Electromagnetic Environmental Effects Research Articles

Improved Hybrid Leapfrog ADI-FDTD Method for Simulating Near-Field Coupling Effects Among Multiple Thin Wire Monopole Antennas on a Complex Platform

A hybrid one-step leapfrog alternating-direction-implicit finite-difference time-domain (ADI-FDTD) method integrated with a thin wire algorithm is developed for simulating the near-field mutual coupling effects among multiple wire antennas on an electrically large warship platform, where induced surface current and electric field distributions are also captured. Its stability analysis, based on von Neumann method, is performed in a semi-analytical way and verified numerically. In order to demonstrate its accuracy and efficiency, the near-field mutual coupling effect between two thin wire antennas is at first investigated. Then, it is applied to accurately characterize complex electromagnetic environment effects on a warship with multiple thin wire antennas, and the results are compared with those obtained by the other commercial simulators.

Electromagnetic and Other Environmental Effects Following Near-Death Experiences: A Primer

Article describing the results of informal and formal research regarding electromagnetic (EM) effects of near-death experiences (NDEs); it reviews cases in which a person acts on his environment and those in which a person reacts to the environment. The paper also proposes more precise terminology regarding EM phenomena based on the research and literature review.

Electromagnetic and other environmental effects following near-death experiences: A primer.

Article describing the results of informal and formal research regarding electromagnetic (EM) effects of near-death experiences (NDEs); it reviews cases in which a person acts on his environment and those in which a person reacts to the environment. The paper also proposes more precise terminology regarding EM phenomena based on the research and literature review.

Analysis of statistical nature of induced voltages at key points in computer box cavity in different frequency ranges

The statistic characteristic of induced voltages at key points in computer box cavity is researched by means of experiments and the random coupling model （RCM）. It is shown that the experiment results generally agree with the theoretical results in trend. The applicability of RCM in analysis and predication of system-level electromagnetic environment effects is validated. A new method based on statistical electromagnetism should be exploited for the analyses of electromagnetic effects for large scale nonparallel surface electron device-box cavity systems.

Analysis of systemic electromagnetic environment effects based on Random Coupling Model

By experiment and Random Coupling Model（RCM）, the statistic characteristics of induced voltages at key points in computer box cavity are studied. The calculating method and application diagram of RCM is given. Scattering coefficients, the statistic characteristics of normalized scattering coefficient and normalized impedance coefficient are researched by experiment and theory. It is shown that the experiment results generally agree with the theoretical results in trend. Application of RCM is preliminarily discussed. Applicability of analysis and forecast on systemic electromagnetic environment effects based on RCM is validated. Especially, the RCM is applicable to investigation on electromagnetic compatibility, effects and assessment for the large scale nonparallel surface electronic systems.

나로호의 EMC 통제를 위한 규격설정 및 검증

소형 위성 발사체 나로호의 전자파 적합성 성능은 탑재 위성과 우주센터에 설치되는 지상 장비, 그리고 다른 무선통신망 사이에서 정상적인 동작을 보장하도록 확보되고 검증되어야 한다. 전자파 적합성 성능을 검증하기 위해서는 서브 시스템과 시스템에 대한 적절한 시험 규격과 방법, 그리고 절차가 발사체의 운용 특성과 전자기 환경을 고려하여 수립되어야 한다. 그리고 프로그램 종료단계까지 결정된 규격에 따라 지속적으로 전자파 적합성 특성을 유지 관리하는 것이 요구된다. 본 논문에서는 나로호의 발사체 개발 전 주기 동안 수행된 순차적인 관리 업무를 기술하고, 나로호와 각 서브 시스템의 각 모델에 대한 단계별 시험계획뿐만 아니라, 시험 방법, 규격, 검증시험 결과 등이 제시된다. 또한, 멀티팩션 분석에 대한 결과를 기술한다. Electromagnetic compatibility(EMC) performance of the first Korea space launch vehicle(KSLV-I) should be ensured and verified in order to guarantee the normal operation among the spacecraft, ground facilities which are installed in the space center, and other wireless communication networks. For the purpose of the EMC performance verification, pertinent EMC test specifications, methods, and procedures for both the subsystems and the system should be established in consideration of operational properties and electromagnetic environmental effects. And it is required to maintain and control the EMC properties consistently in accordance with the determined specifications up to the program closing phase. In this paper, sequential management work conducted during the overall development process of the KSLV-I is explained, and not only the phased EMC test plan for each model of the KSLV-I and its subsystem but also test method, specification, and results of the verification tests are presented. And also, multipaction analysis results are presented.

