TY - JOUR
T1 - Effect of aperture feed and reflector configuration on the time- and frequency domain radiation patterns of reflector impulse radiating antennas
AU - Tyo, J. Scott
AU - Farr, Everett G.
AU - Schoenberg, Jon S.H.
AU - Bowen, Leland H.
AU - Altgilbers, Larry L.
N1 - Funding Information:
Manuscript received February 27, 2003; revised June 11, 2003. This work was supported by the U.S. Army Space and Missile Defense Command. J. S. Tyo is with the Electrical Engineering and Computer Engineering Department, University of New Mexico, Albuquerque, NM 87131 USA (e-mail: [email protected]). E. G. Farr and L. H. Bowen are with Farr Research, Incorporated, Albuquerque, NM 87123 USA (e-mail: [email protected]; [email protected]. J. S. H. Schoenberg was with the Air Force Research Lab/DEHP, Kirtland AFB, NM 87117 USA. He is now with the U.S. Department of Defense (e-mail: [email protected]). L. L. Altgilbers is with the U.S. Army Space and Missile Defense Command, Redstone Arsenal, AL 35807 USA. Digital Object Identifier 10.1109/TAP.2004.830256 Fig. 1. Schematic of the IRA being studied. (a) Side view with focal length and diameter. (b) Aperture plane after stereographic projection.
PY - 2004
Y1 - 2004
N2 - The prompt off-boresight radiation from an arbitrary reflector impulse radiating antenna (IRA) is considered in both the time and frequency domains using a time-domain physical optics formalism. The theory is used to compare the performance between reflector IRAs with common transverse electromagnetic feed configurations that have been designed to maximize the boresight fields. It is found that moving the feed arms of reflector IRAs toward the vertical helps to reduce sidelobe levels, as reflector IRAs with their feed arms oriented at 60° from the horizontal have sidelobes that are 4-5 dB lower in the H plane and 1-2 dB lower in the E plane than more traditional reflector IRAs with feed arms oriented at 45°. The lower sidelobes are accompanied by a higher peak gain, albeit with a wider beamwidth. There are corresponding significant differences in the time domain waveforms that result. The theory is verified by comparison with experimental data from a half IRA with feed arms at 45°. The peak fields, pulse widths, and overall waveform shapes agree well between theory and experiment, though there are temporal asymmetries in the measured data that are not predicted by the theory.
AB - The prompt off-boresight radiation from an arbitrary reflector impulse radiating antenna (IRA) is considered in both the time and frequency domains using a time-domain physical optics formalism. The theory is used to compare the performance between reflector IRAs with common transverse electromagnetic feed configurations that have been designed to maximize the boresight fields. It is found that moving the feed arms of reflector IRAs toward the vertical helps to reduce sidelobe levels, as reflector IRAs with their feed arms oriented at 60° from the horizontal have sidelobes that are 4-5 dB lower in the H plane and 1-2 dB lower in the E plane than more traditional reflector IRAs with feed arms oriented at 45°. The lower sidelobes are accompanied by a higher peak gain, albeit with a wider beamwidth. There are corresponding significant differences in the time domain waveforms that result. The theory is verified by comparison with experimental data from a half IRA with feed arms at 45°. The peak fields, pulse widths, and overall waveform shapes agree well between theory and experiment, though there are temporal asymmetries in the measured data that are not predicted by the theory.
UR - http://www.scopus.com/inward/record.url?scp=3843143948&partnerID=8YFLogxK
U2 - 10.1109/TAP.2004.830256
DO - 10.1109/TAP.2004.830256
M3 - Article
AN - SCOPUS:3843143948
SN - 0018-926X
VL - 52
SP - 1767
EP - 1776
JO - IEEE Transactions on Antennas and Propagation
JF - IEEE Transactions on Antennas and Propagation
IS - 7
ER -