A Wideband Differentially Fed Dual-Polarized Laminated Resonator Antenna

A wideband differentially fed dual-polarized laminated resonator antenna (LRA) is presented in this communication. Two differential pairs of L-probes are inserted into the LRA to excite degenerate dominant modes in LRA for dual-polarized operation. As a proof of concept, a prototype antenna centered at 5 GHz is designed, fabricated, and measured. The measured results agree well with the simulated ones. The experimental results show that the designed antenna achieves a wide bandwidth of 29% with differential reflection coefficient less than -10 dB. Moreover, it exhibits stable and symmetrical radiation patterns within the bandwidth. Benefiting from the differentially fed scheme, high port-to-port isolation better than 35 dB and low cross-polarization level less than -25 dB are achieved across the entire operating band. The proposed antenna is the first differentially fed dual-polarized LRA. Taking advantage of its planar structure integrated in the substrate, the proposed antenna is a promising candidate for future 5G wireless communications and antenna-in-package (AiP) solutions in millimeter-wave frequencies.