Research On MIMO Antenna Based On Magneto-electric Dipole

Multiple input multiple output(MIMO)technology can improve the capacity of communication system without increasing the bandwidth and transmitting power,and it has become the key technology of the fifth-generation mobile communication(5G).Compared with the single-polarization antenna,the dual-polarization antenna has good polarization diversity ability in wireless communication system,which can improve the channel capacity and spectral efficiency,thus further improving the communication quality.The magneto-electric dipole antenna designed according to the principle of complementary antenna,it has the advantages of wide frequency band,almost symmetrical plane E and plane H of radiation pattern and low cross-polarization,which is expected to be more widely used in wireless communication system.It is of great theoretical and practical value to study how to realize a compact dual-polarization MIMO antenna based on magneto-electric dipole.In order to meet the demand of wireless communication system for compact antenna,this thesis firstly studies the miniaturization of magneto-electric dipole antenna,designs a single-polarized substrate integrated magneto-electric dipole antenna with slot coupling feed,and further proposes a dual-polarized substrate integrated magneto-electric dipole antenna with low profile and high isolation.Furthermore,by reducing the distance between the MIMO antenna units,more magneto-electric dipole antennas can be placed in a limited space,and a dual-polarized substrate integrated magneto-electric dipole MIMO antenna is designed.The main contents are as follows:1.Miniaturized substrate integrated magneto-electric dipole antenna design for single-polarized antenna.A miniaturized wideband substrate integrated magneto-electric dipole antenna is proposed.The microstrip gap coupling feeding method is adopted to broaden the bandwidth of the antenna.The relative bandwidth of the antenna reaches 52%(2.9-4.92GHz),and the maximum gain reaches 7 dBi.Moreover,the gain fluctuation is very small within the covered frequency range.2.Design of dual-polarized substrate integrated magneto-electric dipole antenna with low profile and high isolation.Based on the single-polarized substrate integrated magneto-electric dipole antenna,a kind of dual-polarized substrate integrated magneto-electric dipole antenna with low profile and high isolation was designed.The relative bandwidth of the antenna is up to 35%(3.1-4.4 GHz),the maximum gain is up to 6.7 dBi,and the gain fluctuation is small in the operating frequency band.At the same time,the isolation of different polarization ports of the antenna is greater than 33 dB.By comparing the simulation results of whether there is a ground parasitic radiation patch around the antenna,it is proved that adding a ground parasitic patch around the antenna can improve the matching and radiation characteristics of the antenna.3.Design of a wideband low-profile ±45° dual-polarized substrate integrated magneto-electric dipole MIMO antenna.First,a wideband low profile ±45° dual-polarized substrate integrated magneto-electric dipole antenna was designed.Then,the antenna unit is composed into 1×2 and 1×4 MIMO antennas.Both of these two kinds of MIMO antennas can obtain better port isolation characteristics under the condition that the unit spacing is half wavelength.Finally,the 1×4 MIMO antenna was machined and tested,and the test results verified the rationality of the design.