Off-campus UMass Amherst users: To download dissertations, please use the following link to log into our proxy server with your UMass Amherst user name and password.

Non-UMass Amherst users, please click the view more button below to purchase a copy of this dissertation from Proquest.

(Some titles may also be available free of charge in our Open Access Dissertation Collection, so please check there first.)

Analysis of probe-fed circular microstrip antennas

James T Aberle, University of Massachusetts Amherst


The Green's function/moment method approach is used to solve a number of problems involving circular microstrip patch antennas. These problems include radiation and scattering from isolated circular patches, mutual coupling between circular patches and input impedance of circular patches in the infinite array environment. In all cases, the patches are probe-fed via the center conductor of a coaxial transmission line. Initially, the probe feed is modeled as a short electric line current which excites current on the patch. This idealized probe feed model approach ignores the probe self-impedance as well as the rapidly-varying patch current in the vicinity of the feed connection point. Later, a rigorous probe feed model which overcomes these deficiencies is developed and used in the analysis of both isolated circular patches and circular patches in infinite arrays. An additional topic investigated is the effect of suspending a dielectric layer above the substrate. Extensive measurements are done to confirm the numerical solutions developed. For the infinite array cases, verification is achieved using waveguide simulator experiments. In general, the measurements indicate that the idealized probe feed model is adequate for antennas and arrays printed on substrates that are electrically thin and for predicting general performance trends. However, the rigorous probe feed model is more accurate and is useful over a wider range of practical substrate dielectric constants and thicknesses.

Subject Area

Electrical engineering

Recommended Citation

Aberle, James T, "Analysis of probe-fed circular microstrip antennas" (1989). Doctoral Dissertations Available from Proquest. AAI9001476.