Analysis of the Double Metal Cavities′ Aperture Coupling by HEMP Plane Wave

High-altitude electromagnetic pulse(HEMP) poses a serious threat on the electronic/electrical equipment,which is an important research field of electromagnetic compatibility(EMC) and the security of electronic/electrical equipment.Computing model is built by the total-field/scattered-field of the finite difference time domain method(FDTD),and 1-D plane wave method is imported in the connecting surface.Then,the apertures′ response of double metal cavities under the HEMP plane wave is simulated and analysed using FDTD.The simulation results show that all samples are showing clear oscillatory shape,and the peak electric field in aperture center of external metal cavity is larger than that of the center point of internal metal cavity.With the same aperture′s size,the internal coupling electric fields of the square aperture,rectangular aperture are smaller than that of circular aperture.The distance of the apertures between internal cavity and external cavity will also affect the coupling results,and the greater distance makes more attenuation of the internal coupling electric field.The conclusions are able to provide guidance for the protection design of double metal cavities.