Design Of Multi Beam Antenna For Building Covered Micro Base Station

In recent years,mobile communication technology has developed rapidly.With the popularity of various intelligent terminals,mobile data traffic will show explosive growth after 2020.In this context,the 5th generation mobile communication(5G)with larger system capacity and higher transmission rate emerges as the times require.However,due to the high frequency,short wavelength and weak diffraction ability of 5G signal,when encountering obstacles,the signal will be greatly depleted.In addition,with the rapid development of urbanization in China,more and more high-rise buildings are springing up,and the height and density of buildings are constantly increasing.Therefore,in areas where buildings are concentrated,it is easy to cause poor signal quality,uneven signal coverage and poor data transmission.Therefore,relying solely on macro base stations can not meet the needs of all scenarios.The use of micro base station equipment with higher integration,smaller size and faster network construction has become an important development direction of network construction.For the simple buildings such as high-rise residential buildings,because a large number of indoor micro base stations are installed for indoor coverage,which is easy to cause obstruction to the owners,the method of outdoor coverage of the indoor is given priority,that is,to cover the indoor buildings from the outside through the outdoor micro base stations.Outdoor micro base stations have many advantages,such as small size,small weight,flexible installation,low transmission power consumption and support for multiple ways of connection.Therefore,they can be used as an effective supplement to macro base stations,and can effectively improve the quality of network services and three-dimensional coverage effect.Therefore,they have become one of the important means to solve the problem of indoor coverage quality.Antenna is an important part of micro base station equipment.Multi beam antenna can cover many buildings at the same time,which can reduce the number of antennas and the coupling and interference between antennas.Therefore,the design of multi beam antenna for micro base station has important research and application value.Two kinds of multi beam antennas are designed in this paper.The first one is a three-beam antenna applied in 5G band.The design method is to use dipole antenna as radiation source and place three split ring resonators around the dipole antenna.Each split ring resonators is on a plane with the dipole antenna.The angle between the two of the three split ring resonators can be adjusted according to the radiation direction.The electromagnetic field distribution around the dipole antenna can be changed by three split ring resonators,and finally three directional beams with the required angle can be formed.HFSS14.0 electromagnetic software is used to simulate and optimize the antenna parameters.After obtaining the simulation results,the antenna is processed and tested.The test results show that the antenna parameters basically meet the design requirements.The second one is an adjustable multi beam antenna applied in 5G band.The design method is to use monopole antenna as radiation source and place six frequency selective reflectors around the monopole antenna to form a hexagonal prism.The frequency selective reflector and monopole antenna are vertical to the ground plate.The RF switch designed by diodes,resistors,capacitors and inductors controls the on-off of each frequency selective reflector and ground plate.By changing the on-off of each frequency selective reflector,the number and direction of radiated beams of the antenna are changed,and the adjustable multi beam antenna is realized.HFSS14.0 electromagnetic software is used to simulate and optimize the antenna parameters.After obtaining the simulation results,the antenna is processed and tested.The test results show that the antenna parameters basically meet the design requirements under different modes.