Study On Multimode Micro-Base Station Antenna

In recent years,mobile communication technology has developed rapidly,and the access volume of mobile terminals has increased.This has placed higher demands on the capacity and data transmission rate of the entire system.As a complement to the traditional base station,the micro-base station has gained more attention due to its advantages of small size,low cost,and ease of installation,and the antenna is an indispensable component in the micro-base station.Due to the continuous changes in multi-generation communication technologies,there are more and more requirements for micro-base station antennas,such as broadband,miniaturization,and multi-polarization.In order to meet the simultaneous application of multiple generation technologies,the integration of micro-base station antennas is required.It is necessary to ensure that the antenna elements have good performance of compact structure and weak coupling between adjacent elements.This paper focuses on the micro-base station antenna for broadband,multi-beam and integrated application.The main work is as follows:1.Research on broadband dual-polarization micro-base station antennas.The antenna is based on microstrip antenna.The method of capacitive probe coupling feeding and the parasitic patch loading are employed to broaden the bandwidth of the antenna.Then,in order to improve the isolation between the dual-polarized antenna ports,the patch antenna is fed in the form of a four-point differential feed,and a broadband feed network is designed for this purpose.Finally,the antenna can reach the return loss of both input ports greater than 15 d B and the isolation is greater than 40 d B over the frequency range of 1.88 GHz to 2.69 GHz.2.Research on broadband multi-beam feed networks.A wideband dual-beam feed network within 1.88 GHz to 2.69 GHz is designed for the above-mentioned broadband dual-polarization micro-base station antenna unit.It can realize two symmetrical beams.When port 1 or port 2 is excited,the phase between the three output ports is advanced or delayed by 120°±3°.The components include a wideband 90° bridge,a wideband 180° bridge,and a broadband 2:1 splitter,which are then combined to design the feed network.Finally,the designed broadband dual-polarized antenna is arrayed and fed by the broadband dual-beam feeding network to form two symmetrical patterns with a maximum radiation direction of ±27°±5°.3.Research on multi-antenna integration technology.Firstly,a millimeter-wave antenna array is designed in the form of microstrip antenna.The feed adopts a series-parallel combination method to realize a bandwidth with the return loss greater than 10 d B in the 27.5GHz to 28.5GHz band,and the gain is greater than 16 d B.Then,based on the above-mentioned broadband dual-polarized antenna unit,the metal of the upper microstrip patch is multiplexed as a high-frequency antenna floor,and the feed of the high-frequency antenna is passed through the center of the patch to the bottom of the floor,which achieves the common aperture and integration of the high and low frequency antennas.The antenna operating frequency band is 1.88GHz~2.69 GHz and 27.5GHz~28.5GHz,which can cover the communication bands of 3G,4G and 5G.