environment. In particular, it can be easily fabricated employing suspended technology and its radiation characteristics are to some extent controllable by opportunely varying the geometry. In the following, a straightforward design procedure will be presented detailing the criteria to optimize top and bottom radiating elements. Both numerical and measured results will show that the proposed design satisfies the specifications and presents characteristics comparable to other larger and heavier solutions usually more difficult to design. Specifically, it will be shown that with this configuration it is possible to obtain gain values higher than 12 dB using ground plane of moderate size and that a further improvement up to 15dB can be obtained employing larger ground planes.