Resonant frequency of a shorted circular patch with the use of a modified impedance expression for a metallic post

The accuracy of the cavity-model analysis of a shorting post loaded circular microstrip antenna depends strongly on the exact modeling of the metallic post in the radial guide. This Letter presents an empirically generated expression for the impedance of such a post. The expression takes the edge effects into account, and its use results in a very accurate prediction of resonant frequency for all the eigenmodes of a shorting post loaded circular patch. The theoretical model is extensively compared with measured/simulated results and shows excellent agreement. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 252–256, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10290