Document Type

Article

Rights

This item is available under a Creative Commons License for non-commercial use only

Publication Details

In IET Microwaves, Antennas & Propagation, February, 2008, Vol.2, pp.42-47. ISSN: 1751-8725 Digital Object Identifier: 10.1049/iet-map:20070053 Available from http://0-ieeexplore.ieee.org.ditlib.dit.ie/stamp/stamp.jsp?tp=&arnumber=4447453&isnumber=4447444

Abstract

Methods to mitigate the strong dependence of impedance bandwidth on the ground- plane size for a rectangular printed planar monopole is described. It is shown that the bandwidth limitation may be overcome by introducing feed-line asymmetry, which alters the purity and the Q of the higher frequency modes and by ground-plane augmentation, which effects the lower frequency modes. A method of extending the ground plane without increasing the overall antenna size is shown to improve both the bandwidth and gain and also to enable the use of significantly smaller ground planes. The effects of these techniques on radiation pattern are discussed.