Research And Design Of Multi-beam Antennas In The Mobile Communication Base Station

At present,the 4G(the fourth generation mobile communication system)has been put into commercial use on a large scale,the research of the 5G is in full swing.The contradiction between the increasing number of mobile communication users and the shortage of base station site resources runs through the whole process of the long term evolution of the mobile communication system.Nowadays,the 2G,3G and 4G systems form a long term co-existence situation,How to make the antenna play a better role in the existing network is crucial.Multi-beam antenna,which is a high-profile technology of expansion,has a good application prospect and research significance in the field of base station antenna.Based on the above background,in this paper,the application research and design of multi-beam antenna for mobile communication are carried out.First of all,in this paper,the development of multi-beam antenna technologies is summarized and the key technologies of multi-beam antenna are analyzed.On this basis,the Butler matrix feed network is selected as the main technology for the design of multi-beam antenna.Then,according to the actual demand of mobile communication service,the paper sets the Penta-Beam antenna as the main part of this study and sums up its basic principles.Then,the Penta-Beam base station antenna which is working at 1710~2170MHz(suitable for the 2G and 3G systems),is studied in this paper.The research includes the following aspects: 1)In this paper,the array from of antenna was analyzed: Though theoretical calculation and simulation,the formation of horizontal and vertical plane array was determined.then,a 6x10 array antenna was formed as Penta-Beam antenna.in order to improve the radiation performance,the form of the array was optimized.2)After specifying the array form of the antenna,a method about 5x10 Butler matrix that can realize the beam forming on the horizontal plane was proposed.the 5x10 Butler can be composed of two pieces of 3x5 Butler matrix and a pieces of 5x6 Butler matrix.Base on the method,I creatively designed two kind of 3x3 Butler matrices with different topological structures: coupled form 3x3 Butler matrices and hybrid form 3x3 Butler matrices.3)What is more,after comparative analysis,the coupled form 3x3 Butler matrices was chose and expanded to the 3x5 Butler matrix.And I designed a adaptive 5x6 Butler matrix.those two kinds of matrixes combined into 5x10 Butler matrix network which can make the antenna radiated five beams that are on demand.4)In order to realize the beam forming on the vertical plane of the Penta-Beam antenna,a 1to6 power splitter was designed,which causes the vertical plane of the antenna beam to have a fixed inclination angle and obtain low side-lobe.Finally,chose the above 5x6 Butler matrix,3x5 Butler matrix,1 to 6 power splitter and the antenna array to make into material object and assemble into Penta-Beam antenna.The measured result of the pattern of the antenna agree with the simulation results,meeting the designing requirement and the actual use.