A Compact and Wideband Circularly Polarized Hybrid Ring CDRA for C/X/Ku-Band Communication

A wideband and circularly polarized hybrid ring CDRA is proposed for the applications of C, X and Ku-band. A small size two-headed drum-shaped aperture (Damaru shaped) inclined at 45° and microstrip line feed generates two orthogonal modes (HEM^x_11δ and HEM^y_11δ). The suggested ring CDRA of wideband characteristic is resonating between frequency band 6.96 to 14.12 GHz with 67.93% (7160 MHz) impedance bandwidth. oreover, dual-band circular polarization characteristics are also achieved from 8.22 to 9.53 GHz and 12.29 to 13.71 GHz with 3-dB axial ratio bandwidth (ARBW) of 14.76% (1310 MHz) and 10.92% (1420 MHz) respectively. The impact of various parameters of ring CDRA and aperture orientation on the functionality of the suggested antenna is also studied. The proposed radiator is fabricated on a 40 × 40 mm² (0.93 × 0.93λ₀² at lower cut-off frequency 6.96 GHz) FR-4 substrate of 1.6 mm thickness. Moreover, peak gain of 7.43 dB at frequency 12.66 GHz and radiation efficiency greater than 80% in the whole operating frequency is also achieved.