TRANSVERSE ANTENNA FEEDS
Abstract
This study of the transverse focal region of a spherical reflector includes theoretical analyses centered on geometric optics, on vector polarization and on diffraction integrals of physical optics and their evaluation by the method of stationary phase. The results of the numerical evaluation of the focal region field for an incoming wave of uniform amplitude and phase agree with experimental measurements taken on a 10-ft. spherical reflector operating at 24 Gc. An annular step disc feed was designed using the calculated field as a basis. This transverse feed is designed to correct for spherical aberration over an included angle of the sphere of 120 degrees. The measured secondary patterns show agreement with the theory in the region of the main lobe. The disagreement in the area of the side lobes is attributed partly to blockage introduced by the feed horn support and partly to incomplete control of illumination amplitude. Methods are described for minimizing complexity due to polarization and for determining feed distributions required for non-uniform amplitude aperture distributions. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1966
- Accession Number
- AD0628500
Entities
People
- David F. Bowman