Research On Wide-band And Wide-angle Scanning Technology Of One-dimensional Phased Array Antenna For 5G Applications

With the development of modern wireless communication technology,the application of 5G communication is also increasing,but the communication systems of2 G,3G,and 4G will inevitably exist for a long time at the same time,which will increase the demand for multi-frequency and broadband antennas.The research direction of phased array has been inclined to realize wide-band and wide-angle scan in order to make wireless communication more compact,more functional and better performance.Due to strong electromagnetic coupling between the elements,the tightly coupled antenna can expand the bandwidth and cover many working frequency bands,so it has become the preferred broadband antenna.Based on the requirements of scientific research projects,the main content of this thesis is to study and design the one-dimensional phased array antenna applied to 5G in the form of tight-coupled dipole antenna.The main contents of this article are as follows:Firstly,the structure of the phased array and the scanning principle of the onedimensional phased array antenna are introduced,and the principle of the strong coupling broadband is analyzed with the Smith Chart,which provides the theoretical basis for the following designSecondly,based on the tightly coupled antenna theory,a one-dimensional dualpolarized phased array with a planar structure is designed.And the elements are arranged along the horizontal polarization,working at 3.3?6GHz,focusing on 3.3?3.8GHz and5.4?6GHz two frequency bands.To maximize the aperture efficiency of the array,the sub-element contains multiple dipoles and are fed directly through coaxial line.In addition,the impedance matching and wide-angle scanning performance of the unit are optimized by using structures such as elliptical metal patches,metal block structures and matching layers.When the antenna scans to 60°,most of the two polarized active standing waves in the operating frequency band are less than 3,and the isolation is more than 15 d B.In order to further verify the accuracy of the design,a 1 × 19 finite array is fabricated and tested,and then compared with the simulation results.Finally,in order to further increase the isolation of the dual-polarized port,a tightly coupled phased array with a vertical structure is designed.In order to reduce the number of T/R modules and get closer to the actual working state,the antenna unit and power splitter structure are simulated.The low-frequency unit is composed of three sub-units,and the high-frequency unit is composed of two sub-units,which are fed by equalamplitude and same-phase power dividers and work in the frequency bands of 3.3?3.8GHz and 5.4?5.95 GHz,respectively.After the simulation of the single-polarization antenna,the dual-polarization element is designed,and the important parameters are analyzed.After optimization,the maximum standing wave of high-frequency and lowfrequency units is 3.2,and the isolation is greater than 30 d B.By extending the outermost dipole length to reduce the effect of truncation effects,a 1×24 finite array is simulated and the performance of each element is analyzed.