A dual-wideband 5G antenna with dual polarization in the sub-6 GHz band and 2 x 2 MIMO function in the 28-GHz band

A novel aperture-shared dual-wideband 5G antenna with dual polarization in the sub-6 GHz band and multi-input multi-output (MIMO) function in the 28-GHz band is presented in this work. A dual-polarized megnetoelectric dipole (ME-dipole) with wide bandwidth is introduced in the sub-6 GHz band. Based on the partial structure reuse method, four 2 x 2 substrate integrated waveguide (SIW) cavity-backed patch arrays are integrated into the electric dipole structure of the ME-dipole to construct a 28-GHz 2 x 2 MIMO system. Two high-order SIW cavity modes that cooperate with patch modes are used to enhance bandwidth in the 28-GHz band. For demonstration, a prototype of the proposed antenna was fabricated and measured. The simulated results are in good agreement with the measured results, showing wide bandwidths of 39.6% and 10.85% in the sub-6 GHz and the 28-GHz bands, respectively. In addition, excellent measured in-band and cross-band isolations of over 44.4 dB and 45.2 dB are obtained, respectively.