A broadband and low cross-polarization balanced dual-polarized cross quasi-yagi antenna

A broadband balanced fed dual-polarized cross quasi-Yagi antenna with a compact size, low cross-polarization, and good common-mode (CM) suppressions is provided. The proposed antenna consists mainly of two balanced quasi-Yagi antennas, which are vertical to each other. Balanced microstrip-slotline feeding line structures are utilized to excite the two quasi-Yagi antennas to achieve +/- 45 degrees linear polarizations. A good end-fire radiation in a broad bandwidth is achieved by introducing the directors above the dipoles of the cross quasi-Yagi antenna. Meanwhile, a good wideband common-mode (CM) suppression and low cross-polarization levels are realized by the balanced microstrip-slotline feeding line structure. Besides, superior DM transmission and CM suppression are achieved intrinsically, thereby simplifying the design procedure significantly. Finally, the balanced dual-polarized antenna is fabricated to validate the feasibility of this design method. The measured dates show that the designed antenna characterizes broadband, high port isolation and CM suppression, low cross-polarization levels and stable gain radiation.