Research On Dual-frequency Shared-aperture Base Station Antenna

With the significant advancement in modern mobile communications and the advent of 5G era,increased communication frequency leads to increased space loss,In order to ensure the effective coverage of communication signals,the number of base stations is bound to increase,at the same time,the space resources of base stations are increasingly limited,which makes the requirements for antenna performance of base stations increasingly high.How to accommodate more antennas under the limited space resources is an important issue in the current antenna design of base stations.The common method to solve this problem is to miniaturize the antenna and reduce the size of the antenna unit as much as possible so as to reduce the overall space occupied by the antenna.However,the advent of 5G era does not mean that the base station antennas of 4G frequency band and lower frequency band will be abandoned in the short term.In other words,the construction of the base station requires the antennas of different frequency bands to work simultaneously.If the antennas of different frequency bands are just simply arranged,the space resources occupied by the antennas will be increased,and at this time reducing the antenna unit size does not work well.In this case,deep spatial fusion of antenna elements of different frequency bands is of great significance for reducing the spatial size of antenna.A good candidate to solve the problem are shared aperture Antennas.The shared aperture antennas was suggested as a good choice for base station due to it can accommodate multiple antennas of different frequency bands or even different polarization in the same installation aperture.Therefore,the shared aperture Antennas can not only make the antennas of different frequency bands work without affecting each other at the same time,but also reduce the space occupied by the antenna significantly.In recent years,the obvious advantages described above have led to the demand of shared aperture antennas being increased in base station construction of wireless communication systems.It is of great practical significance to study the shared aperture antennas,so this paper focuses on the research of dual frequency shared aperture base station antenna.Firstly,this paper systematically summarizes the shared aperture antenna,and introduces several typical shared aperture antenna.Then two kinds of wide-beam antenna units that can be used for shared aperture antenna arrays and two kinds of dual-frequency shared aperture antennas are proposed in this paper.1.Two kinds of wide beam antennas are proposed and investigated in this paper.An additional vertical current is introduced by adding a parasitic metal structure around the antenna to increase the radiation capacity of the antenna in the horizontal direction,enhancing the 3d B beam width,The bandwidth is 42.1% for S11 <-15 d B,from 1.97 GHz to 3.02 GHz.Another wide-beam antenna extends the 3d B beam width by adding a rectangular patch between the dipole and the floor.It covers the frequency range of 3.3-3.6GHz for S11 <-15 d B.2.A dual-band shared aperture antenna is proposed for LTE frequency band(824–960 MHz and 1710–2690 MHz)in this paper.The radiation patches for the upper frequency and lower frequency are printed on the different faces of the same dielectric plate respectively.The configuration of the high-band antenna unit is a pair of vertically placed planar dipole that can achieve ±45°dual-polarized,which works at 1710-2690MHz(S11 <-10 d B).The radiating structure of the low-band antenna element is a rectangular patch with hollowedout in the middle,and a parasitic structure is introduced inside the radiating patch to expand the impedance bandwidth of the antenna,which works at 824-960MHz(S11 <-10 d B).3.A dual-band shared aperture base station antenna operating in C-band(3.3-3.6 GHz)and millimeter band(24.25-29.5 GHz)is designed.This shared aperture base station antenna belongs to the "three-dimensional vertical stacked distribution" in terms of spatial layout.The C-band antenna is not only ensure low-frequency radiation performance,but also serves as a band-pass frequency selection surface for the millimeter wave band.It is located directly above the millimeter wave antenna,which can ensure the radiation performance of the millimeter wave band antenna to the greatest extent.Millimeter wave band antennas form a4*4 array,the angle of scanning ranges up to ±46°.