Study On The Key Technologies Of Small Spacing Array Antenna

With the rapid development of wireless communication technology,there are great improvements in message capacity and transmission rate of communication system in recent years.At the same time,the complexity of the system is becoming higher and higher.In particular,the number of antenna array is gradually increasing,which leads to the rise of the system cost and the scarcity of the space resources.It could be effective for reducing the port surface and volume of the antenna array by using small spacing array antenna.This thesis aims to realize the miniaturization of the antenna array,studying the key technologies of the small-spacing array antenna,incluing the research on the technology of small antenna and the decoupling technology between antenna elements with small spacing antenna array.The main contents of this thesis can be divided into the following parts:1.The miniaturization technology and wide beam technology of antenna unit is studied.Firstly,based on the radiation principle of microstrip antenna,a magnetic antenna element is constructed.The radiation pattern of the antenna shows that the half-power beamwidth in E-plane exceeds over 150°.In terms of size,the transverse size of the antenna is less than0.3(?) and the profile height is less than 0.1(?).The antenna unit has the characteristics of small size and wide beam.Then,based on the single polarization,a magnetic current antenna in the form of dual polarization is designed.At the same time,its wide beam radiation characteristics are maintained.Finally,the single polarization antenna elements are composed of one-dimensional linear array and two-dimensional planar array respectively.The simulation results show that wide Angle scanning of ±77° and ±72° are achieved in the E-plane respectively.2.The effect of AMC structure on the miniaturization and decoupling of antenna elements is studied.Firstly,the structure of AMC is briefly introduced,and its working principle is briefly analyzed.Secondly,taking the dual polarization dipole antenna as the research object,the profile of the dipole is reduced to only 0.07 (?) by using in-phase reflection characteristics of the AMC structure.What's more,according to the characteristic of band resistance of AMC structure for the propagation surface wave,the port isolation of the dual polarization antenna element in the two-array in the direction of collinear polarization is improved.Compared with the ground structure of ordinary conductor,the isolation between antenna with AMC structure is improved by 17 d B.3.The effect of parasitic resonant branch structure on enhancing port isolation between antenna elements is studied.Based on the principle of inverse elimination of the indirect coupling field,a ?-shaped metal branch is proposed to improve the isolation between antennas in dual polarization directions in a binary array.Furthermore,a coplanar waveguide microstrip line form of power splitter is designed,and the antenna elements are composed of a 3×3 MIMO antenna array.The VSWR of the array is less than 1.5 in the frequency band of 2.5GHz-2.7GHz,and the port isolation of each port is below 18 d B.The experimental results are in good agreement with the simulation results.As a result,the decoupling technology under small spacing array has been realized.