Offset-paraboloid geometry: relations for practical use

Offset-paraboloidal reflector antennas are used for satellite-communication systems, because they provide low sidelobes and high eficiency. The analysis of the radiation characteristics for the reflector antenna have been studied, with the geometric parameters related to focal length. But we sometimes need to convert the geometrical parameters of the offset-paraboloidal reflector to dimensions relative to the plane of the rim, especially during manufacture. The focal length and geometric parameters are also formulated from the easily measured parameters of the reflector, such as length, width, and depth.