基于随机耦合模型的系统级电磁环境效应分析

基于随机耦合模型的系统级电磁环境效应分析

Impact of lightning and high-intensity radiated fields on cables in aircraft

This article shows how electromagnetic simulation tools can be used early in the design stage to predict the impacts of lightning and high-intensity radiated fields on cable harnesses in aircraft. Furthermore, it shows how with such tools appropriate cable shielding can be devised that ensures the aircraft will pass the Electromagnetic Environmental Effects testing without adding unnecessary weight.

Novel injection methods for substitution of irradiation under different coupling routes of electromagnetic interference

At present, the maximum electromagnetic radiated field strength which can be simulated is not able to satisfy the requirements of electromagnetic environment effects tests on electronic systems. To broaden the effective frequency range of the current injection technique, new current injection methods were put forward for substitution of the radiation. A wide-band current injection device was designed based on the symmetric directional coupler principle. With a typical antenna receiving system under test, the validity of the methods were analyzed by theory and verified by experiments when the Equipment Under Test (EUT) had different coupling routes of electromagnetic interference (EMI). The results indicate that: firstly, the relationship between radiated fields and injected voltage is linear, even if the responses of the system are non-linear; secondly, the method is valid even if the test frequency is up to gigahertz; thirdly, the novel methods of current injection are able to substitute for irradiation effectively when the antenna and the interconnected cable are the main coupling routes of EMI respectively.

Research on the test method of using injection as an equivalent substitute for electromagnetic radiation

This paper presents a method to carry out high intensity radiated field (HIRF) effect experiments by using injection as an equivalent substitute for electromagnetic radiation. In allusion to typical interconnected system, the equal response voltage on the equipment cable port is regarded as an equivalent basis of injection and radiation methods. The equivalent relation formula between injected voltage and radiated field is derived theoretically. The conditions needed for extrapolating injected voltage in HIRF are confirmed, and the extrapolation method is proposed. On the basis of the above research, the electromagnetic environment effect test new method combined injection with radiation for interconnected system is summarized. The typical nonlinear interconnected system is selected as equipment under test, and the single frequency continuous wave radiation and injection effect experiments are carried out separately. The test results indicate that the relation between radiated field and injected voltage is linear, and the equivalent injected voltage used to substitute HIRF can be obtained by linear extrapolation.

ELINT 포드를 장착한 전투기의 전자기 환경 영향(E3) 시험평가에 관한 연구

This paper describes the verification test on Electromagnetic Environmental Effects(E3), which conducted on ground as a final step to confirm the normal operation of ELINT pod and Safety-of-Flight of KF-16C/D mounted with ELINT pod prior to the initial flight. Based on MIL-STD-464A, indispensable 7 requirements among 14 detailed requirements total were carried out in the test. Considering the Safety-of-Flight(SOF), we invest a great deal of time and effort on Hazards of Electromagnetic Radiation to Ordnance(HERO) and Intra-system EMC test. E3 test and evaluation were performed on 62 equipments of KF-16C/D, respectively. As a result, we verify that KF-16C/D mounted with ELINT pod(hereafter "system") are electromagnetically compatible among all subsystems and equipment within the system and with environments caused by electromagnetic effects external to the system.

