| The fifth generation mobile communication application spectrum will be highfrequency.The application of the millimeter wave band with rich frequency resources can improve the tense situation of the existing band below 6 GHz.But the high transmission loss of millimeter-wave system is a challenge to the development of millimeter-wave communication system.How to abate the transmission loss of millimeter-wave antenna to improve the efficiency of operations and ensure the spectrum coefficient of utilization is a tremendous problem.Based on the background of millimeter-wave technology and dual-frequency antenna,two kinds of millimeter-wave dual-frequency antennas are designed for the future mobile communication technology.Firstly,a dual band MIMO antenna based on metamaterials is designed by placing three different metamaterial structures in the middle of two parallel dielectric resonator antennas.The simulation results show that the antenna loaded with metamaterial structure works in millimeter wave band and exhibits dual-frequency characteristics.Compared with the antenna without metamaterial structure,the working bandwidth of the antenna with vertical metamaterial element(VME)and vertical metamaterial polarization rotation(VMPR)wall is increased by 2.61 GHz and 1.01 GHz.The coupling between MIMO antenna cells is restrained when the antenna loaded with transverse metamaterial polarization rotation(TMPR)wall,and the port isolation in the operating band increased by an average of 10 d B.Next,a multi frequency stacked microstrip antenna is designed.The microstrip patch antenna working in microwave band and array antenna working in millimeter wave band are vertically combined to make the antenna have multi frequency characteristics.The calculation methods of microstrip antenna size at two frequencies are also analyzed.In order to improve the function of the antenna,the dumbbell shaped DGS is etched on the antenna ground plate.The three working frequencies of the antenna are 5.83 ～ 5.97 GHz,28.03 ～29.28 GHz and 30.06 ～ 30.83 GHz,respectively.By loading DGS,the port isolation of the antenna in high frequency band is increased by 14 d B on average,and the antenna shows better omnidirectional performance in high frequency band.Figure 51;Table 3;Reference 70... |
