A Novel Broadband Circularly Polarized Monopole Antenna Based on C-Shaped Radiator

The design and implementation of a compact monopole antenna with broadband circular polarization is presented in this letter. The proposed antenna consists of a simple C-shaped patch and a modified ground plane with the overall size of 0.33 λ × 0.37 λ. By properly embedding a slit in the C-shaped patch and improving the ground plane with two triangular stubs, the measured broadband 3-dB axial-ratio bandwidth of 104.7% (2.05–6.55 GHz) is obtained, while the measured impedance bandwidth of 106.3% (2.25–7.35 GHz), defined by –10-dB return loss, is achieved. The performance for different parameters is analyzed. The proposed antenna is a good candidate for the application of various wireless communication systems.