DocumentCode
838125
Title
Capacitive matching of microstrip patch antennas
Author
Alexander, M.J.
Author_Institution
GEC-Marconi Res. Centre, Chelmsford, UK
Volume
136
Issue
2
fYear
1989
fDate
4/1/1989 12:00:00 AM
Firstpage
172
Lastpage
174
Abstract
The input impedance of a thick microstrip patch antenna is inherently inductive. The patch can be matched by using a capacitive annular gap round the feed point. By varying the amount of capacitance the input resistance is also varied. It is shown that input resistances in the range 40 to 120 ohms can be chosen by varying the radius of the annulus. A return loss of -20 dB over a bandwidth of 13% was achieved. An equivalent circuit model is described which can be used as a design aid.
Keywords
antenna theory; impedance matching; microstrip antennas; transmission line theory; capacitive annular gap; equivalent circuit model; feed point; input resistance; microstrip patch antennas;
fLanguage
English
Journal_Title
Microwaves, Antennas and Propagation, IEE Proceedings H
Publisher
iet
ISSN
0950-107X
Type
jour
Filename
18989
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