Numerical simulations on beam and/or null forming performance of ESPAR antennas

Akira Akiyama, Koichi Gyoda, Takashi Ohira, Makoto Ando

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

The radiation pattern of the ESPAR antenna is controlled by variable reactances loaded to its passive elements. In this paper, the effects of the number of elements and the variable range of the reactance value on the beam and null forming capability are studied by simulation using the method of moments. It is found that a beam with a directivity of more than 8 dBi and a null of less than -40 dBi can be scanned independently in all directions when the number of elements is more than 5 and the reactance value range is ±50 Ω. The reactance range of ±50 Ω is needed for simultaneous forming of a single beam of more than 5 dBi and a single null of less than -30 dBi, while ±100 Ω is needed for simultaneous forming of a single beam of more than 5 dBi and multiple nulls of less than -15 dBi. The direction of the beam and null can be close as the number of elements is increased. The input impedance of the feed element is also studied and the standard return loss of a seven-element antenna is found to be 15.8 dBi.

Original languageEnglish
Pages (from-to)1-11
Number of pages11
JournalElectronics and Communications in Japan, Part I: Communications (English translation of Denshi Tsushin Gakkai Ronbunshi)
Volume86
Issue number12
DOIs
Publication statusPublished - 2003
Externally publishedYes

Fingerprint

Antennas
Computer simulation
Directional patterns (antenna)
Method of moments

Keywords

  • Adaptive antenna
  • Beam forming
  • ESPAR antenna
  • Null forming
  • Return loss
  • Variable reactor

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Computer Networks and Communications

Cite this

@article{62f9d7e39b884690aa1955baa44f9e64,
title = "Numerical simulations on beam and/or null forming performance of ESPAR antennas",
abstract = "The radiation pattern of the ESPAR antenna is controlled by variable reactances loaded to its passive elements. In this paper, the effects of the number of elements and the variable range of the reactance value on the beam and null forming capability are studied by simulation using the method of moments. It is found that a beam with a directivity of more than 8 dBi and a null of less than -40 dBi can be scanned independently in all directions when the number of elements is more than 5 and the reactance value range is ±50 Ω. The reactance range of ±50 Ω is needed for simultaneous forming of a single beam of more than 5 dBi and a single null of less than -30 dBi, while ±100 Ω is needed for simultaneous forming of a single beam of more than 5 dBi and multiple nulls of less than -15 dBi. The direction of the beam and null can be close as the number of elements is increased. The input impedance of the feed element is also studied and the standard return loss of a seven-element antenna is found to be 15.8 dBi.",
keywords = "Adaptive antenna, Beam forming, ESPAR antenna, Null forming, Return loss, Variable reactor",
author = "Akira Akiyama and Koichi Gyoda and Takashi Ohira and Makoto Ando",
year = "2003",
doi = "10.1002/ecja.10141",
language = "English",
volume = "86",
pages = "1--11",
journal = "Electronics and Communications in Japan, Part I: Communications (English translation of Denshi Tsushin Gakkai Ronbunshi)",
issn = "8756-6621",
publisher = "John Wiley and Sons Inc.",
number = "12",

}

TY - JOUR

T1 - Numerical simulations on beam and/or null forming performance of ESPAR antennas

AU - Akiyama, Akira

AU - Gyoda, Koichi

AU - Ohira, Takashi

AU - Ando, Makoto

PY - 2003

Y1 - 2003

N2 - The radiation pattern of the ESPAR antenna is controlled by variable reactances loaded to its passive elements. In this paper, the effects of the number of elements and the variable range of the reactance value on the beam and null forming capability are studied by simulation using the method of moments. It is found that a beam with a directivity of more than 8 dBi and a null of less than -40 dBi can be scanned independently in all directions when the number of elements is more than 5 and the reactance value range is ±50 Ω. The reactance range of ±50 Ω is needed for simultaneous forming of a single beam of more than 5 dBi and a single null of less than -30 dBi, while ±100 Ω is needed for simultaneous forming of a single beam of more than 5 dBi and multiple nulls of less than -15 dBi. The direction of the beam and null can be close as the number of elements is increased. The input impedance of the feed element is also studied and the standard return loss of a seven-element antenna is found to be 15.8 dBi.

AB - The radiation pattern of the ESPAR antenna is controlled by variable reactances loaded to its passive elements. In this paper, the effects of the number of elements and the variable range of the reactance value on the beam and null forming capability are studied by simulation using the method of moments. It is found that a beam with a directivity of more than 8 dBi and a null of less than -40 dBi can be scanned independently in all directions when the number of elements is more than 5 and the reactance value range is ±50 Ω. The reactance range of ±50 Ω is needed for simultaneous forming of a single beam of more than 5 dBi and a single null of less than -30 dBi, while ±100 Ω is needed for simultaneous forming of a single beam of more than 5 dBi and multiple nulls of less than -15 dBi. The direction of the beam and null can be close as the number of elements is increased. The input impedance of the feed element is also studied and the standard return loss of a seven-element antenna is found to be 15.8 dBi.

KW - Adaptive antenna

KW - Beam forming

KW - ESPAR antenna

KW - Null forming

KW - Return loss

KW - Variable reactor

UR - http://www.scopus.com/inward/record.url?scp=0038678668&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0038678668&partnerID=8YFLogxK

U2 - 10.1002/ecja.10141

DO - 10.1002/ecja.10141

M3 - Article

VL - 86

SP - 1

EP - 11

JO - Electronics and Communications in Japan, Part I: Communications (English translation of Denshi Tsushin Gakkai Ronbunshi)

JF - Electronics and Communications in Japan, Part I: Communications (English translation of Denshi Tsushin Gakkai Ronbunshi)

SN - 8756-6621

IS - 12

ER -