Design And Application Of Electromagnetic Energy Protective Surface

With the rapid development of electromagnetic pulse technology,the threat of electromagnetic pulse to electronic equipment is becoming more and more serious.Energy Selective Surface(ESS)is a passive electromagnetic pulse protection structure based on Frequency Selective Surface.It can isolate high-power microwave pulses,through lowenergy electromagnetic signals,and achieve adaptive limiting effect on high-power microwave radiation field.It can effectively solve the compatibility between receiving radiofrequency electromagnetic signals and high-power microwave protection.This paper introduced the protection principle of energy-selective surface,explored the design elements of energy-selective surface and related problems in engineering application.Two types of energy selective surface,band-stop and band-pass was designed,and the feasibility of the application is verified by simulation and experiment.The first part mainly analyzed the protection principle of energy selective surface.Firstly,the working principle and some basic characteristics of frequency selective surface were briefly introduced.Then,based on frequency selective surface,energy selective surface was introduced.The working principle of band-stop and band-pass energy selective surface was analyzed,and the evaluation index of its protective performance was given,which points out the direction for the following research.The second part studied PIN diode which applied to energy selective surfaces.The working characteristics of PIN diodes under DC and AC(low frequency)conditions were analyzed based on the distribution characteristics of the diode carrier.The steady-state equivalent circuit models of PIN diode under the conduction and non-conduction were given.Then,the characteristics of PIN diode under microwave condition were studied by theory and experiment.The conduction principle of PIN diode under microwave condition was introduced.The microwave impedance,start-up threshold,response speed and the maximum endurance power of PIN diode were analyzed,which established a foundation for the design and performance analysis of energy-selective surface.In the third part,the design and experiment of band-stop energy selective surface were studied.Firstly,the influence of the parameters such as dielectric constant of dielectric material,unit structure and size,equivalent parameters of PIN diode and incident angle of electromagnetic wave to band-stop energy-selective surface on the transmission characteristics were analyzed.Based on the research of PIN diode,the start-up field,response speed and high frequency applicability of band-stop energy selective surface were discussed.Then,combined with the engineering application scenarios,the influence of the total size of the energy selective surface on the transmission characteristics was studied,and the spatial field distribution near the energy selective surface in this application scenario and its influence to the start-up field were analyzed.Finally,an experiment sample of band-stop energy selective surface was designed and manufactured,and the protective performance was tested under high power microwave,which verified the feasibility of its protective application.The fourth part mainly studied the design of band-pass energy selective surface.The influence on performance in different unit structure,different unit size and equivalent parameters of PIN diode to band-pass energy selective surface were studied.According to the research result,a band-pass energy selective surface for X-band was designed and its feasibility for high power microwave protection was analyzed.