Energy Selective Surface Protection Mechanism And Analysis

Aiming at the protection of weapons and equipment against intense electromagneticwave, this paper presents a new method of energy selective surface (ESS) by energy low-pass mechanism. ESS overcame the shortage of existing measures in power capacity andprotection. As an innovation of intense electromagnetic protection, ESS, which not onlyisolate high altitude electromagnetic pulse but also allow the device to send and receivesignals normally, can be used to protect against both electromagnetic pulse bombs andhigh power microwave weapons. In this paper, ESS protection mechanism, functionaldesign, performance simulation, experimental tests and other key technologies have beendiscussed, rigid and flexible ESS fabricated, related experiments conducted.Based on the analysis of EMP(Electromagnetic Pulse) coupling channels, the threatlevel and the research status of intense electromagnetic protection in chapter one, ESShas been proposed to meet the needs of both high altitude electromagnetic protectionand devices sending or receiving signals successfully to compensate for the shortage ofexisting protection.In the second chapter, ESS and its protection mechanism were discussed. The im-proved surface impedance in impedance boundary has been defined, i.e. impedance sur-face proposed by the ratio of tangential electric field and surface current density, withwhich the ESS protection mechanism was described essentially by variable impedancesurface. In the end, the ESS realization was given by field-induced conductive materialand voltage conductive structure, and the ESS working mode determinate as active andpassive.ESS protection design is discussed in chapter three. Using voltage controlled con-ductive element array, an equivalent variable impedance surface is designed. To achievelow insertion loss characteristics of ESS, the PIN diode was selected for its conductiv-ity modulation characteristic, and its impedance characteristics studied. By adjusting thethickness and the carrier lifetime of the PIN diode or choosing active ESS, the adaptiveprotection threshold can be controlled. Considering the protection applications, the max-imum power capacity of ESS is estimated, the flexible conformal method also provided.Choosing High voltage PIN diode, the maximum protection field intensity of up to hun-dreds of kilovolts per meters showed that ESS can be effective protection of all existing reports electromagnetic pulse bombs and high power microwave weapons.In chapter four ESS performance analysis and synthesis were studied. A periodicstructure of infinite ESS model was established to achieve the FDTD-SPICE field cir-cuit co-simulation and to analysis the ESS time-frequency response. Protection index asinsertion loss, shielding efficiency, peak leakage, flat leakage and response time can beassessed. The ESS design process was give step by step to meet the requirements. Fornormal incidence of electromagnetic waves, if the ESS unit size can be ignored to theincident wavelength, an analytical solution can be obtained by field-circuit equivalentmethod.In the last chapter, ESS test methods were discussed. Rigid PCB ESS and flexibleFPC ESS samples fabricated, free space test program measurement improved. The exper-imental results show that the ESS sample has the protective performance of insertion lossless than 1dB, shielding efficiency more than 15dB in the frequency range below 3GHz.