DocumentCode :
1000681
Title :
On linear parasitic array of dipoles with reactive loading
Author :
Seth, Devendra P S ; Chow, Y. Leonard
Author_Institution :
University of Waterloo, Waterloo, Ont. Canada
Volume :
21
Issue :
3
fYear :
1973
fDate :
5/1/1973 12:00:00 AM
Firstpage :
286
Lastpage :
292
Abstract :
Center loaded linear parasitic arrays of dipoles are examined. It is shown that capacitive loading increases the phase velocity of the slow wave on the structure while inductive loading reduces it. For the infinite array, used as a transmission line, this has the effect of modifying the cutoff frequency and the bandwidth. This is experimentally verified for the capacitive loading. For a simple finite array without a reflector, due to end effects only a small bandwidth widening is observed. However, when the finite array is attached with a suitable reflector, a significant widening of bandwidth is observed. In both these cases the loading causes a significant shifting of the center operating frequency. This effect is utilized to build a tunable Yagi array with varactor loading. With variable bias this loading can effectively be adjusted to double the operational bandwidth. Also it is shown that it is possible to sustain the optimum array directivity over a very wide bandwidth without bias adjustments, by a special loading network.
Keywords :
Dipole arrays; Loaded antennas; Parasitic antennas; Yagi - Uda arrays; Antenna arrays; Bandwidth; Cutoff frequency; Dipole antennas; Linear antenna arrays; Loaded antennas; Phased arrays; Transmission lines; Varactors; Yagi-Uda antennas;
fLanguage :
English
Journal_Title :
Antennas and Propagation, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-926X
Type :
jour
DOI :
10.1109/TAP.1973.1140489
Filename :
1140489
Link To Document :
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