The study of electromagnetic sensitivity of electronic modules is crucial for the selection of a component-level pulse current injection (PCI) waveform, which will determine whether a component-level PCI test is equivalent to a system-level pulse illumination test of the system to which the electronic module belongs. For electromagnetic sensitivity analysis, the equivalence between the injection waveform and a typical high-altitude electromagnetic pulse (HEMP) conducted disturbance waveform in a component-level PCI test is studied. Based on an RF low noise amplifier (LNA) test board, component-level PCI tests were performed using 20 ns/500 ns double exponential wave and square-wave pulse with multiple pulse-widths. The damage threshold was analyzed and determined by using vector norm and its internal damage was observed and validated by optical microscopic analysis. The conclusions are demonstrated as follows: first, during square-wave PCI tests of RF LNA, the electromagnetic sensitive parameter action is divided into three regions by pulse-width range, called $\infty$-norm, 2-norm and competitive failure-dominating regions; second, the electromagnetic damage effect of the RF LNA is mainly caused by the burning of its two cascaded transistors, forming a pulse energy transmission channel with short-circuit impedance from the input port to the ground; third, the 100 ns-width square waveform can be determined as the equivalent injection waveform of a HEMP conducted waveform, and the pulse peak value of injected current is determined as the electromagnetic sensitive parameter for square-wave PCI tests of the RF LNA. The conclusions verified the feasibility of establishing the equivalence between different pulse waveforms according to the electromagnetic sensitivity analysis based on the vector norm theory and effect mechanism analysis.

The existing literatures, concentrating on the statistical analysis of transient response of antennas, radiated by high-altitude electromagnetic pulse, always choose an area-based method to calculate the statistics from the perspective of explosion. However, it may be more suitable to analyze from the view of the affected facility position. In this paper, we demonstrate a statistical analysis comparison of multiple norms of the transient response from both viewpoints. Distinguished from the burst view, the location of the affected facility is set as the observer location, and the formulas of uncertain factors, involved in the HEMP coupling calculation of monopole antenna, are derived. An efficient statistical method, based on Polynomial Chaos and Moment of Method, is applied to compute the statistical results of monopole antenna in a finite conductive plane. The statistical comparison reveals several primarily interesting conclusions in the end, which will be beneficial for system-level HEMP vulnerability assessment.

A stochastic finite-difference time-domain approach for analyzing geometrical and media uncertainty is described. The proposed method can convert the geometry uncertainties into media uncertainties based on the conditional probability. It can solve 1-D, 2-D, and 3-D problems. In order to improve the accuracy of the method, the improved correlation coefficients related to space division are proposed. The proposed method and improved correlation coefficients are validated with simulations of both 1-D and 3-D stochastic scattering objects. The simulation results agree well with the results of the Monte Carlo (MC) method, while the computation time of this method is only about 2% of the time consumption of the MC method.

High power electromagnetics (HPEMs) pose a potential threatening risk to the wireless communication system, especially according to the main coupling path of the RF front-end channel. SPICE modeling of the responses coupled on the RF channel is crucial for the EM risk assessment, which helps us learn more about how the pulse conducts on the RF channel. A simplified linear RF channel with pyramid horn antenna is taken as an example by the selection of the key electronic modules of the actual wireless system. This paper proposes a system-level SPICE circuit model for the simplified RF channel according to the hybrid methods of the antenna electromagnetic simulation and SPICE modeling of the RF circuit. The equivalent circuits of the horn antenna illuminated by HPEMs are established with the Vector Fitting method based on Thevenin and Norton theorems. The short current response as the excitation files for the SPICE models are obtained by the commercial electromagnetic simulation of the horn antenna illuminated by Multiple HPEM environments. Equivalent circuits of a micro-strip bandpass filter are also derived with $\pi$ type circuit structure based on the measured admittance data. Then we analyze the HPEM risk faced by the RF channel by considering multiple HPEM environments. The norm theory is utilized to analyze the waveform characteristics from electric fields of HPEMs to the responses of the RF channel. The ratios of the responses versus electric field for each norm are computed and the EM risk degree is ranked based on those results. The results demonstrate that high power microwave is the highest threatening risk for the linear RF channel compared to the other two HPEMs such as ultra-wide band, high altitude electromagnetic pulse. Finally, the flowchart of EM risk assessment is presented based on a previous analysis, which will benefit the EMC design in engineering.

The uncertainty of the simulation results is large due to the modeling error and numerical dispersion, when using the existing numerical simulation method to obtain the time-domain waveform of enclosure with apertures. In this paper, an approximate solution of the shielding effectiveness curve of any position in an enclosure with apertures was obtained by the analytic algorithm. The time-domain waveform of the enclosure with apertures was further analyzed by using the minimum phase method, and the validity of the modified method was verified by comparison with the CST simulation results. Compared with the current method of artificial intelligence for predicting shielding effectiveness, the method has a solid physical foundation and is fast and convenient. It has reference significance for system protection design, test and so on.