Design Of Broadband Dual-polarized Based Station Antennas For Mobile Communication

With the development of mobile communication technology,increasing traffic volume and diversified communication services have put forward higher requirements for the performance of mobile communication systems.The base station antenna has an important role in mobile communication systems,and it directly affects the performance of communication device.The development direction of base station antennas must be adapted to the needs of mobile communication systems.Antennas are developing in the direction of miniaturization and broadband under the need of multi-system co-station and coexistence of multiple systems.Therefor,it is obviously significant that antennas can be compatible with multiple communication frequency bands.The main work of this thesis is focused on the broadband of the base station antennas.Based on the development direction of mobile communication base station antennas,two broadband dual-polarized base station antennas suitable for mobile communication systems were proposed.They are the broadband dual-polarized base station antenna unit applied in the 2G/3G/LTE/5G and the diamond-shaped broadband dual-polarized base station antenna unit applied in the IMT/2G/3G/LTE,and the latter antenna was arrayed.The main contents of this research topic are as follows:Firstly,we studied a wideband dual-polarization base station antenna covering 2G(1710MHz-1920MHz)/3G(1880MHz-2170MHz)/LTE(2300MHz-2400MHz&2570MHz-2690MHz)/5G(3300MHz-3600MHz)band.The broadband dual-polarization base station antenna is proposed to solve the problem of narrow bandwidth of existing base station antennas.A stable pattern and gain are achieved simultaneously in the entire operating band.In this paper,the resonance of the half-wave dipole is studied.To increase a new resonance mode,the U-shaped slots are introduced.The bandwidth is widened by improving the shape of the edges of the antenna and etching the U-shaped slots.Secondly,we studied a wideband dual-polarization base station antenna covering 2G/3G/LTE/IMT band.The antenna is proposed to solve the problem of narrow bandwidth and non-planar of base station antennas.A stable pattern and gain are achieved simultaneously in the entire operating band.The antenna uses an arc-shaped radiating structure to change the current path.It can realize impedance matching through the balun feed to widen the frequency band of the antenna.Concentrating domestic and foreign frequency bands on antenna unit can overcome the shortcomings of building base station antenna separately.The antenna has a simple and stable structure and the compact shape is easy for mass production.The printed dipoles are used as dual-polarized antenna element greatly reduces the installation steps.Thirdly,We studied the broadband dual-polarized base station antenna array covering the 2G/3G/LTE/IMT frequency band.The antenna array is composed of four antenna elements with the same structure and placed on the metal reflector.The distance between the antenna elements is equal.To validate the proposed antenna,a prototype has been fabricated.The measured results and the simulation results are basically the same.The results show that the antenna array can cover the whole frequency band.For the proposed antenna,the relative bandwidth is 72.9%.The antenna achieves stable gain and half power beam width in the operating band.