Title :
Waveguide matching crossed-slot
Author :
Hirano, T. ; Hirokawa, J. ; Ando, M.
Author_Institution :
Fac. of Eng., Tokyo Inst. of Technol., Japan
fDate :
6/10/2003 12:00:00 AM
Abstract :
A matching crossed-slot, which is accommodated at the shorted end of a waveguide crossed-slot array and radiates all the residual power with circular polarisation in an array beam direction, is analysed and designed by the method of moments (MoM). The eigenmode functions for a crossed-slot derived numerically by the edge-based finite element method (FEM) are utilised as the basis functions in the MoM. The mechanism of circular polarisation is interpreted in terms of two modes each radiating linear polarisation. A matching crossed-slot is designed and tested at 3.6 GHz. The measured reflection is suppressed below -15 dB over a 5.6% bandwidth from 3.5 GHz to 3.7 GHz. The calculated and measured axial ratios in a direction of 50 degrees are 0.32 dB and 1.5 dB, respectively.
Keywords :
eigenvalues and eigenfunctions; electromagnetic wave polarisation; electromagnetic wave reflection; finite element analysis; impedance matching; method of moments; microwave antenna arrays; slot antenna arrays; 3.5 to 3.7 GHz; 3.6 GHz; FEM; MoM; SHF; array beam direction; axial ratios; bandwidth; basis functions; circular polarisation; edge-based finite element method; eigenmode functions; linear polarisation; measured reflection; method of moments; shorted end; waveguide crossed-slot array; waveguide matching crossed-slot;
Journal_Title :
Microwaves, Antennas and Propagation, IEE Proceedings
DOI :
10.1049/ip-map:20030471
