Application of spherical wave expansions to reflector antennas using truncated field data
Abstract
The electromagnetic field radiated by paraboloidal and hyperboloidal reflector antennas excited by an azimuthally independent, linearly polarized source is considered. The electromagnetic field is sampled on a spherical surface in order to numerically generate a set of spherical wave mode coefficients which, in turn, are used to compute antenna patterns. Patterns are produced in the near and farfield regions based on both full and partial, or truncated, near and farfield data as a function of the antenna parameters and the truncation angle location. The similarity of the patterns obtained from truncated field data to the untruncated patterns is found to depend on the pattern level at the truncation point, the location of the truncation point, the antenna parameters, and the radial distance between the spherical surfaces on which the electromagnetic field is sampled and produced.
 Publication:

IEEE Transactions on Antennas and Propagation
 Pub Date:
 May 1991
 DOI:
 10.1109/8.81492
 Bibcode:
 1991ITAP...39..639Y
 Keywords:

 Antenna Radiation Patterns;
 Parabolic Antennas;
 Parabolic Reflectors;
 Reflector Antennas;
 Spherical Waves;
 Far Fields;
 Hyperbolas;
 Near Fields;
 Communications and Radar