A circularly polarized microstrip-fed T-slot antenna

This paper reports a study of a microstrip-fed T-type slot antenna for circular polarization. Two narrow slots are connected together in the T-type form and this T-slot antenna can be fed by a single microstrip line on the other side of the substrate for circular polarization. Ansoft´s Ensemble was used to model the return loss and axial ratio of this T-slot antenna. It is demonstrated that this simple T-type slot antenna with a single microstrip feed line can provide 12 percent bandwidth for 10 dB return loss and 5.5 percent bandwidth for 6 dB axial ratio. Measured results for the return loss agree well with the simulated ones by Ensemble.