Maximal Bandwidth of an Archimedean Spiral Antenna Above a Reflector

Author

Djoma, Christopher ; Jousset, Michel ; Lepage, Anne Claire ; Mallegol, Stephane ; Renard, Christian ; Begaud, Xavier

Author_Institution

Commun. & Electron. Dept., Telecom ParisTech, Paris, France

Volume

13

fYear

2014

fDate

2014

Firstpage

333

Lastpage

336

Abstract

In this letter, the maximal achievable bandwidth of an Archimedean spiral antenna above a reflector is investigated. This bandwidth is defined by the frequency range where the gain in the broadside direction is higher than the case without a reflector. To determine this theoretical bandwidth, we propose an analysis consisting in replacing the Archimedean spiral antenna by a bidirectional elliptical plane-waves source above an infinite reflector. Thanks to this approximation, it is possible to evaluate this bandwidth with a simple analytical expression, which is defined by constructive interferences between two plane waves. The maximal bandwidth obtained from this formula is equal to 5:1 for a metallic reflector. Simulations and measurements are then presented in order to confirm this result.

Keywords

approximation theory; radiofrequency interference; reflector antennas; spiral antennas; Archimedean spiral antenna; approximation; bidirectional elliptical plane-waves source; broadside direction; constructive interferences; infinite reflector; maximal achievable bandwidth; metallic reflector; plane waves; Bandwidth; Bidirectional control; Broadband antennas; Electric fields; Reflector antennas; Spirals; Archimedean spiral antenna; artificial magnetic conductor (AMC); perfect electric conductor (PEC); perfect magnetic conductor (PMC); wideband reflector;

fLanguage

English

Journal_Title

Antennas and Wireless Propagation Letters, IEEE

Publisher

ieee

ISSN

1536-1225

Type

jour

DOI

10.1109/LAWP.2014.2303858

Filename

6729034