Research On Flexible Antenna With Nano-scale Nested Wrinkled Structure

With the development of microelectronics technology,flexible conformal antennas with flexible materials instead of hard materials as dielectric substrates have become an emerging hot research direction.The flexible antenna can not only conform well with the carrier,but also can be curled and unfolded to save storage space.At the same time,the antenna performance can be kept stable,which provides convenience for people's lives.The flexible antenna is easy to conformal with the curved surface,and it has a wide application prospects in biomedicine,intelligent wear,aerospace,military and other fields involving miniaturized electronic equipment.In this paper,a flexible antenna fed by coplanar waveguide is designed,fabricated by the technology of MEMS and tested.The main research contents can be summarized as follows:(1)Based on the basic theory of coplanar waveguide feed antenna,the structure of the antenna was simulated and designed in Ansys HFSS.The important parameters were simulated and optimized,and the structural deformation and stress/strain were analyzed.The effects of structural deformation and stress/strain on the antenna frequency characteristics and radiation characteristics were analyzed.The central frequency of the flexible antenna is 7.5GHz.The simulation results show that the center frequency of the antenna remains unchanged at 7.5 GHz and the radiation effect remains unchanged during the process of bending conformal and stretching deformation.(2)The preparation method and technological process of flexible antenna were studied,and the characteristics of different media substrates were discussed.The flexible antenna was fabricated based on the micro-mechanical technology of MEMS.By physically depositing a rigid copper film on polydimethylsiloxane(PDMS),first the surface of PDMS can be wrinkled by pre-stretching treatment and surface modification treatment,and then the secondary wrinkle of PDMS surface is caused by heat treatment when the copper film is deposited.A flexible antenna with wrinkled PDMS surface is developed.The purpose of PDMS surface wrinkling is that the rigid copper film on the surface of the deformed antenna will not crack.(3)The performance of the antenna under bending/stretching was tested.The test results show that the test results are the same as the simulation results in both bending and stretching processes.The return loss curve remains unchanged,the center frequency of the antenna remains stable around 7.5GHz,and the radiation direction is not affected.The flexibility test shows that the flexible antenna maintains stable performance and can be recovered.The flexibility can reach 360 degrees and the tension can reach 40%.In view of the development demand of flexible antenna,this paper explores the design and implementation methods of flexible antenna,provides the corresponding solution for the conformal design of flexible antenna,and provides a reference for the integration of antenna and electronic equipment.