Characteristic Mode Analysis of Circularly-Polarized Guo-Shaped Patch Antenna

This paper presents an analysis of Guo-shaped patch antenna using characteristic mode theory. The circularly-polarized Guo-patch was initiated by the authors previously; however, narrow axial-ratio (AR) bandwidth and lack of design method were the disadvantages. The objective here is to explore the possibility of AR bandwidth enhancement. The analysis results indicate that the first two out of three dominant modes can be used for the generation of circular polarization at 2.5 GHz, whereas the third mode is created by the outer loop of the Guo-patch.