Single probe-fed circularly polarized patch antennas with U-slots

Detailed studies were presented for two recent designs of single probe-fed circularly polarized patch antennas with U-slots. In one design, a square patch with truncated corners is used to generate circular polarization, while a symmetric U-slot is etched on the patch to increase the usable bandwidth of the antenna. In the second design, both these functions are accomplished by means of an asymmetric U-slot in a square patch. Previously published studies were on air substrate only. One of the purposes of this article is to extend the study of the two designs for material substrates. The second purpose is to compare the performances of the two designs. It was found that, for the same substrate thickness, both the bandwidth and the gain of the symmetric design are somewhat better than the asymmetric design. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1245-1253, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26012 Copyright © 2011 Wiley Periodicals, Inc.