Electromagnetic Susceptibility Tests Research Articles

Adaptive EMS Test Design Method on UAV Data Link Based on Bayesian Optimization

The complex electromagnetic environment makes the electromagnetic susceptibility (EMS) test challenging for the unmanned aerial vehicle (UAV) data link. The EMS test can be regarded as an optimization problem to obtain the maximum signal-to-interference ratio that makes the data link losing lock. In this article, we proposed an adaptive EMS test design method based on Bayesian optimization to expand the ability of the EMS test toward the UAV data link. The sensitive electromagnetic interference parameters can be automatically searched according to the adaptive test design method. The Gaussian process is used as the surrogate model for the EMS threshold. Besides, acquisition functions are discussed, including the probability of improvement, expected improvement, and upper confidence bound to balance the exploration and exploitation. Then, two test examples are applied to verify the adaptive test design method. Compared with the traditional EMS test methods, the proposed method introducing Bayesian optimization into the EMS test design can significantly improve the test efficiency and achieve an excellent human-in-the-loop effect.

Broadband Pulse Injection Probe With Improved Injection Efficiency for Conducted Electromagnetic Susceptibility Test

A broadband pulse injection probe with improved injection efficiency for conducted electromagnetic susceptibility (EMS) is proposed in this article. Improved injection efficiency is effective and crucial for conducted EMS testing of electronic devices. The effect of parameters, such as coil material and wire diameter, the number of coil turns, and the distance between the coil and the shielding shell on probe injection efficiency, is investigated in this article. By using low-impedance coils, symmetrical winding methods, and size-matched shielded shell, the broadband pulse injection probe with improved injection efficiency is obtained. The proposed broadband pulse injection probe was calibrated, and an injection efficiency comparison test was performed, proving that the proposed probe has improved injection efficiency. Meanwhile, the proposed injection probe performs well in EMS testing in the 9-kHz–400-MHz frequency range. These results will be of great significance for the effective acquisition of EMS test data and the optimal design of electromagnetic compatibility (EMC) of integrated circuits (ICs).

Generation of Mesoband Signals With Optoelectronic Technique and a Combiner for Intentional Electromagnetic Interference Conducted Tests

In this article, a source for generating conducted intentional electromagnetic interference with a mesoband spectrum is presented in order to perform electromagnetic susceptibility tests on electronic equipment. This high-voltage source is based on different optoelectronic generators, which integrate photoconductive semiconductor switches (PCSSs) operating in a linear switching mode and triggered by a laser pulse. These optoelectronic devices generate a damped sinusoidal signal with a center frequency between 20 and 200 MHz, a Q factor between 11 and 12.4, and a maximum peak-to-peak magnitude of 3.12 kV for a bias voltage of 4 kV. An optoelectronic generator model was designed using Advance Design System (ADS) software, and experimental tests were performed with a measurement bench to compare simulated and measured results. A study on a voltage increase of these generators has been performed and has established the experimental limits of generation in planar technology with low-cost PCSS available on the shelf. The highest peak-to-peak magnitude value obtained is 6.10 kV, it is possible, thanks to the design and manufacture of a power combiner, with ADS and CST Suite Studio software tools, to set up a multiway combination.

Research on several test issues of electromagnetic radiation susceptibility for electronic equipment

According to the practical problem that some electronic equipments still exist electromagnetic incompatibility phenomenon in training and fighting stage after passing the normal electromagnetic compatibility test required by National Military Standard of China, on the basis of systematically analyzing the technical requirements and test methods in the current military standard, considering the technology accumulation of our research team on the electronic information equipment electromagnetic environment effects in recent years, the influence the several conditions on the electronic information equipment electromagnetic radiation susceptibility test results were discussed. These conditions contain not searching the sensitive receiving direction of the equipment under test(EUT), lacking of electromagnetic radiation susceptibility test in in-band frequency, multi-source radiation causing remarkable reduction of the susceptibility threshold of the EUT and so on. On the basis of the discussion, the measures and suggestions which can solve the above related problems were given. The development tendency of the high intensity electromagnetic radiation effect test technology and the complex electromagnetic environment adaptability evaluation technology for electronic equipment were discussed.

