Design and analysis of a center-fed quad-band ring-focus reflector antenna

Small (4-9´) light-weight, transportable, multi-band, SATCOM reflector antennas are in high demand for military and other applications. Offset prime-focus and dual-reflector designs are optimum front a performance standpoint for these reflector sizes, but structural and tolerance constraints, drive till! design to a center-fed type. One method of realizing a form factor for a transportable center-fed multi-band reflector antenna is to use a single main-reflector/multiple-feed approach. This paper addresses it quad-band ring-focus reflector design utilizing a single main aperture approximately eight feet in diameter with four replacable independent feed/RF chains. The antenna design is derived numerically utilizing the BOR MoM, PO, and GO shaping techniques, and has been constructed and tested. Representative comparisons of measured versus predicted pattern data are presented.