Investigation of the Risk of Electromagnetic Security on Computer Systems

Electromagnetic environmental effects (E3) and compromising emanations (CE) are two centrally important aspects of computer closely related to electromagnetic security. This paper investigates the electromagnetic compatibility (EMC) for functional safety and emission security on computer systems. Initially, the EMC security issues for the electromagnetic emission of computer systems as well as the susceptibility of tremendously increased critical circuits are presented. Then, impact of electromagnetic security in ubiquitous applications based on computer technology is discussed, which encompasses the damage of E3 and risk potential, CE security limits and experiment example of TEMPEST. Finally, the protection means of computer electromagnetic security are provided. The paper states the need for the guidelines on controlling EMC and the process of CE to achieve electromagnetic security of computer systems.

Electric fields induced by a modified double exponential current waveform

Abstract This paper presents a novel approach for developing a closed form solution for a lightning generated electric field which uses a modified double exponential base-current waveform. In the literature, several models have employed the square pulse waveform to derive the corresponding electromagnetic fields. However, given the Department of Defense (DoD) has incorporated the double exponential current waveform as part of their “Electromagnetic Environmental Effects Requirements For Systems”, it is noteworthy to develop a solution for the electric field which utilizes this waveform. In order to facilitate the integration required for deriving the field, Taylor series expansion will be used for all variable dependent exponential terms within the current waveform. This methodology greatly simplifies the integration required to solve for the electric field in an approximated closed form. However, by utilizing Taylor series to approximate the variable dependent exponentials, the electric field’s accuracy becomes a function of the number of terms used. Consequently, a correction factor will need to be added in order to help reshape the electric field which resulted from the modified base-current waveform.

Research on VR-Based Experiment Space for Complex Electromagnetic Environment

Virtual Reality technology is a hot research field in simulation of complex electromagnetic and its practical environment in the condition of information and high technology war. The paper discussed the main framework of spatial electromagnetic environment computing and simulating, presented realizing method and key arithmetic designing based on Virtual Reality Modeling Language. The work is evidently valuable for quantitative examinations, evaluation, and analysis of complex electromagnetic environment function, diversification, and effect on human beings, electronic units.

The Magnetic Field Induced by a Lightning Strike's Indirect Effect Double Exponential Current Waveform

Problem statement: Develop a new formula which describes the magnetic field induced by a lightning strike's indirect effect double exponen tial current waveform. Approach: A novel approach for developing a closed-form solution for the magne tic field from the indirect effect double exponential current waveform will be presented. In the literature, models typically employ the pulse waveform to derive the corresponding electromagnetic fields. However, given the Department of Defense (DoD) has incorporated the double exponential current waveform as part of their Electromagnetic Environmental Effects Requirements For Systems, we felt it important to develop a solution for the magnetic field which utilized this waveform. In order to facilitate the integration required for deriving the field, Taylor series expa nsion was used for all variable dependent exponenti al terms. In many publications, the dipole and monopol e techniques have been used when solving for the magnetic field. However, for this study the dipole technique was deemed the preferred method for evaluating the field. A derivation of the magnetic field will be presented along with a graphical illustration of the field's distribution over time. Results: The equation presented utilized Taylor series to augment the integration required to solve for th e magnetic field. Conclusion: A new method for deriving the magnetic field induced by a lightning strike's indirect effect double exponential has bee n presented. By approximating the variable dependent exponential terms, we were able to minimize the complexity of the mathematics required to solve for the magnetic field in closed-form.

Electromagnetic Environmental Effects Testing of Medical Devices Including Those Used for the Treatment of Diabetes

