Design Of Electromagnetic Wave Manipulating Devices Based On Phase Change Material

The design of the electromagnetic(EM) waves control devices has always been a hot topic in the field of electromagnetism.Traditional EM waves manipulating devices(such as prisms and gratings)usually have bulky volume and high loss.It is difficult to achieve planarization and miniaturization by relying on the gradual phase changes accumulated along the transmission path to manipulate EM waves.In view of this,the metasurface unit structures loaded with phase change material(PCM)come into being.The PCM has phase change characteristic and could realize MetalInsulator Transition(MIT).By designing the metasurface unit structures loaded with PCM reasonably,the multi-manipulating of the polarization conversion mode will be realized.And it will break the volume limit by introducing abrupt phase changes at the interface and improve the practicality and integration of devices.However,the transmissive artificial EM surface is still facing the problem of cross-polarization conversion efficiency is too low to meet the engineering needs.In this paper,the phase transition characteristics of the PCM and the metamaterial theory will be used to design a periodic metasurface to control the polarization conversion of EM waves,which could achieve manual manipulation of EM waves polarization and lead to a wonderfull prospect in engineering application based on discontinuous phase metasurface.Firstly,the research is focused on the study of high efficiency metasurface units,and the method of realizing high cross-polarization conversion rate is discussed.A new type of EM waves manual manipulating metasurface loading with VO2 is designed and magnetic resonance is introduced to improve the cross-polarization conversion efficiency.Secondly,based on the high efficiency metasurface unit,the wave-plate conversion units by loading with the VO2 are designed,which are part of the quarterwave plate metasurface and the half-wave plate metasurface.The microstrip antenna is used to verify them through the computer simulation.The simulation results show that the phase transition characteristics of the PCM can realize the multi-manipulation of the polarization conversion mode.Meanwhile,high efficiency of cross-polarization conversion and the ultrathin property with respect to wavelength are both realized,which makes the EM waves manipulating devices more suitable for practical applications.