An Optimum Meshing to Compute The Radiation Integrals of Reflector Antennas by FFT Method

The rapid calculation of the far-field radiation fields of a reflector antenna by optimum meshing size is reported. The reflector can be the intersection of a cone with any surface of revolution or an offset sector of any surface of revolution. The feed is assumed to be linearly polarized and located in a desired place in front of the reflector. The reflector is analyzed by Geometrical Optics (GO) theory and Physical Optics (PO) approximation. Then, radiation fields are calculated by aperture distribution method in which the radiation integrals computed by FFT method. The maximum mesh size of the aperture plane of the reflector should be less than one wavelength. The program based on MATLAB can analyze and simulate all shaped reflector antennas with large dimensions in regard to the wavelength. The presented numerical method can be applied to all the shaped reflector antennas fed by arbitrary feeds to simulate radiation characteristics fast and accurately.