Design And Fabrication Of Flexible RF Microstrip Line Based On DGS Structure

In recent years,stretchable flexible electronic technology has been widely used in the realization of wearable devices,reconfigurable devices and other new electronic devices.As an important part of electronic system,the flexibility of RF circuit is an significant part to expand the application of flexible electronics.Microstrip structure is one of the most considerable structures in RF microwave circuits.The realization of stretchable flexible microstrip structure can effectively promote the development of flexible RF circuits.However,the ground plane structure of traditional microstrip structure is not malleable,so it is difficult to realize flexible microstrip structure only by changing the conduction band structure.Therefore,it is of great significance to explore and realize the application of RF microstrip line in stretchable electronic system with the core of stretchable flexible design of microstrip structure ground plane.This paper is based on DGS（Defected Ground Structure）.The electrical properties of the RF microstrip line are simulated by HFSS,ADS and txline to obtain the S parameters of the microstrip line.The mechanical properties of the microstrip line are simulated by ABAQUS to gain the stress-strain distribution and curves.The mechanical and electrical properties of the flexible RF microstrip line are tested by experiments.The main contents of this paper are as follows:1.The basic electromagnetic characteristics of DGS structure are analyzed.Among them,the application of DGS filter characteristics in microstrip ground plane design is mainly discussed.2.Combined with the design idea of periodic grid and electromagnetic calculation software,the flexible RF microstrip lines with different DGS structures are designed.The results of electromagnetic simulation show that the microstrip line has good out of band suppression capability as well as practical application value in L and S band.The S parameters of the flexible RF microstrip line are tested under different tensile conditions by using vector network analyzer and in-situ stretching platform,which verifies the performance stability of the flexible RF microstrip line in the event of large deformation.The results show that the DGS flexible RF microstrip line is S₁₁<-10d B and S₂₁>-3d B in the frequency range of 0-5GHz;The rate of change of 3d B cutoff frequency is not more than 2%when the tensile ratio is 30%.3.Based on the calculation and experimental results,the relationship between the structure parameters of DGS and the performance of flexible RF microstrip line is analyzed,and the physical model of DGS flexible RF microstrip line is established.Combined with the model,the coupling characteristics between the mechanical and electrical properties of the flexible RF microstrip line are researched.