Reflector Antennas

antennas in which the phenomenon of mirror reflection from curvilinear metal surfaces (mirrors) is used to focus high-frequency electromagnetic energy. The reflector is a great deal larger than the wavelength. The main modifications of reflector antennas are determined by the number of reflectors: one-, two- and three-reflector antennas exist. Structurally, reflector antennas are metallic or metal-plated surfaces of various shapes. To reduce the weight of the mirrors and the wind pressure (sail factor) on their surface, the mirrors often are made of a wire grid or parallel plates, as well as of perforated sheet metal, rather than continuous material. Types of reflector antennas used include parabolic antennas, Cassegrain antennas, parabolic horn antennas, spherical antennas, periscopic antennas, and aplanatic reflector antennas.