Variable beamwidth dual reflector antenna

The growth of remote sensing by an airborne platform and the use of satellite communication from elliptical orbits indicate the need for a reflector antenna where the beamwidth of the main radiation pattern can be varied dynamically. The requirement is to make the radiated beam spot diameter independent of the antenna platform height and the scan angle. There are various other applications at microwave and millimetre wavelengths where a uniform footprint or precise changes in the beam spot diameter are required, for example, metrology from satellites, fire control radars and military communications. This paper describes a variable beamwidth dual reflector antenna which fulfils their specification. Parametric studies and an experimental verification of the concept are performed