Bandwidth enhancement techniques for low-profile antennas: Theory and experiment

This thesis describes techniques for bandwidth enhancement for low-profile antennas. The first method involves the use of coupled resonators. In particular, two cavity-backed slot antennas are coupled through an aperture in a common wall. One cavity-backed slot antenna, of the coupled antenna system, is driven. This coupled antenna system is analyzed using two different approaches. The first approach employs the cavity-model theory in conjunction with a variational procedure. Both experimental and theoretical results are presented and there is good agreement between the two. The second approach in the analysis of the coupled cavity-backed slot antenna used the boundary-integral method. This method, which was previously introduced for the analysis of planar microwave circuits, has been extended to the analysis of thin microwave antennas. The results from the boundary-integral method compare reasonably well with with the measured data. The boundary-integral method is also used to predict the performance of various microstrip antennas. These microstrip patch antennas, in general, can have arbitrary perimeters, load slots, and shorting pins. Both theoretical and experimental results are given. The coupled-resonator approach is shown to produce greater than two-fold increases in operating bandwidth. For even wider bandwidths a second method is demonstrated. This second method uses a log-periodic array of dual-feed microstrip patch antennas. Experimental results are provided for this array.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Electrical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2011

Author dc:creator

• Smith, Hugh Kennedy

Contributors dc:contributor

• Mayes, Paul E.

• Engineering, Electronics and Electrical

Statement dc:rights

• Copyright 1991 Smith, Hugh Kennedy

Language dc:language

eng

Identifier

AAI9124491
(UMI)AAI9124491

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/21322