A Multi-Polarization Series-Fed Antenna Array Based on Eccentric Ring

A multi-polarization series-fed antenna working at 10 GHz is presented in this paper. The patch elements are built by eccentric rings which can realize the performance of circular polarization. The dual-port feeding allows us to switch the polarization of the antenna. The right-hand circular polarization (RHCP), left-hand circular polarization (LHCP), and Linear polarization (LP) polarization can be realized by properly feeding form. The changing of antenna polarization without switch controlling. Owing to the circular array arrangement, the antenna can form a compact structure. The key features of this array are multi-polarization and traveling-wave series-fed performance. The axial ratios are lower than 3dB measured. The $\vert \text{S}_{21}\vert $ is lower than −14 dB in the mentioned bandwidth. Then, a $4\times $ 4 MIMO array which has compact structure is designed and simulated. The circular array is processed and measured. The experimental and simulation results are in good agreement.