Study on improved circularly polarized microstrip antennas with rotationally symmetric slots

In this paper, two different types of circularly polarized antennas operating in 2.5 GHz-3.0 GHz and 5.0 GHz-6.0GHz are proposed. In the first antenna 4-L parasitic elements & 4-L slots are added to the basic truncated edges circularly polarized antenna, similarly in the second antenna two rotationally symmetric S slots are introduced. Two different types of feeding techniques are used for feeding the antennas, a single feeding 50 Ω coaxial SMA connector and a single feeding 50 Ω coaxial SMA connector followed by the round microstrip line. The simulation result shows that the proposed two antennas obtain a wider impedance bandwidth and high gain above 8dB.