A Novel Electromagnetic Transparent Antenna for 4G/5G Dual-Band Share-Aperture Array

A novel electromagnetic (EM) transparent antenna is proposed for 4G/5G dual-band share-aperture base station antenna array. The proposed antenna is a dual-polarized square ring dipole antenna loaded by some helical coupling structures (HCSs) and operates in the low band (LB) 820–960 MHz (4G band). The proposed EM transparent antenna can suppress the high-band (HB) 3.4–3.8 GHz (5G band) induced current to reduce the mutual coupling, so LB antenna elements can be embedded in the HB massive multple-input--multiple-output (MIMO) antenna array to form a dual-band share-aperture base station antenna array. The prototype of the dual-band antenna array is fabricated and measured. The measured results show that the LB antenna achieves high port isolation (>29 dB), good impedance matching (VSWR <1.5), and weak cross-band coupling between the LB and HB elements. Therefore, the proposed antenna array can work in 4G and 5G bands, respectively. This dual-band antenna array has a small size, lightweight, and high space utilization, which can be widely used in future wireless communication systems.