Millimeter-Wave Wideband Dual-Polarized Aperture-Coupled Magnetoelectric Dipole Antenna Array With High Isolation

This article presents a millimeter-wave (mm-wave) dual-polarized aperture-coupled magnetoelectric (ME) dipole antenna. To obtain superior antenna performance, three effective measures have been taken. First, the shorted patches that function as ME dipoles are connected through a crossed strip and fed by a pair of orthogonal H-shaped coupling slots, generating four resonant modes in the passband and hence effectively widening the impedance bandwidth. Second, a grounded coplanar waveguide (GCPW)-based crossover is utilized, ensuring consistent performance of two orthogonal polarizations while providing high isolation and symmetric radiation pattern. Third, four parasitic L-shaped patches and an X-shaped reflector are introduced, stabilizing the gain across the operating band. As a result, a broad −10-dB impedance bandwidth of 50.6% ( $23.3-39.1$ GHz), a high isolation level of over 32 dB, and a flat gain of $7.35-9.45$ dBi (H-polarization)/ $7.45-9.65$ dBi (V-polarization) are simultaneously achieved. Furthermore, using this antenna element, a $2\times2$ dual-polarized array is developed. In order to compensate the gain loss caused by large ground plane, metallic cavity and defected ground surface (DGS) are adopted. The measured results show that this array has a high isolation of over 29 dB and a peak gain up to 15.9 dBi in a wide bandwidth of 53.3% ( $22-38$ GHz). With merits of wide bandwidth, high isolation, and stable gain, the proposed dual-polarized ME dipole antenna and array are promising for mm-wave communication systems.