Circularly polarized cross-slot antenna array fed by substrate integrated waveguide

A circularly polarized antenna array is proposed by loading a cavity-backed cross-slot antenna over the longitudinal slots on the SIW upper layer in this paper. The longitudinal slots are etched to couple energy to array from SIW. The cavity-backed cross-slot antenna is designed to achieve CP radiation. The radiation unit has good isolation characteristic, which is desirable to design a circularly polarized antenna array. A 1-by-8 circularly polarized array operating at 10 GHz has been developed. Simulated impedance bandwidth of 4.6%, the 3-dB axial ratio bandwidth of 2.1%, the gain of 13.82dB and cross polarization levels of about 24.22dB have been achieved. Moreover, the proposed antenna owns the easy processing and the low profile. It can be conveniently expanded to a larger wideband CP array with a higher gain, which is preferred for the specific satellite communication applications.