The Design Of MIMO Antenna System For Mobile Terminal

With the rapid development of wireless communication technology and the increasing demand For wireless communication,wireless communication network is developing rapidly in the direction of high speed,large capacity and low latency.The emergence of MIMO(Multiple-Input Multiple-Output)technology improves the communication rate and system capacity of traditional communication technology,and has gradually become the core communication technology.So MIMO antenna technology has always been a hot research,and people have been working to achieve more units,higher isolation,smaller size,and higher performance of the MIMO antenna system.In the MIMO antenna system,the isolation between cell antennas and the size of the system have always been a difficult problem.In this thesis,based on the microstrip inverted F antenna,the MIMO antenna system of four units and eight units is designed,and on the basis of the inverted F antenna,a multi unit MIMO antenna system with space stereoscopic inverted F antenna(3D-IFA)as the unit antenna is designed.The main innovations and designs of this article are as follows:(1)The MIMO antenna system with a size of 150mm×75mm×1mm based on inverted F antenna and the MIMO antenna system with a size of 270mm×190mm×1mm are proposed in this thesis.They are printed antennas which can be used in handheld mobile terminals such as mobile phones and tablets.Application of these two multi unit MIMO antenna system including the frequency band used in the China Mobile TD band(2300-2400MHz),application of band ISM wireless network(2450MHz).(2)A multi band antenna with space stereoscopic structure(3D-IFAs)is designed.Based on this antenna,we design several multi unit MIMO antenna system components.The-6dB bandwidth of the system is very wide,which is1650-4000 MHz,which can cover application band PCS1900,UMTS2100,LTE2300,LTE2500,DCS1800,ISM and Future 5G communication LTE band.(3)The antenna system designed in this thesis adopts different decoupling structure to increase the isolation degree of MIMO antenna system.Two MIMO antenna systems are designed on the basis of the multi band antenna with spatial structure,and the parameters affecting the performance of the antenna are analyzed and studied.The antenna we designed can achieve multi band,high gain and other advantages to meet future communication needs.