High-power Electromagnetic Environments Research Articles

Analysis of the Interference Effects in CMOS Image Sensors Caused by Strong Electromagnetic Pulses

With the electromagnetic environment becoming increasingly complex, it is crucial to address the risk posed by electromagnetic pulse, which critically impairs the performance and reliability of electronic systems based on complementary metal oxide semiconductor (CMOS) image sensors. In this context, research on the failure types of CMOS image sensors in a high-power electromagnetic environment, caused by strong electromagnetic pulses and the rapid evaluation method of interference immunity, has garnered significant interest. This paper conducts electromagnetic pulse simulation experiments on CMOS image sensors to first study their failure types, such as image abnormalities and functional interruption, and then identify the corresponding failure criteria. Furthermore, this study builds on the small sample test evaluation method to investigate the interference threshold of functional interruptions in CMOS image sensors by calculating the failure probability at different field strengths. The obtained data were combined with the Weibull distribution function for fitting, the results of which found the interference threshold to be at 40.4 kV/m. The findings of this study provide a basis for evaluating the survivability of CMOS image sensors and their associated reinforcement technology in high-power electromagnetic environments.

Tightly coupled arrays with time-domain beam scan for the radiation of high-power ultrawideband electromagnetic pulses.

In this paper, a kind of tightly coupled array (TCA) with time-domain beam scan is developed for the radiation of high-power ultrawideband (UWB) electromagnetic pulses, and the peak-power pattern is proposed to characterize the directivity. First, the active voltage standing wave ratio (AVSWR) bandwidth of the TCA is optimized, which is the precondition for the beam scan. It indicates that the lower-cutoff frequency (LCF) is inversely proportional to the total length of the whole array; an increase in the distance between the array and the ground plane could remarkably reduce the LCF; and an increase in the element number can also decrease the LCF because of the increase in length, but more elements would make the center elements difficult to match in the low-frequency range, so there is a limitation on the number of elements for a certain LCF. Based on these results, a six-element linear array is designed. Then, the definition of the peak-power pattern is proposed to characterize the directivity of the UWB pulsed antenna. Finally, the optimized six-element array is developed, and the measured working band is 276 MHz-6.4GHz (AVSWR < 3). The effective potential gain is 1.76, and it improves by 51.7% with a reduction in the aperture area by 68.4% compared with the previous TCA, which means that the aperture efficiency is remarkably improved. The half-power beam width of the developed TCA with the scan angle of 0° is 45°. The time-domain beam scan could be performed with time-delay feeding lines, and the maximum scan angle is over ±30° in the E-plane. The developed TCA can be applied for the generation of high-power electromagnetic environments for the study of intentional electromagnetic interference.

Design and Testing of a Low-Tech DEW Generator for Determining Electromagnetic Immunity of Standard Electronic Circuits

This article describes the effect of high-power electromagnetic environments (HPEMs) on the operation of all basic elements of electrical power networks. Frequency bands are defined for the HPEM environments. Attention is focused particularly on directed energy weapons (DEWs) and intentional electromagnetic interference (IEMI). A classification of DEW and IEMI generators in terms of E-field level and target distance from the DEW or IEMI generator antenna aperture is also described. The main focus of this article is on the design and testing of a low-tech DEW generator used to determine the electromagnetic immunity of standard electronic circuits. In addition, verification of electromagnetic immunity for a simple electronic circuit without adequate protection against the E-field is also explained. The outcome of this article is the determination of the E-field limits for fault-free operation, for malfunctioning states of the tested circuits and for irreversible destruction of the circuits. The measured E-field was compared to basic microwave radiation theory and to simulation results in COMSOL Multiphysics software (COMSOL, Inc. 100 District Avenue Burlington, MA 01803 USA).

Implications of high-power electromagnetic (HPEM) environments on electronics

High-Power Electromagnetic (HPEM) environments can be considered to encompass lightning, Nuclear Electromagnetic Pulse (NEMP) and High-Power Radio Frequency (HPRF) phenomena including Directed Energy (DE) and Intentional Electromagnetic Interference (IEMI). HPEM environment definitions are now maturing and are now described in a variety of published standards. Methods to evaluate the effects on electronic systems and an understanding of effects mechanisms are perhaps less mature but this is a vibrant area of research. Due to a variety of factors described in this article protection and resilience of critical infrastructure from HPEM environments is becoming a pressing need.