Electromagnetic emissions from technologies that surround us can produce interference with implanted and externally worn medical devices. Electromagnetic environmental effects (E3) testing of medical devices at the Georgia Tech Research Institute (GTRI) began almost four decades ago and continues to incorporate new devices and new sources of electromagnetic emissions as they are developed and become available. The GTRI Medical Device Test Center provides real-world exposure fields to identify interactions and help manufacturers prevent disruptions from the environments in which their devices must function. Typically, the medical device is mounted in or on a torso simulator containing a saline solution that simulates the electrical characteristics of the body. The torso simulator and the device under test are then moved through the fields generated by production security and logistical system technologies using a computer-controlled positioning system. These tests are conducted with different orientations of the medical device to the electromagnetic source, simulating the way in which device wearers interact with these systems in representative situations. Particular E3 test results measured on specific devices in the GTRI Medical Device Test Center are proprietary; however, the results of tests to date with current medical devices used for the treatment of diabetes have been encouraging. These devices have included implantable and externally worn insulin infusion pumps and continuous glucose monitoring systems from different manufacturers. Since E3 tests of diabetes treatment devices to date in the test center have centered on devices from only a few of the many current manufacturers, further testing is warranted. In addition, increased functionality, which is being added to existing devices, will create new possibilities for interference in the future.

Effect of electromagnetic environment on the dielectric resonance in the ferroelectric-ferromagnetic composite

The influence of electromagnetic environment on resonance character of dielectrics was studied in the ferroelectric-ferromagnetic composite. The magnetic phase induces inhomogeneous electromagnetic environment, which will baffle the motion of charged particles in neighboring ferroelectric grains. The influence is not strong enough to change the dielectric properties of composite except for its dielectric resonance character. With the rise of permeability or proportion of magnetic phase, the dielectric resonance peak turns wider and smoother. The dielectric response tends to transit from resonance to relaxation. The electromagnetic interaction between components will prevent the resonance character for the equilibrium of the system.

NETEX UWB test results

The goal of the Defense Advanced Research Projects Agency's (DARPA) Networking in Extreme Environments (NETEX) program is to create a wireless networking technology for the military user that enables robust connectivity in harsh environments and support its integration into new and emerging sensor and communication systems. Phase 1, resulted in a thorough understanding of the effects of ultra wide band (UWB) system operation on existing military spectrum users based on modeling, simulation, and measurements. In order to accomplish this task, the DARPA Advanced Technology Office (ATO) procured a set of UWB emitters and broadband antennas to use as interference sources and contracted with the Naval Air Warfare Center Aircraft Division (NAWC AD) Electromagnetic Environmental Effects (E/sup 3/) Division to provide candidate victim systems from the existing (legacy) US naval aircraft and shipboard inventory for testing. Testing was conducted on seventeen legacy systems during October 2002 through March 2003. The purpose of this paper is to provide a brief overview of the results of these tests. This paper will provide a brief discussion of the UWB emissions as described by the US Federal Communications Commission (FCC) and describe the generic UWB emitter used for these tests. It will then provide a discussion of the results as they apply to the purpose of the NETEX program.

Disordered junction arrays used for Coulomb blockade thermometry

A possible application of nanometer-sized junction arrays is to Coulomb blockade thermometry (CBT), although only highly disordered arrays can be fabricated at present. In this paper, the characteristics of CBT device with disordered arrays will be studied. Similar to what is observed for uniform arrays, there is a dip at zero bias voltage in the differential conductance of disordered arrays. However, the half-width of the dip for one-dimensional disordered arrays is largely dispersed. This study suggests that better devices can be developed by connecting a number of one-dimensional arrays in parallel to form an array group. The dispersion of half-width is quite small with values of close to a constant. Further, the effects of electromagnetic environment and low temperature on the half-width are investigated. Results are agreed with those observed experimentally, that for the effect of the environment is negligible for large arrays. The half-width of a disordered array may be bigger or smaller than the ideal value, depending on the extend of disorder.

Radiation correction to astrophysical fusion reactions and the electron screening problem

We discuss the effect of electromagnetic environment on laboratory measurements of the nuclear fusion reactions of astrophysical interest. The radiation field is eliminated using the path integral formalism in order to obtain the influence functional, which we evaluate in the semi-classical approximation. We show that enhancement of the tunneling probability due to the radiation correction is extremely small and does not resolve the longstanding problem that the observed electron screening effect is significantly larger than theoretical predictions.