Research On Broadband Multi-port Feeding Network For Multi-beam Base Station Antenna

With the rapid development of mobile Internet,the shortage of station and spectrum resources in the wireless communication system makes the application of multi-beam base station antenna more and more widely in the field of communication technology.Multibeam base-station antennas by butler matrix network radiation from different point of the beam,so as to make the antenna signal in a broader range of at the same time,also has improved network capacity,truly realized the existing spectrum and site under the condition of shortage of resources,effectively solve the antenna system capacity is insufficient,the lack of cover depth.Therefore,in recent years,the research of Butler matrix network based on wide band and multi-beam has attracted extensive attention.The work content of this paper includes the following aspects:(1)The design ideas of 3×3 Butler matrix network and small 5×6 Butler matrix network with working frequency range of 1710 MHz to 2690 MHz are innovatively proposed.In the design of the above matrix network,strip lines are selected as transmission lines and fixed phase shifters are adopted as basic components.The small 5×6 Butler matrix network is composed of two 2×2 Butler matrix networks with different topologies and a one part two network,respectively.The test results show that the standing wave ratio of the input ports of the 3×3 Butler matrix network and the small 5×6 Butler matrix network is less than 1.3 and the isolation degree between the input ports is greater than 20 dB,which is consistent with the simulation results.(2)A new 5×6 Butler matrix network with 1710 MHz-2690 MHz as the operating frequency band is proposed to meet the requirements of horizontal plane beam configuration of five-beam base station antenna.When the signal is fed to any of the input ports,the amplitude of the output signal from the six output ports is uniform,and there is a specific phase difference between each of the two adjacent output ports.The test results are consistent with the simulation results.The standing-wave ratio of the input ports of the new 5×6 Butler matrix network is less than 1.4,the isolation degree between the input ports is greater than 20 dB,and the isolation degree between the output ports is greater than 25 dB.Compared with the traditional 5×6 Butler matrix network,the design structure of this network is simple,and the antenna miniaturization is realized.At the same time,the design can reduce the error in the antenna assembly process,and has a good performance.(3)An integral shape-forming network of five-beam base station antenna is proposed,which can radiate five directions of-30°?-15° and 0°respectively.The 15° and 30° sub-beams meet the network configuration requirements of the five-beam base station antenna,and the gain of each sub-beam is greater than 21dBi.The beam width converges and the deviation of the vertical plane inclination of the antenna is less than 1°,which meets the index requirements.