Switched-Beam Slot Antenna over Electromagnetic Band-Gap Reflector

Hiroyuki UNO  Yutaka SAITO  Yoshio KOYANAGI  Satoshi YAGITANI  Isamu NAGANO  

IEICE TRANSACTIONS on Communications   Vol.E90-B   No.9   pp.2263-2270
Publication Date: 2007/09/01
Online ISSN: 1745-1345
DOI: 10.1093/ietcom/e90-b.9.2263
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Section on 2006 International Symposium on Antennas and Propagation)
Category: Antennas
switched-beam antenna,  tilted beam,  electromagnetic band-gap(EBG) reflector,  slot antenna,  

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This paper presents the switched-beam slot antenna over the electromagnetic band-gap (EBG) reflector. This antenna is composed of two slot elements fed with a phase difference and the EBG reflector, which is used in order to realize a low profile structure. The radiation characteristics of this antenna are calculated using the FDTD method. Calculations show that the height of the antenna using the EBG reflector is 60 % lower than that of the antenna using a perfect electric conductor (PEC) reflector. The radiation characteristics at the center of the operating frequency band in the EBG reflector are equivalent to that in the PEC reflector. It is shown that the tilt angle of the main beam in the elevation plane varies with the operating frequency, and the variation in the case of the EBG reflector is caused by its frequency-dependent reflection phase. Moreover, the radiation pattern of the fabricated antenna is measured. The results demonstrate that the low profile design can be achieved by using the EBG reflector, and reveal the influence of the EBG reflector on the antenna efficiency.