Wideband Circularly Polarized Antenna for L-band Satellite Communication

This paper presents a compact circularly polarized (CP) cross-dipole antenna operating in the L-band. It comprises a metallic cross dipole for radiation, a feeding structure connected with a coupled 3dB bridge for providing a 90° phase difference feed, and a cavity-backed reflector to enhance the gain and front-to-back ratio. The four arms of the cross dipole are meticulously designed in four distinct directions, enabling the realization of circular polarization performance. The simulation results of the proposed antenna, which has an overall size of $0.067 \lambda_{0} \times 0.067 \lambda_{0} \times 0.133 \lambda_{0}\left(\lambda_{0}\right.$ is the free space wavelength at the lowest operating frequency), show an impedance bandwidth (IBW) of $\mathbf{8 7. 8 \%}$ for VSWR $\lt2$ and a $3-\mathrm{dB}$ axial ratio bandwidth (ARBW) of 77.2%. The proposed antenna exhibits stable left-hand circular polarization (LHCP) radiation patterns and a peak realized gain of 6.5 dBic.