Analysis and Design of Elementary Blinders for Large Horn Reflector Antennas

Abstract

An analysis of E-plane (transverse) radiation from horn reflector antennas for horizontal (transverse) polarization is presented. This analysis was based on Geometrical Theory of Diffraction with modifications to account for (i) finite edges, (ii) grazing incident wave, and (iii) aperture illumination. Once proven valid for our purposes, the analysis was extended to permit blinders to be added to the antenna. Experimental and theoretical studies of single edge blinders have shown them to move the azimuth location of undesirable high sidelobes but not substantially reduce the sidelobe level. A half blinder, however, was shown to reduce the undesired 90-degree sidelobe to — 62 dB, an 8-dB reduction. Simultaneously, sidelobe levels are below — 62 dB for azimuths between 35 degrees and 180 degrees at both 3.74 and 6.325 GHz. Theoretical predictions indicate it is broadband at 4, 6, and 11 GHz. The half blinder also has excellent mechanical features.