Decoupling Structure Design Of Microstrip Patch Antennas

The coupling and decoupling between adjacent antennas is an important subject in antenna design,and the coupling between antennas often has an unexpected impact on the performance of wireless communication systems.Generally,mutual coupling reduces the transmit and receive isolation of antennas,thus increasing the difficulty of receiver design for wireless communication systems.Therefore,the study of decoupling of adjacent antennas has important practical application value.In this paper,the design of decoupling structure of adjacent microstrip patch antenna is deeply studied by principle analysis and simulation.The main contributions of this dissertation are as follows:(1)Several coplanar decoupling structures based on field cancellation are designed to solve the problem of mutual coupling between closely spaced patch antennas.This kind of field-to-indirect decoupling structure adds an indirect coupling field between the antennas to offset it from the original direct coupling field,so that the purpose of suppressing the mutual coupling can be achieved.In this paper,the microstrip patch antenna decoupling structure is an example.HFSS simulation results show that when the microstrip antenna is placed tightly,their isolation can reach the minimum 25 dB at-10 dB bandwidth(100 MHz),and the isolation of this structure can reach the minimum 30 dB at 50 MHz bandwidth.An indirect decoupling structure based on defective structure is designed.It is a structure based on the development of electromagnetic bandgap structure,which can be filtered on the coupling path between microstrip antennas to achieve.The simulation results show that the isolation of the structure can reach the minimum 17.5dB at-10 d B matching bandwidth.(2)A variety of heterogeneous decoupling structures are designed,such as metal wall open channel structure,this structure not only can use the field but also be used in the middle of the PCB part to reduce the coupling between microstrip antenna to improve isolation.The simulation results show that the isolation of the structure can reach the minimum 21 d B.And also The decoupling structure of T-shaped symmetric metal strip is designed,the simulation results show that the isolation degree can reach the minimum 41.5dB at-10 dB matching bandwidth(80MHz).