Research On Space Electromagnetic Protection Technology Of Airborne Rf Equipment Based On Energy Selective Surface

The damage effect of high-power microwave on electronic equipment is mainly reflected in the burning of electronic components and internal chips.Such an effect may result in unstable or inoperable operation of the electronic system.The energy-selective surface(ESS),as a means of spatial electromagnetic field protection,has the characteristic of "allowing electromagnetic waves to pass through within the safety threshold and automatically reject electromagnetic waves passing above the safety threshold",that is,having "energy adaptive switching characteristics".It can effectively prevent strong electromagnetic pulse from causing damage to the equipment and has little impact on the normal operation of the equipment.It is a new and effective means to ensure space electromagnetic safety.The specific research work of this paper is as follows:First,investigate the compatibility conditions between strong electromagnetic environment and electronic equipment.Because of the need for electromagnetic protection of the on-board electronic equipment,it is necessary to first understand the approximate RF sensitivity of the equipment to be protected and the field strength information of common interference electromagnetic waves as a reference indicator in the test process.Second,select the diode model and get its equivalent circuit for subsequent simulation.Then,the shielding characteristics of different unit structures are analyzed.Moreover,it is necessary to analyze the influence of each structural parameter in different ESS units on the insertion loss,isolation and bandwidth,and the influence of the electromagnetic wave polarization mode and the incident angle on the energy selective surface transmission coefficient.This provides a simulation basis for designing an electromagnetic energy selective surface with excellent performance.Then,summarizing the design rules of the previous article,and designing two ESSs of different frequency bands and different bandwidths according to the frequency bands of the airborne communication antenna and the GPS antenna,which can be used for the antenna cover of the two types of antennas,and play an electromagnetic protection role.The object is then produced and tested according to the designed ESS structure.From the perspective of physical testing,the ESS protection performance is studied,and the horn diameter protection experiment is designed to verify the energy low-pass protection performance of ESS,which proves the practical value of the designed structure.The insertion loss requirement of the ESS is less than 3dB(useful signal pass rate),the shielding effectiveness is greater than 30 dB,and the incident angle is not more than 45 degrees.