A Broadband Dual-Polarized ME-Dipole Antenna Array for Millimeter-Wave Applications

A magneto-electric dipole implemented using substrate integrated blocks (SIBs) is proposed for broadband dual-polarized array application. Facilitated by the SIB-based design approach, an interlaced arrangement of the perpendicular feeding probes is developed for dual-polarization excitation. While maintaining the wideband feature and single-layered antenna structure, nearly identical radiation characteristics for the two polarizations have been achieved. Additionally, the enlarged probe-to-probe distance increases the degree of design freedom for the feeding network. As a proof-of-concept, a 3 × 3 single-layered antenna array fed by a single-layered dual-polarization microstrip-line feeding network is designed and fabricated at the 5G millimeter-wave frequency band. The measured results indicate that the array prototype has a wide overlapped impedance bandwidth of 36.2%, covering from 21.3 to 30.7 GHz, within which a maximum gain of 14.7 dBi and a gain variation of 2 dB are maintained. The broadband performance, single-layered radiating structure, and nearly identical performance of two polarizations make the proposed design attractive for applications including 5G and beyond.