Intentional Electromagnetic Pulse Research Articles

Coupling Analysis of Shielded and Unshielded Star Quad Cables Excited by an Intentional Electromagnetic Pulse

Coupling analysis of shielded and unshielded star quad cables excited by an intentional electromagnetic pulse (IEMP) is investigated using the transmission line theory-based perturbation technique. A detailed modal analysis is presented to obtain the modal per-unit-length parameters of the modal signals in such shielded/unshielded star quad cables. Due to their geometrical balanced structures, with opposite wires used for +leg and −leg to transfer the differential-mode (DM) signal, the external coupling is dramatically suppressed. Moreover, stochastic analyses based on the Monte Carlo simulation are also performed to study the sensitivity of the induced common-mode (CM) and DM currents, due to the deformation effects of the twisting structure of the cable. It is found that the induced CM and DM currents are slightly affected by the twisting deformation of the cable because the interference cancelations do not mainly depend on the twisting loops of the cable. In particular, time domain analysis is performed to study the field-to-wire coupling of the star quad cables exposed to an IEMP, where the worst-case waveform signals in the presence of an IEMP attack are captured and analyzed.

Study on SAR Distribution of Human Body on the Vehicle Platform Using a Modified FDTD Method

This paper is devoted to characterizing the specific absorption rate (SAR) distribution of a human body model in a vehicle-based shelter in the presence of high-power intentional electromagnetic pulse (IEMP) radiation using a modified finite-difference time-domain (FDTD) method. The proposed method combines the FDTD(2, 4) method along with dielectric conformal techniques, where the updating equations of FDTD(2, 4) method are modified by introducing an effective dielectric constant and a new conductivity derived by area average of different dielectric regions including coating layer in nine spatial discrete cells. Numerical results show that our method even with coarse meshes has good agreements and efficiency comparing with the traditional FDTD method and CST simulation tool. Furthermore, the proposed method is applied to predict the SAR distribution of human body in a vehicle-based metallic shelter, where the peak SAR and average SAR are captured and compared in the presence of an IEMP with different polarizations and incident angles.

A NOVEL DIELECTRIC CONFORMAL FDTD METHOD FOR COMPUTING SAR DISTRIBUTION OF THE HUMAN BODY IN A METALLIC CABIN ILLUMINATED BY AN INTENTIONAL ELECTROMAGNETIC PULSE (IEMP)

One novel dielectric conformal flnite-difierence time- domain (FDTD) method is used for computing speciflc absorption rate (SAR) distribution over the human body model in one metallic cabin with some windows on its wall. It is based on the concept of area average, which is difierent from other traditional conformal FDTD schemes. Our developed algorithm is verifled by calculating both point and average SARs of dielectric sphere and human head models illuminated by an intentional electromagnetic pulse (IEMP), respectively, and CST Microwave Studio (MWS) also used for validating its accuracy. Numerical calculations are further performed to show the average SAR distribution over the human body model for difierent IEMP incidences, where the cabin door is opened or closed. The efiects of E-fleld amplitude, direction and polarization of the incident IEMP on the SAR distributions are characterized in detail. This study will be useful for further electromagnetic protection for some persons working in high power exposure environment.