Title :
Crossed square loop antenna
Author :
Sharshar, A.A. ; Zainud-Deen, S.H. ; El-Halafawy, S.M.
Author_Institution :
Fac. of Electron. Eng., Menouf, Egypt
Abstract :
The characteristics of the crossed loop structure have been investigated as an antenna and as an antenna and as a scatterer. The problem is formulated in terms of surface integral equation based on the reaction concept. The unknown is the surface current which can be calculated using the method of moments. In the antenna model one of the two loops is fed at the center point along one of its sides, by an impressed voltage source. The other loop is shorted and acts as a parasitic element. The effect of the skew angle and the dimension of each loop on the input impedance, current distribution and the radiated field is considered. In the scatterer model, the two crossed loops are loaded by a reactive load and they are illuminated by a linearly polarized incident plane wave. The loop induced current and backscattered field have been determined. The behaviour of the current at the loading points is extensively examined. The usefulness of the crossed loop structures in radio direction finding has been emphasized. It is found that the direction of the incident wave can be determined. This can easily be calculated from the current ratio at the loading points.
Keywords :
antenna feeds; antenna radiation patterns; backscatter; current distribution; electric impedance; electromagnetic wave polarisation; electromagnetic wave scattering; integral equations; loop antennas; method of moments; radio direction-finding; antenna model; backscattered field; center point; crossed square loop antenna; current distribution; current ratio; impressed voltage source; input impedance; linearly polarized incident plane wave; loop dimension; loop induced current; method of moments; parasitic element; radiated field; radio direction finding; reactive loaded antenna; scatterer model; skew angle; surface current; surface integral equation; Broadband antennas; Directive antennas; Geophysics computing; Impedance; Integral equations; Moment methods; Polarization; Receiving antennas; Scattering; Voltage;
Conference_Titel :
Antennas and Propagation Society International Symposium, 1997. IEEE., 1997 Digest
Conference_Location :
Montreal, Quebec, Canada
Print_ISBN :
0-7803-4178-3
DOI :
10.1109/APS.1997.630137