Downsized Bow-Tie Antenna with Folded Elements

Mio NAGATOSHI  Shingo TANAKA  Satoru HORIUCHI  Hisashi MORISHITA 

Publication
IEICE TRANSACTIONS on Electronics  Vol.E93-C  No.7  pp.1098-1104
Publication Date: 2010/07/01
Online ISSN: 1745-1353
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Section on Recent Progress in Microwave and Millimeter-Wave Technologies)
Category: 
Keyword: 
wideband antenna,  bow-tie antenna,  folded element, 

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Summary: 
It has been reported that by adding two folded elements, bow-tie antenna can be miniaturized, but the antenna has VSWR degradation problem. In this paper, the details of the VSWR degradation are investigated and the physical mechanism of the degradation is clarified. The best position for folded element is also shown. Moreover, the bow-tie antenna is bent in half in order to realize more size reduction. When the two folded elements are added to the half bent bow-tie antenna, the lowest operation frequency goes down and the proposed antenna can be more downsized than the previous proposed antenna. The gain is slightly lower than that of the previous model, however, the antenna area is reduced from 31%, which is the antenna area ratio of privious proposed antenna and conventional bow-tie antenna, to 19%. The bandwidth of 92% is obtained for VSWR≤2.