Novel dual circular polarization planar microstrip slot antenna

With the rapid development of wireless communication technology, how to use an antenna to realize the function of multiple antennas has become a hot research topic. The double circularly polarized antenna studied in this paper can achieve right-handed circular polarization and left-handed circular polarization in the same frequency band by using a circular annular groove and two orthogonal L-shaped feed lines in the ground plane. At the same time, properly grooving at the center of the ground plane and adding parasitic elements to the front of the L-shaped feed line can change the current on the surface of the feed line and in the ground plane, thereby improving the circular polarization performance of the antenna. Measurement and simulation results show that the impedance bandwidth of the antenna is about 59% (3.13~5.75GHz), and the 3dB axial ratio bandwidth is about 40.5% (3.23~4.87GHz). Also, the isolation between the two ports is higher than 10dB. The results show that the designed antenna has a good performance in both impedance bandwidth and axial ratio bandwidth.