Low-Profile Dual-Wideband Dual-Polarized Antenna for 5G Millimeter-Wave Communications

This letter presents a dual-wideband dual-polarized antenna that fully covers the fifth-generation (5G) millimeter-wave (mm-wave) bands of n257−n261 (24.25–29.5 GHz and 37–43.5 GHz), and that shows a low-profile feature and a band-stop filtering response. For each polarization, the low-band and high-band radiation modes are, respectively, achieved by the two pairs of U-shaped dipole arms which are distributed along the co- and cross-polarized directions. Meanwhile, a radiation null is generated by the radiating cancellation effect of the two pairs of dipole arms, suppressing the unwanted frequency between the two operating bands. Moreover, an extra high-band resonant mode is introduced by the parasitic patches, enhancing the bandwidth of the proposed antenna. Furthermore, a vertical balun structure connecting each dipole arm with the ground is bent to reduce the antenna profile. In the fabrication, high-density interconnect printed circuit board process is employed to meet the antenna-in-package consideration. Under the constrained substrate thickness of 1 mm, the proposed antenna achieves a dual-wideband operation of 24–30 GHz (22%) and 37–43.5 GHz (16%). These merits make the proposed antenna suitable for 5G mm-wave communications.