DocumentCode :
1310262
Title :
Modulated Arm Width (MAW) Spiral: Theory, Modeling, Design and Measurements
Author :
Kefauver, W. Neill ; Cencich, Thomas P. ; Filipovic, Dejan S.
Author_Institution :
Lockheed Martin, Waterton, CO, USA
Volume :
58
Issue :
11
fYear :
2010
Firstpage :
3515
Lastpage :
3523
Abstract :
The design and performance is discussed of equiangular four-arm modulated arm width (MAW) spiral antennas. Effects of expansion factor, modulation ratio, termination and feed point region on cross-polarization, pattern symmetry, gain, and impedance for both forward and reverse mode 1 operation are studied. The bandstop region is characterized using the transmission line theory and full-wave modeling. Three composite ideal beamforming measurements are developed and are shown to be in excellent agreement with theoretical predictions. Obtained results indicate that the expansion factor should be less than 1.5 and the modulation ratio needs to be higher than 4 to achieve high purity radiation patterns in both modes of operation. Beamformer design, effects of the dielectric loading, and non-ideal cavity-backing are not discussed.
Keywords :
antenna feeds; antenna radiation patterns; antenna theory; log periodic antennas; spiral antennas; MAW spiral antenna; antenna radiation patterns; bandstop region; beamforming measurements; cross-polarization; dielectric loading; equiangular four-arm modulated arm width spiral antennas; expansion factor effect; feed point region; full-wave modeling; log periodic antennas; modulation ratio; nonideal cavity-backing; pattern symmetry; transmission line theory; Antenna measurements; Geometry; Impedance; Modulation; Spectral analysis; Spirals; Log periodic antennas; multimode transmission lines; spectral domain analysis; spiral antennas;
fLanguage :
English
Journal_Title :
Antennas and Propagation, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-926X
Type :
jour
DOI :
10.1109/TAP.2010.2071357
Filename :
5560752
Link To Document :
بازگشت