Research And Design Of 28GHz Planar Broadband Millimeter Wave MIMO And Array Antenna

The continuous progress of science and technology has led to the continuous development of wireless communication technology.The available low-frequency spectrum resources have become increasingly scarce.At the same time,people's demand for high-speed communication has also continued to grow.Compared with low-frequency spectrum resources,the millimeter wave frequency band has a large number of continuous and uncommercialized spectrum resources,which can solve the current dilemma of lack of spectrum resources and can be applied to the next generation of high-speed wireless communication systems.The fourth-generation communication system introduces multiple input multiple output(MIMO)technology,which greatly improves the data transmission rate and accuracy.For lower frequency bands,the atmospheric attenuation of millimeter wave frequency band is more serious.Therefore,in the long-distance communication,the millimeter wave communication systems need to increase the antenna gain by means of arrays.This thesis takes the broadband design of the antenna as the starting point,and designs two MIMO antennas and array antennas with good performance respectively.The first MIMO antenna unit achieves broadband characteristics by performing secondary fractal iterations of regular hexagonal patches,while strip decoupling stubs greatly reduce the mutual coupling between antenna units.The first array antenna is based on the first MIMO antenna unit,and a one-to-four way in-phase power divider is designed to achieve high radiation gain of the antenna.The second MIMO antenna unit is based on an inverted L-shaped dipole structure,loaded with horizontal strip-shaped branches,and further expands the antenna bandwidth;loaded with butterfly parasitic elements,enhances the electric field distribution in the radiation direction,and further improves the antenna gain.The antenna units are placed in an orthogonal manner to improve the isolation of the MIMO antenna.The second array antenna is based on the second MIMO antenna unit,and a one-to-eight way in-phase power divider is designed to achieve high radiation gain of the antenna.This thesis uses HFSS 15.0 simulation software to model the antenna and optimize its structural parameters.Finally,the main performance parameters of the antenna are simulated and analyzed.The simulation results show that the bandwidth of the first MIMO antenna is 25.2?31.3GHz,theS₂₁ value is less than-21d B,and the gain range is 3.95?5.04d Bi;the bandwidth of the first array antenna is 27.4?30GHz,and the gain range is 7.99?10.17 d Bi.The bandwidth of the second MIMO antenna is 24.1?38GHz,theS₂₁ value is less than-19d B,and the gain range is 3.69?7.51d Bi;the bandwidth of the second array antenna is 24.3?29.4GHz,and the gain range is 10.57?12.16d Bi.In this thesis,the four antennas designed are made in physical objects,and the performance parameters of the antenna bandwidth,isolation,gain,and radiation pattern are tested.The simulation and measured results are basically consistent,verifying the correctness of the designed antenna.