Cavity-Backed Circularly Polarized Cross-Dipole Phased Arrays

In this letter, a 16 × 16 Ku-band circularly polarized phased array is proposed. The antenna element comprises a cross dipole, a metal cavity, and a threaded SMP connector. The metal cavity makes the gain of the antenna increased and the mutual coupling between the array elements is reduced, thus ensuring good impedance matching and axis ratio (AR) during the two-dimensional beam scanning. The mutual coupling of the center element at center frequency is −26.6 dB when the cavity is added. The proposed phased array achieves the impedance bandwidth ( $| {{{\boldsymbol{S}}_{11}}} | \le - 10{\rm{\ dB}}$ ) of 10.1% (13.1–14.5 GHz) when scanning ±40° in the xz plane and yz plane. AR of the main lobe is less than 2 dB in the total scanning range. The gain fluctuation is less than 3 dB during scanning. This letter presents the measurement and simulation results, verifying that the phased array has good performance.