Broadband Approximation of Radiation Patterns for Doubly Curved Reflector Antennas [Antenna Designer´s Notebook]

Avery simple broadband approximation of the radiation patterns for shaped-beam reflector antennas with a primary feed (rectangular horn), producing cosine amplitude and uniform phase aperture distributions, is presented. Typical values, beamwidth changes, sidelobe levels, and aperture efficiencies are given for frequency changes up to approximately three times the operating frequency. A comparison of the approximated and measured patterns of doubly curved reflector antennas shows that the given approximation can be reliably used for analyses of pattern changes due to very broad frequency changes. This is very valuable for electromagnetic compatibility analyses, both from the electromagnetic interference and susceptibility points of view.