Reflector Antennas

In transmission, a reflector antenna concentrates energy received from another antenna, called a feed, into a narrow beam of radiation. In transmission, a reflector antenna concentrates energy received from another antenna, called a feed, into a narrow beam of radiation. In reception, the reflector re-directs the impinging field and concentrates it in a smaller volume, called the focal region, where it can be collected. This chapter describes the properties of reflector antennas in common use, including the paraboloid the Cassegrain, and spheroid geometries as well as some offset counterparts. It also discusses radiation from a paraboloidal reflector and reflector antenna efficiency. The chapter describes the shaping of the reflector surface in order to achieve a prescribed radiation pattern. The first technique is based on geometrical optics, the second is based on computer numerical optimization techniques, and the last employs an algorithm specially developed for reflector shaping.