Prediction of Electromagnetic Compatibility for Dynamic Datalink of UAV

The operation signal of an unmanned aerial vehicle's (UAV's) datalink will change with the flight radius and attitude, which leads to a dynamic variation of the electromagnetic susceptibility (EMS) of the datalink against the external electromagnetic interference. In order to predict the electromagnetic compatibility (EMC) for the dynamic datalink of a UAV, the operation signal of the UAV's datalink and the received interference by the UAV need to be quantified and the EMS is also necessary to be tested. In this paper, a new model of the UAV's datalink in different flight states is presented. The relationship among the airborne operation signal, the interference and the flight parameters is presented and compared in three typical flight states, i.e., the fixed angle state, dive state, and hover state. To increase the repeatability and accuracy of the test and avoid risks in a flight test, a novel EMS test method using a static test instead of a dynamic flight test is proposed. On the basis of the operation state and its corresponding EMS threshold, the EMC prediction is performed to determine the moment when the datalink will be interrupted. The new method can be used to improve the security of UAV in the severe electromagnetic environment.

Design of Optoelectronic Generators for Mesoband Conducted Effects Testing

In this article, a damped sinusoids high-voltage source based on the optoelectronic waveform generators principle is presented to perform electromagnetic susceptibility testing. Photoconductive semiconductor switches (PCSS), operating in linear switching mode and triggered via a laser pulse, have been used. The developed conducted source generates damped sinusoids with a center frequency between 30 and 600 MHz, a maximum peak-to-peak amplitude of approximately 3 kV for a bias voltage of 4 kV, a Q factor between 8 and 11, and a transient shape closest to a reference damped sinusoid. The dimensions of the source go from 220 mm × 80 mm to 220 mm × 510 mm. A PCSS characterization has been set up to determine the necessary parameters for the establishment of a damped sinusoids optoelectronic generator model on Keysight Advanced Design System software. Experimental tests have been realized using a measurement bench to compare the obtained and simulated signals.

전기자동차 충전구 위치에 따른 전자파 방사특성에 관한 연구

According to revolutionary developments in automobile technologies, eco-friendly advanced vehicles (hybrid vehicle, hydrogen fuel-cell vehicle, electric vehicle, etc.) are rapidly increasing. The electromagnetic compatibility is getting more important for development of a vehicle because those advanced vehicles are driven by electric energy and equipped with more electric systems. In general, electromagnetic compatibility tests consist of an electromagnetic interference(EMI) test and an electromagnetic susceptibility(EMS) test. EMI test of the electric vehicles are needed not only in driving mode but also in charging mode because they must be recharged by much electric energy for driving. Depending on vehicle manufacturers, the charging device type and the location of charging device inlet in electric vehicles are various. In this paper, in order to investigate EMI of electric vehicles in charging mode in consideration of the direction of measuring antenna and the location of charging device inlet, a series of electromagnetic emission tests are conducted using three electric vehicles (neighborhood electric vehicle, electric vehicle and electric vehicle-bus). The test results show that electromagnetic emission measurements in charging mode are dependent on the direction of measuring antenna and the location of charging device inlet.

Impedance analysis of transmission line cells for EMC applications using Agros2D

When designing a TEM transmission line cell for electromagnetic compatibility susceptibility or immunity tests, its input impedance must be properly defined in order to deliver the maximum power to the device under test. The closed-form solution, relating the cell geometry with the characteristic impedance Zc, is possible only for the simplest “canonical” transmission line transverse cross-sections. The numerical methods must be used for arbitrary geometries instead. In this paper, we propose fast, robust, and accurate approach, based on fully hp-adaptive higher-order finite element electrostatic formulation. The approach is implemented in our in-house software Agros2D. The method applies for the impedance solution of an arbitrary TEM transmission line cell, any TEM transmission line with negligible losses, as well as for analyzing the effective electromagnetic properties of lossless complex stratified media.

Mercury Ion Clock for a NASA Technology Demonstration Mission.

There are many different atomic frequency standard technologies but only few meet the demanding performance, reliability, size, mass, and power constraints required for space operation. The Jet Propulsion Laboratory is developing a linear ion-trap-based mercury ion clock, referred to as DSAC (Deep-Space Atomic Clock) under NASA's Technology Demonstration Mission program. This clock is expected to provide a new capability with broad application to space-based navigation and science. A one-year flight demonstration is planned as a hosted payload following an early 2017 launch. This first-generation mercury ion clock for space demonstration has a volume, mass, and power of 17 L, 16kg, and 47W, respectively, with further reductions planned for follow-on applications. Clock performance with a signal-to-noise ratio (SNR)*Q limited stability of 1.5E-13/τ(1/2) has been observed and a fractional frequency stability of 2E-15 at one day measured (no drift removed). Such a space-based stability enables autonomous timekeeping of with a technology capable of even higher stability, if desired. To date, the demonstration clock has been successfully subjected to mechanical vibration testing at the 14 grms level, thermal-vacuum operation over a range of 42(°)C, and electromagnetic susceptibility tests.

