Design And Research Of MIMO Antenna

With the rapid development of communication technology,antenna design has received more and more attention.The antenna is located at the forefront of the communication system.It is used to transmit and receive signals.To a certain extent,the performance of the whole communication system is determined by the antenna.Because MIMO antenna can greatly improve the capacity of communication channel and data transmission rate without loss of frequency bandwidth and transmission power,it has attracted much attention.Therefore,the design of multi-band MIMO antenna or ultra-wideband MIMO antenna can be applied in different frequency bands is of great significance.So this paper will focus on the design of multi-frequency MIMO antenna and ultra-wideband MIMO antenna.This thesis firstly briefly summarizes the research status and development trends of MIMO antennas and ultra-wideband antennas in recent years at home and abroad,and shortly introduces the UWB MIMO antenna and summarizes how to reduce the port isolation between MIMO antenna elements.Secondly,a miniaturized two-cell three-band MIMO antenna that can be applied to the WLAN/WiMAX band is designed.The antenna is designed on the FR4 substrate and three working frequency bands are generated by two orthogonally placed E-type monopole antenna elements.So that the antenna can operate at 2.45/3.5/5.2 GHz.The I-shaped branch on the ground acts as a reflector to reduce the port isolation of the two antenna elements to reduce the isolation of the antenna to below-15 dB over the operating frequency range.Thirdly,a compact notch ultra-wideband MIMO antenna is designed.The antenna is printed on the FR4 dielectric substrate and is composed of two identical antenna elements arranged orthogonally.The antenna unit is composed of a stepped rectangle,and is fed by a microstrip line.The rectangular open resonant ring is etched on the antenna unit to realize the function of trapping,and the electromagnetic interference between the wireless local area network WLAN(5.15 to 5.85 GHz)and the antenna system is solved;by increasing the isolation branch on the symmetry axis of the ground plane of the dielectric substrate,the port isolation is increased from-12dB to-16dB.