Amplitude aperture-distribution control in displaced-axis two-reflector antennas

Author

Popov, Alexandre P. ; Milligan, Tom

Author_Institution

Univ. of Technol., Lae, Papua New Guinea

Volume

39

Issue

6

fYear

1997

fDate

12/1/1997 12:00:00 AM

Firstpage

58

Lastpage

63

Abstract

A design method for improving the efficiency and reduction of sidelobes in displaced-axis two-reflector antennas is presented. The method is based on an analysis of the geometrical-optics field transformation in the displaced-axis two-reflector arrangement. The principal difference of the displaced-axis antenna from the Cassegrain/Gregory two-reflector antenna is pointed out. While decreasing the level of illumination of the subreflector edge in the Cassegrain/Gregory antenna leads to decreasing the sidelobe levels, and, respectively, the efficiency of the antenna system, in the displaced-axis antenna, decreasing the level of illumination of the subreflector leads to an increased level of sidelobes and an essentially nonuniform amplitude distribution in the aperture. The aperture-amplitude-distribution dependence of the illumination level of the subreflector edge in displaced-axis antennas is much stronger than in Cassegrain/Gregory antennas

Keywords

antenna radiation patterns; geometrical optics; interference suppression; microwave antennas; reflector antennas; 8.4 GHz; amplitude aperture-distribution control; design method; displaced-axis two-reflector antennas; efficiency; geometrical-optics field transformation; illumination; sidelobes; subreflector edge; Antenna feeds; Antennas and propagation; Aperture antennas; Communication system control; Costs; Displacement control; Fabrication; Geometry; Reflector antennas; Shape control;

fLanguage

English

Journal_Title

Antennas and Propagation Magazine, IEEE

Publisher

ieee

ISSN

1045-9243

Type

jour

DOI

10.1109/74.646802

Filename

646802