Dual circularly polarized falcate-shaped slot antenna

In this paper, the design of a low-profile slot antenna with dual microstrip feeds is presented for broadband dual circular polarization. The proposed antenna is composed of a falcate-shaped slot to achieve broadband circularly polarized radiation and two individual 50-Ω microstrip feeds to realize both right- and left-hand circular polarizations simultaneously at the same frequency. The overall dimensions of the fabricated antenna are 50 * 50 * 0.76 mm³. The measured −10 dB reflection bandwidths at port 1 and port 2 are 31.14% (5.64–7.72 GHz) and 30.05% (5.6–7.58 GHz), respectively. Furthermore, a port coupling level of less than −15.68 dB was also achieved across the operation band. The fabricated antenna also exhibits 3 dB axial ratio bandwidths of 56.47% (4.6–8.22 GHz) and 54.06% (4.63–8.06 GHz) for right- and left-hand circular polarizations, respectively. The measured peak gains are higher than 3.66 dBic for both polarizations.