Radiation characteristics of cavity backed aperture antennas in finite ground plane using the hybrid FEM/MoM technique and geometrical theory of diffraction

Author

Reddy, C.J. ; Deshpande, M.D. ; Cockrell, C.R. ; Beck, F.B.

Author_Institution

NASA Langley Res. Center, Hampton, VA, USA

Volume

44

Issue

10

fYear

1996

fDate

10/1/1996 12:00:00 AM

Firstpage

1327

Lastpage

1333

Abstract

A technique using the hybrid finite element method (FEM)/method of moments (MoM) and geometrical theory of diffraction (GTD) is presented to analyze the radiation characteristics of cavity fed aperture antennas in a finite ground plane. The cavity which excites the aperture is assumed to be fed by a cylindrical transmission line. The electromagnetic (EM) fields inside the cavity are obtained using finite element method (FEM). The EM fields and their normal derivatives required for FEM solution are obtained using: (1) the modal expansion in the feed region and (2) the MoM for the radiating aperture region (assuming an infinite ground plane). The finiteness of the ground plane is taken into account using GTD. The input admittance of open-ended circular, rectangular, and coaxial line radiating into free space through an infinite ground plane are computed and compared with earlier published results. Radiation characteristics of a coaxial cavity-fed circular aperture in a finite rectangular ground plane are verified with experimental results

Keywords

antenna feeds; antenna radiation patterns; aperture antennas; electric admittance; electromagnetic field theory; finite element analysis; geometrical theory of diffraction; method of moments; FEM; MoM technique; cavity backed aperture antennas; coaxial cavity-fed circular aperture; coaxial line; cylindrical transmission line; electromagnetic fields; finite element method; finite ground plane; geometrical theory of diffraction; input admittance; method of moments; modal expansion; open-ended circular line; radiating aperture region; radiation characteristics; rectangular line; Antenna theory; Aperture antennas; Coaxial components; Electromagnetic fields; Electromagnetic radiation; Feeds; Finite element methods; Moment methods; Physical theory of diffraction; Transmission line theory;

fLanguage

English

Journal_Title

Antennas and Propagation, IEEE Transactions on

Publisher

ieee

ISSN

0018-926X

Type

jour

DOI

10.1109/8.537326

Filename

537326