A monofilar spiral antenna excited through a helical wire

Author

Nakano, Hisamatsu ; Okabe, Yosuke ; Mimaki, Hiroaki ; Yamauchi, Junji

Author_Institution

Fac. of Eng., Hosei Univ., Tokyo, Japan

Volume

51

Issue

3

fYear

2003

fDate

3/1/2003 12:00:00 AM

Firstpage

661

Lastpage

664

Abstract

The radiation characteristics of a monofilar spiral antenna excited through a helical wire are investigated using the method of moments. The spiral has a circumference of more than two wavelengths (2.3λ₆, where λ₆ is the wavelength at a test frequency of 6 GHz) to obtain a tilted beam. An input impedance of approximately 50 Ω is realized by appropriately selecting the diameter and pitch angle of the helical wire. The antenna shows a gain of approximately 8 dB relative to an isotropic source in the maximum beam direction (18° from the direction normal to the antenna plane) and a VSWR frequency bandwidth of approximately 12%.

Keywords

antenna feeds; antenna radiation patterns; electric impedance; method of moments; spiral antennas; wire antennas; VSWR frequency bandwidth; antenna plane; antenna radiation characteristics; circumference; coaxial line feed; diameter; helical wire excited antenna; input impedance; isotropic source; method of moments; monofilar spiral antenna; pitch angle; straight wire spiral antenna; test frequency; tilted beam; Coaxial components; Directive antennas; Feeds; Frequency; Helical antennas; Impedance; Moment methods; Spirals; Testing; Wire;

fLanguage

English

Journal_Title

Antennas and Propagation, IEEE Transactions on

Publisher

ieee

ISSN

0018-926X

Type

jour

DOI

10.1109/TAP.2003.809865

Filename

1201343