The triply-folded horn reflector: A compact ground station antenna design for satellite communications

An antenna suitable for ground stations of satellite communications systems is described. The antenna has very good low-noise properties, high aperture efficiency, and excellent broadband characteristics. It can be operated without a radome and allows the location of all communications and tracking equipment in a stationary room on the ground. Called the “triply-folded horn-reflector antenna,” it is derived from the well-known conical horn-reflector antenna by folding the horn three times to bring its apex into a stationary position on the ground. Plane reflectors are used in the folding process and the propagation in the antenna is based on the principles of geometrical optics. The paper describes electrical tests on an antenna model at frequencies of 60 and 11 gc and presents results of hydrodynamic tests which were performed to study the behavior of the antenna in high wind.