Research On Decoupling Technology For High Density Base Station Antenna

As the new generation of mobile communication system enters the 5G era,higher requirements are put forward to the channel capacity and communication speed of mobile communication system,which requires continuous development and innovation at all aspects of the whole mobile communication system.As for the base station antenna,it is obvious that there is a contradiction between the increasing channel capacity and highspeed communication demand of mobile communication system and the need for antenna have lesser space occupy and lower cost in reality.In order to figure out the problem,dual-polarization high-density MIMO base station antenna becomes the preferred alternative,because large-scale MIMO antenna can solve the problem of insufficient channel capacity,and miniaturized antenna element and more compact antenna layout can meet the requirements of smaller footprint and lower cost.Demand for base station antenna in modern communication system,this dissertation mainly around highly density base station antenna decoupling technology,exploration and design more practical and electrical size smaller base station antenna,research the coupling condition in a more tightly base station antenna array,and put forward a feasible plan for decoupling in high density MIMO antenna array at a complex electromagnetic environment.To meet the engineering needs,this thesis focuses on the research high-density base station antenna decoupling technology.The main work of this thesis can be summarized as follows:Firstly,two kinds of ±45° dual polarization base station antennas which can operate at 1.7-2.7 GHz are proposed.In this work,a traditional size base station antenna and a miniaturized base station antenna are designed.Both antennas use the introduced ring resonator to expand the impedance bandwidth of the base station antenna at high frequency,and the ring resonator is also the radiation patch of the antenna in the crosspolarization direction of the antenna,and finally achieve the working bandwidth of 1.7-2.7GHz and double polarization of ±45°.Compared with traditional base station antennas,the designed miniaturized base station antenna has a 40% reduction in the aperture area,and a gain of 8 d B±0.3 d B,a 3 d B beamwidth of 70°±1°,and a 10 d B beamwidth of127°±2°,indicating a more stable radiation pattern at 1.7-2.7GHz.Finally,the two base station antennas are fabricated and tested,and the performance of the proposed two base station antennas is verified.In addition,two 2×2 MIMO arrays are formed by the two kinds of base station antennas above,which verifies that the proposed miniaturized base station antennas can reduce the negative effects caused by coupling.The row spacing and column spacing between the antennas in the two arrays are 80mm(0.45?,? is the wavelength at 1.7 GHz),and the two 2×2 MIMO arrays can work at 1.7-2.7 GHz.Compared with the traditional MIMO array,the radiation pattern distortion of the MIMO array composed of miniaturized base station antennas is significantly reduced,and the port isolation degree between array elements is 1-3 d B higher.Finally,the prototype of traditional MIMO antenna array and miniaturized MIMO antenna array of 2×2 array are fabricated,assembled and tested.The test results are in good agreement with the simulation results,which fully proves that the miniaturized base station antenna can reduce the coupling between array element.