Bidirectional Rod Antennas Comprising Collinear Antenna and Parasitic Elements

Keizo CHO  Toshikazu HORI  Hajime TOZAWA  Shinji KIYA  

IEICE TRANSACTIONS on Communications   Vol.E81-B   No.6   pp.1255-1260
Publication Date: 1998/06/25
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: PAPER
Category: Antennas and Propagation
base station antenna,  bidirectional antenna,  rod antenna,  microcell system,  

Full Text: PDF(616.7KB)>>
Buy this Article

This paper proposes a novel bidirectional rod antenna (BIRA) comprising a collinear antenna and parasitic wires as a base station antenna for a street microcell. The spacing between the collinear antenna and the parasitic wire, and the length of the parasitic wires, which are the design parameters obtaining a bidirectional pattern, are investigated using the moment method. The results show that wide spacing enlarges the bandwidth obtaining the bidirectional pattern, however it decreases the gain. Furthermore, to enlarge the bandwidth, a BIRA with arc parasitic plates whose radius is the same as that of the radome is also proposed. The configuration can be constructed using the same exterior as the BIRA with parasitic wires. It is also shown that the arc parasitic plates enlarge the bandwidth in proportion to the area projected onto the tangential plane at the center of the arc. Finally, a prototype of the proposed antenna is shown.