Mixed Metal Decoupling Structure for 5G MIMO Base Station Antenna Array

A decoupling concept using mixed metal decoupling structure (MMDS) is proposed for fifth-generation (5G) multiple-input multiple-output (MIMO) base station antenna array. In the operating bandwidth of 3.3-3.8 GHz, the co-polarized isolation is enhanced by at least 6 dB after loading MMDS. The dip of the radiation pattern is alleviated by the back cavities and metal walls. Moreover, the MMDS also effectively suppresses the cross-polarization. The proposed MIMO antenna array is simulated, fabricated and tested. The advantages of the MMDS include no additional profile height and simple structure.