5G Communication Array Antenna Applied To Sub10 GHz

As the Sub10 GHz frequency band is put on the agenda at the World Wireless Communications Conference,research on base station antennas in this frequency band is imminent.With the increasing improvement of communication capabilities,the miniaturization,low coupling and large-scale coverage of base station antennas in the future are the objects that need to be focused on.In this research,the following studies are carried out on array antennas with wide-area beam coverage:1.Applied to the research of Sub10 GHz frequency band communication array antenna unit and line array.Firstly,a wide bandwidth beam±45°dual linearly polarized dipole antenna element is designed.The beam is relatively wider by selecting elliptical patches and a larger ground plane;the impedance bandwidth is broadened by digging holes in the patch and other improvements.It can be seen from the measured results that the reflection coefficients in the frequency band of 5.6-7.6 GHz are all lower than-15 d B;the isolation in the frequency band is higher than 28 d B,the average gain is about 6.46 d Bi,the 3 d B beam width is about 127.2°,and the crossover is about 127.2°.The polarization ratio is21.6 d B.Secondly,a wide-beam±45°dual linearly polarized microstrip antenna unit is designed.The beam broadening is achieved by loading metal pillars and fan-shaped parasitic patches;the impedance bandwidth is broadened by loading the upper parasitic patches.It can be seen from the simulation results that the reflection coefficients in the frequency band of 6.36-7.03 GHz are all lower than-10 d B;the in-band average gain is5.3 d Bi,the beam width of the H-plane pattern is 122.7°,the cross-polarization ratio is27.1 d B,and the E-plane pattern beam width is 130.9°and the cross-polarization ratio is20.4 d B.The dipole antenna elements are formed into a 1×16 uniform linear array,and the array element spacing is selected as 0.53λ₀.The simulation results show that the beam width of each element in the array is greater than 130°;when the main beam gain drops less than 3 d Bi,the array beam can scan to a maximum angle of±55°;when the main beam gain drops less than 5 d Bi,the array beam can scan maximum angle is±60°;the side lobe level is lower than 9.2 d B,and the cross-polarization ratio is more than 15 d B.2.Research on decoupling and wide-angle scanning of area arrays.The mutual coupling between the elements of the antenna array will lead to the decrease of antenna gain,side lobes and the efficiency under large scanning angles.Therefore,it is of great significance to study how to reduce the mutual coupling of the array to realize wide-angle scanning.Firstly,the different layout methods（uniform distribution,symmetrical rotation distribution and symmetrical rotation dislocation distribution）are studied.Among them,the symmetrical rotation distribution improves the isolation by 2 d B,and the symmetrical rotation dislocation distribution improves the isolation by 4 d B;then the floor is used.Slitting and loading parasitic structures improve the array structure.The simulation results show that the floor opening improves the isolation by 4 d B,and loading the parasitic structure improves the isolation by 6 d B.The research on the dipole antenna array shows that with the increase of the number of array elements,the maximum scanning angle of the array increases when the main beam gain decreases by 3 d Bi,but at the same time the coupling and polarization isolation between the array elements deteriorate.The wide-angle scanning of the microstrip antenna unit is carried out.Due to the metal pillars between the array elements,the coupling and polarization isolation between the array elements are improved.When the scanning angle reaches 60°,the cross-polarization ratio is still at 15 d B or more.3.Research on the large-scale coverage of the three-dimensional array.Firstly,the brainstorming algorithm and its improvement are analyzed.Next,the triangular pyramid array composed of area arrays is studied,which can achieve 360°coverage radiation on the azimuth plane and±120°coverage radiation on the elevation plane.Then,the improved brainstorming algorithm is used to form the beamforming of the stereo array,and the beamforming research is carried out on the azimuth plane,the elevation plane and the diagonal direction respectively.The simulation results show that each area array can achieve a beam coverage of±60°in the azimuth and elevation planes,and the gain in the maximum scanning direction is above 12 d Bi;The side lobe level is still lower than-9 d B during the maximum scanning in the azimuth plane,and the side lobe level is still lower than-6 d B during the maximum scanning in the elevation plane,the nulls are all above 20 d B,and the cross-polarization ratios are all higher than 14 dB.