A Wideband Irregular Circular Polarization Antenna Analyzed by Characteristic Mode Theory

In this paper, a novel wideband circular polarization irregular slot antenna has been proposed. Based on the structure of irregular slot and amended strip line, the circular polarization can be realized. The dimensions of the proposed antenna are 40mm $\ast 40$ mm $\ast 1.6$ mm, only one substrate layer is employed in antenna design. To illustrate the working mechanism of the proposed antenna, the characteristic mode theory is conducted to analyze the proposed antenna, which demonstrate the proposed slot antenna has the potential to generate circular polarization wave around 2.95GHz. The simulated impedance matching bandwidth is 2.28–3.61GHz (45.8%) while the 3dB axial ratio bandwidth is 2.7–3.1GHz (15%), indicating that the result analyzed by characteristic mode theory is reasonable.