This paper presents simulation program with integrated circuit emphasis (SPICE) models for the analyses of the radiated and conducted susceptibilities of shielded coaxial cables. Derived from the transmission-line equations of shielded cables, these models can be directly used for the time-domain and frequency-domain analyses, and connected to nonlinear and time-varying loads with the models already available in SPICE. In the proposed models, the usual discretization of shielded cables is not needed, and both the transfer impedance and admittance have been taken into account. Results obtained with these new models are in a good agreement with those obtained by using other approaches.

—This paper studies the loss effect of the line and the validity of a SPICE model for lossless transmission lines excited by an incident plane wave by using a simple structure —a single line over an infinite perfectly conducting ground excited by an incident electromagnetic field. The frequency domain,current responses calculated by the Baum-Liu-Tesche (BLT) equation with the loss ignored are compared with those through the BLT equation with loss considered to study the loss effect of transmission lines. The loss effect study shows that the SPICE model for lossless transmission line can be used for nuclear electromagnetic pulse, ultra wideband, and the low-frequency range of high power microwave interaction with most systems. But for a sine or cosine wave of which the frequency equals the pole frequency of the line, the SPICE model may lead to significant error.

Stochastic electromagnetic fields coupling to printed circuit board (PCB) traces are important to the understanding of electromagnetic compatibility at high frequencies when the circuits or systems are electrically large. In this article, it is studied both numerically and analytically, and the factors affecting the absorbed power are investigated. We present new methods to determine the level of coupling on PCB traces or other transmission lines on a dielectric substrate. A Monte Carlo method is applied to generate random uniform fields, and the quasi-TEM transmission line model is employed to compute the response of the trace for each plane wave numerically. In the analytical method, the closed-form expressions of the zero-order and the first-order approximations are established for the PCB trace. Based on the first-order approximation method and the numerical results, a computationally efficient empirical method is developed to estimate the power received. The absorbed power increases with frequency in the electrically short case after which multiple resonances can be seen. The absorbed power in the matched case is neither the largest nor the smallest among all the cases. It increases with the square of the substrate height but decreases with the permittivity of the substrate.

Some electromagnetic pulses, such as the high-altitude electromagnetic pulse (HEMP), can couple with power lines in the range of thousands of kilometers. Conventional numerical methods cannot efficiently predict the voltage induced by the early-time (E1) HEMP on the power lines in a large area. This paper presents an efficient model based on an artificial neural network (ANN) which can predict the coupled voltage induced by the E1 HEMP on distribution power lines quickly. Based on Agrawal's model of the electromagnetic field coupling with transmission lines, the important parameters which affect the coupled voltages of distribution power lines are analyzed firstly. The Baum-Liu-Tesche equation and inverse Fourier transform is applied to compute the voltage magnitude when the elevation angle, azimuth angle, and the polarization angle of the E1 HEMP change and more than twenty thousand numerical results are obtained. Then an ANN is developed and trained by the numerical results. Once the ANN is trained, the prediction time is on the order of milliseconds. The results show that the proposed model based on the ANN can provide accurate prediction results for the E1 HEMP coupling with power lines at different observation points.

A hybrid method of full-wave-transmission-line approach is established to calculate the transient response of the shielded cable vertically laid to the ground when illuminated by a high-altitude electromagnetic pulse. In the approach, the induced current on the external sheath is evaluated by Holland's thin-wire finite-difference time-domain method, while the response of the inner conductor is solved by the classic transmission-line method at the same time. Using the proposed approach, the termination currents of both conductors are computed and analyzed to conclude the general rules and waveform characteristics in the specified situation. Evaluated results show that the hybrid method gets good accuracy and efficiency, and the variations of the currents with several parameters are studied.

The study of high-altitude electromagnetic pulse (HEMP) coupling with overhead power lines is crucial for assessing potential damage to power systems. This paper presents a method that utilizes two deep neural networks in conjunction with theoretical analysis to rapidly compute HEMP coupling with overhead lines in the range of thousands of kilometers. This approach accounts for the varying characteristics of HEMP at different observation points and takes approximately 19.64 seconds on a notebook computer to compute the spatial distribution of the coupled voltage, which is about 2.88 million times faster than numerical methods. This efficiency reduces computational demands and demonstrates significant potential for applications in conventional nuclear physics. The results indicate that the spatial distribution of the peak coupled voltage resembles a "double egg yolk”, different from the smiley face of the HEMP. The results also show that the relationships between coupled voltage and blast parameters differ significantly from those observed in HEMP scenarios.