Electrically steerable passive array radiator (ESPAR) antennas

Author

Kawakami, Haruo ; Ohira, Takashi

Author_Institution

Antenna Giken Co., Ltd., Japan

Volume

47

Issue

2

fYear

2005

fDate

4/1/2005 12:00:00 AM

Firstpage

43

Lastpage

50

Abstract

A novel ground-plane shape to improve the horizontal gain for electrically steerable passive array radiator (ESPAR) antennas is investigated. The peak directivity of a monopole antenna with a finite ground plane, such as a circular or rectangular ground plane is at a higher angle from the horizon. Thus, the horizontal gain is lower than that of a dipole antenna. Using a circular ground plane of a half-wavelength radius with a skirt of a quarter wavelength wound around it, the angle of the peak directivity and the horizontal gain for the ground-based communication system were improved. For an ESPAR antenna - one of the monopole arrays - the horizontal gain was also improved. It was confirmed that it was possible to form the main-beam radiation and a beam in the horizontal plane, each in an arbitrary direction, by changing the control voltage to the passive element. This was shown by an experiment with an ESPAR antenna with a finite reflector, a feed element, and seven passive elements.

Keywords

antenna feeds; antenna radiation patterns; beam steering; dipole antenna arrays; monopole antenna arrays; beam; circular ground plane; dipole antenna; electrically steerable passive array radiator antennas; feed element; finite ground plane; finite reflector; ground-based communication system; ground-plane shape; half-wavelength radius; horizontal gain; main-beam radiation; monopole antenna peak directivity; monopole arrays; quarter wavelength; seven passive elements; Adaptive arrays; Antenna arrays; Diodes; Dipole antennas; Directive antennas; Feeds; Shape; Varactors; Voltage control; Wounds;

fLanguage

English

Journal_Title

Antennas and Propagation Magazine, IEEE

Publisher

ieee

ISSN

1045-9243

Type

jour

DOI

10.1109/MAP.2005.1487777

Filename

1487777