DocumentCode :
1028927
Title :
Equivalence of surface current and aperture field integrations for reflector antennas
Author :
Yaghjian, Arthur D.
Author_Institution :
Rome Air Development Center, Hanscom AFB, MA, USA
Volume :
32
Issue :
12
fYear :
1984
fDate :
12/1/1984 12:00:00 AM
Firstpage :
1355
Lastpage :
1358
Abstract :
The "extinction theorem" is used to prove that the fields of reflector antennas determined by integration of the current on the illuminated surface of the reflector are identical to the fields determined by aperture field integration with the Kottler-Franz formulas over any surface S_{a} that caps the reflector. As a corollary to this equivalence theorem, the fields predicted by integration of the physical optics (PO) surface currents and the Kottler-Franz integration of the geometrical optics (GO) aperture fields on S_{a} agree to within the locally plane-wave approximation inherent in PO and GO. Moreover, within the region of accuracy of the fields predicted by PO current or GO aperture field integration, the far fields predicted by the Kottler-Franz aperture integration are closely approximated by the far fields obtained from aperture integration of the tangential electric or magnetic field alone. In particular, discrepancies in symmetry between the far fields of offset reflector antennas obtained from PO current and GO aperture field integrations disappear when the aperture of integration is chosen to cap (or nearly cap) the reflector.
Keywords :
Reflector antennas; Antenna theory; Aperture antennas; Equations; Feeds; Geometrical optics; Image analysis; Magnetic analysis; Magnetic fields; Physical optics; Reflector antennas;
fLanguage :
English
Journal_Title :
Antennas and Propagation, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-926X
Type :
jour
DOI :
10.1109/TAP.1984.1143261
Filename :
1143261
Link To Document :
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