Diffraction analysis of line feeds for spherical reflectors

Author

Kildal, Per-Simon

Author_Institution

ELAB-RUNIT, Norwegian Inst. of Technol., Trondheim, Norway

Volume

38

Issue

9

fYear

1990

fDate

9/1/1990 12:00:00 AM

Firstpage

1366

Lastpage

1373

Abstract

The diffraction limitations of the line feeds for spherical reflector antennas are analyzed by means of an asymptotic transition region theory (TRT). It is shown that diffraction from the ends of the line feed causes a broad 6-dB-deep central dip in the aperture field of the reflector. The corresponding reduction in aperture efficiency and increase in spillover are also calculated by means of the TRT. The accuracy of the theory is checked by numerical evaluations of the array sum expression for the radiation field and of the secondary aperture-field and spillover integrals. The results are applicable to the line feeds of the spherical reflector antenna of the Arecibo Observatory

Keywords

antenna feeders; antenna radiation patterns; electromagnetic wave diffraction; reflector antennas; Arecibo Observatory; aperture efficiency; aperture field; asymptotic transition region theory; diffraction limitations; line feeds; radiation field; reflector antennas; spherical reflectors; spillover; Antenna feeds; Antenna radiation patterns; Antenna theory; Apertures; Optical diffraction; Optical losses; Optical waveguides; Phased arrays; Reflector antennas; Testing;

fLanguage

English

Journal_Title

Antennas and Propagation, IEEE Transactions on

Publisher

ieee

ISSN

0018-926X

Type

jour

DOI

10.1109/8.56987

Filename

56987