A technique is presented for improving the performance of low-profile, circularly polarized (CP) radiating-line antennas. The essential elements of the technique pertain to establishing a single traveling wave on an annular sector of conducting strip that is positioned parallel and close to a large conducting surface. The antenna is named the annular sector, radiating-line (ANSERLIN) antenna. Using this technique, the impedance bandwidth becomes so large that it no longer has any bearing on the operating bandwidth. Instead, the pattern shape and axial ratio become the factors that limit the bandwidth. Both senses of circular polarization can be transmitted or received from the same structure. Experimental results for two-port ANSERLIN antennas are presented. The method of exciting a traveling wave on the annular sector is discussed. Design parameters are given for an antenna that will produce a broadside axial ratio that is less than 0.5 dB at a specified frequency


Electrical and Computer Engineering

Keywords and Phrases

ANSERLIN; Bandwidth; Broad-Band; Circularly Polarized Antenna; Dielectric Loading; Dielectric-Loaded Antennas; Radiating-Line Antennas; Polarization; Bandwidth; Impedance; Feeds; Conductors; Frequency; Microstrip Antennas; Spirals; Vehicles; Slot Antennas

International Standard Serial Number (ISSN)

0018-926X; 1558-2221

Document Type

Article - Journal

Document Version

Final Version

File Type





© 1989 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 Mar 1989