Research On Design And Characteristics Of Microstrip Patch Antenna Decoupling Structure

In the background of 5G communication era,compared with a single antenna,it has been unable to meet the increasing performance requirements of the antenna,and due to the integration and miniaturization of mobile terminals,the antenna spacing is gradually reduced,which aggravates the mutual coupling problem between the antennas,thus affecting the performance of the whole wireless communication system.Therefore,it is very important to analyze the coupling characteristics between antennas with different spacing,and design the corresponding decoupling structure by using the decoupling method reasonably in a limited space,which provides a reference for 5G communication system.Based on the above problems,this paper focuses on the analysis of the coupling characteristics of microstrip patch antenna and the design of decoupling structure,the specific work is as follows:1)According to the 5G communication band issued by the Ministry of industry and information technology,a side fed microstrip patch antenna with a working frequency of 4.85 GHz is designed in this paper.The simulation results show that the matching bandwidth of the antenna is 190 MHz at-10 d B,and it has good radiation efficiency.Based on this antenna,the array antennas with different side to side spacing are formed,and the strong mutual coupling effect between closely adjacent antennas is analyzed and discussed.With the decrease of antenna spacing,the mutual coupling effect between antennas becomes more and more strong,and the radiation efficiency and the isolation degree of receiving and transmitting are seriously affected.2)Taking the dual element microstrip patch antenna array as an example,a Z-type decoupling structure based on the field cancellation method is designed when the distance between two antennas is 10 mm.The simulation results show that the structure can effectively improve the isolation between the two antennas with 4.85 GHz as the center working frequency point,and achieve the purpose of restraining the coupling,and the isolation can reach 54 d B under-10 d B working bandwidth(190MHz).3)Furthermore,the distance between the two antennas is further reduced to 2mm,and a T-type decoupling structure based on the field cancellation method is designed to form an indirect coupling field between the antennas,so as to cancel the direct coupling field between the antennas.The simulation results show that at 4.85 GHz,the decoupling structure can make the antenna array achieve 190MHz-10 d B matching bandwidth,and the maximum isolation degree is 36 d B at 4.85 GHz,which effectively improves the isolation degree between the antennas.