The Research Of Dual-Band MIMO Antennas For 5G Smartphones

In recent years,with the booming development of smartphones and wireless communication technology,MIMO mobile phone antennas have become a popular research topic on account of the advantages of low channel interference,high data transmission rate and low signal loss.Because MIMO mobile phone antennas are limited by spaces,antenna miniaturization and decoupling techniques are very important.This paper focuses on researching dual-band 5G MIMO mobile phone antennas and designing antennas to meet the current needs of smartphones.The paper concentrates on antenna miniaturization,broadband and decoupling,and the main research results are as follows.Firstly,this paper introduces the basic antenna theory,antenna miniaturization technology and MIMO antenna decoupling technology,etc.The paper provides a brief overview of the current research and application of MIMO mobile phone antennas and related technologies at home and abroad.Secondly,an 8×8 MIMO dual-band cell phone antenna based on a slot structure is designed to operate in the 3.5GHz band(3400MHz-3600MHz)and the 5GHz band(4800MHz-5100MHz).The coupling between the antenna units is reduced by arranging the antenna units on the side frame and floor separately to form orthogonal polarization.Antenna measured results show that its isolation is better than-17 d B.Finally,considering that the antenna design on the side frame is not conducive to curved screen phone design,the radiation performance is limited by the floor area and the operating band is narrow.An eight-port wideband dual-band MIMO mobile phone antenna etched on the floor is designed,covering the N78 band(3300MHz-3800MHz)and N79 band(4400MHz-5000MHz).The antenna units reduce size by importing comb branches as well as T-shaped protruding ground structure,and the gap structure size is only 12mm×2.9mm.The antenna unit reduces the coupling between compact antenna units by reasonable layout and etching Y-shaped defective ground structure on the floor.The final measured results of isolation are respectively better than-15.3d B and-12.2d B on the whole low and high frequency band.