Simulation,Mesurement And Protection Application Of Energy Selective Surface

With regards to high intensity electromagnetic(EM)pulse threats of an electronic system,the requirement of an effective EM protection of "front doors" becomes a con-cern and results in a new kind of EM design with a self-inducted/self-activated function.Since the design is related to a large number of and complicated field-circuit couplings,numerical investigation and measurement techniques with critical accuracy and stability becomes a challenge.In this work,a numerical investigation and experimental study of a typical self-activated design,energy selective surface(ESS),is carried out and application techniques are discussed.First,hybrid field-circuit simulation technique is utilized for transient investigations of ESS.Base on Hilbert transform and least square approximation,a simulation module for extracting causal impulse responses from band-limited frequency responses is devel-oped.The module is used for transient investigation of nonlinearly loaded EM structures and visualization of nonlinear scattering fields.For the first time,a constrained causal impulse response optimization technique is proposed and successful used for investiga-tion of EM problems with more than two hundreds nonlinear loads.Related reports are published on IEEE transactions on Electromagnetic Compatibility.Second,de-embedding techniques are employed for extracting frequency responses of semiconductor components.Based on the thru-reflect-line(TRL)technique,a simpli-fied thru-line(TL)calibration method is developed for measurement of lumped elements with two pins.Based on this,an advanced de-embedding fixture is designed with free soldering,non-destructive operations during the measurement.By comparison with TRL calibration,simulation and experimental results show that TL calibration is improved with fewer operations and broader frequency band.A related patent is submitted.After that,the nonlinear behaviors of both semiconductive components and ESS are measured.Three kinds of circuit stimuli,DC,bipolar rectangular pulse and continues wave,are applied for analyzing the components' switch efficiency with considerations of ESS applications.For measurement of limiting thresholds in high frequency,an au-tomatic frequency/power sweeping system is build up based on Standard Commands for Programmable Instruments operating in L/S band.The time cost for single frequency or power sweeping is about 0.6 s.The maximum output power is up to 48.5 dBm.Three pieces of ESS prototype are fabricated and measured by three different free-space exper-iment setups.Results show that using the setup based on absorbing cavity gains good performances with regards to accuracy,large dynamic range and wide frequency band of measurement.For the first time,the self-activated protection of ESS is explored in free space at L-band.The transition threshold is around 1000 V/m and the high power incident waves is successfully reduced by 18 dB.Related reports are published on IEEE Antennas and Wireless Propagation Letters.Finally,attention is paid on the application of ESS protection.For sensitivity analy-sis,a finite ESS is modeled by using statistical method.The influence of randomness of circuit parameters and dry joints are analyzed by both simulation and experiment.By both simulation and measurement,graphene laminate with conductivity about 1.O×lO4 S/m is found to be effective for replacement of conductive metal in the design of ESS.