Electromagnetic Pulse Coupling And Damage Effect, Shielded Chassis Hole Seam

Electromagnetic pulse(EMP) can be produced by nuclear explosions,lightening, high-power microwave bomb, electromagnetic pulse bombs and other methods, which can damage electronic equipment for radar, communications systems and weapons systems. For example, electromagnetic pulse can damage the crystal diodes, transistors, integrated circuits, resistors, capacitors, filters, relays and other components used in electronic equipments.Electromagnetic pulse(EMP) acts on shielding box primarily through conduction coupling and radiation coupling. Coupling path mainly includes "front-door coupling" and "back-door coupling. "The "front-door coupling" refers to that electromagnetic pulse interferes with or damages the front-end electronic equipment through such as the antennas and transmission lines ,which are used on the systems; The "back-door coupling" refers to that electromagnetic pulse interferes with or damages integrated circuits and microelectronic devices used in electronic equipment through apertures and slots used in the systems.The coupling energy through the "front-door coupling" may be separated by system's protection devices,which will not interfere with or damage systems.The various functions of the apertures are essential to the shielding box. Electromagnetic pulse couples into the shielding box through the "back-door coupling", which inevitably interferes with or damages the electronic components used in the shielding box. The "back-door coupling" is one of the important ways to couple into the shielding box.The main studies and goals in this paper are simulation studies of EMP aperture coupling and damage effects.The main studies and goals in this paper are as follows. In frequency domain,we use the software HFSS,which is based on finite element method,to simulate the resonant frequency of shielding boxes with different dimensions, influences of slots on shield effectiveness, etc. In time domain,we use the software XFDTD,which is based on Finite-Different Time-Domain,to simulate influences of risetime and pulse width on coupling, enhancement effect, influences of PCB on aperture coupling, damage effect of EMP to the shielding box, influences of risetime and incident field intensity on power density in the mainboard area , etc.