Data Injection Attack Against Electronic Devices With Locally Weakened Immunity Using a Hardware Trojan

Intentional electromagnetic interference (IEMI) of information and communication devices is based on high-power electromagnetic environments far exceeding the device immunity to electromagnetic interference. IEMI dramatically alters the electromagnetic environment throughout the device by interfering with the electromagnetic waves inside the device and destroying low-tolerance integrated circuits (ICs) and other elements, thereby reducing the availability of the device. In contrast, in this study, by using a hardware Trojan (HT) that is quickly mountable by physically accessing the devices, to locally weaken the immunity of devices, and then irradiating electromagnetic waves of a specific frequency, only the attack targets are intentionally altered electromagnetically. Therefore, we propose a method that uses these electromagnetic changes to rewrite or generate data and commands handled within devices. Specifically, targeting serial communication systems used inside and outside the devices, the installation of an HT on the communication channel weakens local immunity. This shows that it is possible to generate an electrical signal representing arbitrary data on the communication channel by applying electromagnetic waves of sufficiently small output compared with the conventional IEMI and letting the IC process the data. In addition, we explore methods for countering such attacks.

Multinomial Regression Model for the Evaluation of Multilevel Effects Caused by High-Power Electromagnetic Environments

A lot of work has been done for the effects evaluation of electronic equipment due to high-power electromagnetic environments. The focus of the evaluation usually stays on whether the effects occur or not (“1” or “0”) during tests. However, in addition to such kind of either-or effects, multilevel effects happen in many practical cases as well. In this paper, we propose a kind of statistical approach for the evaluation of multilevel effects. By means of multinomial regression, the occurrence probabilities of each level of effects can be estimated simultaneously. Through maximum likelihood estimation (MLE), both the Softmax model and the mutually independent normal distribution assumption model are built and solved in a numerical way. We also talk about how the data affect the goodness of the regression. As a consequence, the Monte Carlo simulation gives a quasi-function relationship about model stability and estimation error. A case study on computer communication system has been conducted in the laboratory to assess the validity and applicability of the proposed models. The result is satisfactory for the three-level cases and gives all the probability prediction of the malfunction occurrences.

Wideband Shield Door With a Magnetic Absorber

It is necessary to secure a high shielding performance in a wide frequency range for a shield room to defend electrical equipment from high-power electromagnetic (HPEM) threat environments. We proposed a novel shield door with gaskets and magnetic absorbers. The magnetic losses of the magnetic absorbers realize the large shield effectiveness without impairing the door operability. The structures of magnetic absorbers are investigated through finite-difference time-domain (FDTD) analysis and experiments. We found that the multi-layered magnetic absorbers increase the shield effectiveness by 15 dB over a wide frequency range. Therefore, it is found that using the magnetic absorbers, high shielding performance can be achieved without impairing the door operability, which can provide an effective protection from the HPEM environments.

Distribution of cloud-to-ground lightning electromagnetic pulse fields under the ground

In order to find out the distribution of lightning electromagnetic pulse (LEMP) fields under the ground, the two-dimensional finite-difference time-domain method is used to calculate LEMP under the ground. The distributions of LEMP under the ground are calculated in the cases of different distances from the lightning channel, different ground conductivities, different ground permittivities and different depths. The attenuations of lightning fields in the ground are compared with those of other high-power electromagnetic environments. The calculated results show the following points: the LEMP dramatically attenuates as the distance increases; the attenuation of the electric component is significant when the ground conductivity is reasonably high; the change of ground permittivity mainly causes the change of vertical electric field component, which decreases as the ground permittivity increases; the attenuation of the high frequency electric component increases and that of the low frequency electric component invisibly changes as the depth increases.

Novel Parameter Estimation of Double Exponential Pulse (EMP, UWB) by Statistical Means

High-power electromagnetic environments, such as the high-altitude electromagnetic pulse (HEMP) and the ultrawide-band (UWB) pulses, pose dangerous threats to electronic systems. Such pulse shapes are often described physically by the characteristic parameters: the rise time tr, pulse width tfwhm and maximum electric field strength Emax, and mathematically by the double exponential function with characteristic parameters alpha, beta ,kappa . and E0. In practice, it is very necessary to transform the two groups of parameters into each other. In this paper, a novel relationship between the two groups of parameters is established by statistical means. This method utilizes only four assistant variables to realize the transform, and the overall estimation error is less than 2.0%.