Immunity Test for Semiconductor Integrated Circuits Considering Power Transfer Efficiency of the Bulk Current Injection Method

The bulk current injection (BCI) and direct power injection (DPI) method have been established as the standards for the electromagnetic susceptibility (EMS) test. Because the BCI test uses a probe to inject magnetically coupled electromagnetic (EM) noise, there is a significant difference between the power supplied by the radio frequency (RF) generator and that transferred to the integrated circuit (IC). Thus, the immunity estimated by the forward power cannot show the susceptibility of the IC itself. This paper derives the real injected power at the failure point of the IC using the power transfer efficiency of the BCI method. We propose and mathematically derive the power transfer efficiency based on equivalent circuit models representing the BCI test setup. The BCI test is performed on I/O buffers with and without decoupling capacitors, and their immunities are evaluated based on the traditional forward power and the real injected power proposed in this work. The real injected power shows the actual noise power level that the IC can tolerate. Using the real injected power as an indicator for the EMS test, we show that the on-chip decoupling capacitor enhances the EM noise immunity.

Electromagnetic Susceptibility Analysis of I/O Buffers Using the Bulk Current Injection Method

In this paper, we present a set of methodologies to model the electromagnetic susceptibility (EMS) testing of I/O buffers for mobile system memory based on the bulk current injection (BCI) method. An efficient equivalent circuit model is developed for the current injection probe, line impedance stabilization network (LISN), printed circuit board (PCB), and package. The simulation results show good correlation with the measurements and thus, the work presented here will enable electromagnetic susceptibility analysis at the integrated circuit (IC) design stage.

Accurate and Efficient Numerical Simulation of the Random Environment Within an Ideal Reverberation Chamber

An electromagnetic susceptibility test within an ideal reverberation chamber is numerically simulated using the moment method (MM). The random field environment within the chamber is synthesized using a superposition of plane waves that are propagating in fixed directions determined rigorously from spectral sampling theory. Randomness is introduced in the complex field amplitudes associated with each plane wave. This approach yields field statistics within a designated test region that approach ideal. Moreover, the fixed propagation directions allow very efficient calculation of the currents induced at specific test points on an equipment-under-test due to the random field realizations. MM calculations show that the proposed sampling method yields a better prediction of the statistics of the induced current while requiring far less computation time than the currently used technique of superimposing randomly propagating plane waves to yield field realizations.

Assessment of Plasma Interactions and Flight Status of the HAYABUSA Asteroid Explorer Propelled by Microwave Discharge Ion Engines

Microwave discharge ion engines “ <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$mu 10$</tex> ” are dedicated to the main propulsion on the HAYABUSA asteroid explorer. In a development program, various tests and assessments were conducted on the ion engines and the spacecraft. They include endurance tests, an electromagnetic interference susceptibility test, an interference test between the plasma and communication microwave, a beam exhaust test on the spacecraft, assessments on the plasma interference with a solar array, and so on. The spacecraft was launched in deep space by the M-V rocket in May 2003. After vacuum exposure and several runs of baking for reduction of residual gas, the ion engine system established continuous acceleration of the spacecraft toward the asteroid ITOKAWA. The spacecraft passed through a perihelion of 0.86 astronomical unit (AU) in February 2004 and an aphelion of 1.7 AU in February 2005, becoming the first solar electric propulsion system to travel this far toward and away from the Sun. The HAYABUSA succeeded in rendezvousing with the target asteroid in September 2005.

Programmable ultrawideband signal generator for electromagnetic susceptibility testing

Under Phase I of the Defense Advanced Research Projects Agency (DARPA) Networking in Extreme Environments (NETEX) initiative, Multispectral Solutions, Inc. (MSSI) was tasked with the development of a general-purpose, ultrawideband hardware simulator capable of reproducing a wide variety of ultrawideband (UWB) waveforms. The simulator, with UWB outputs from baseband through millimeter wave, was to be used for the purpose of electromagnetic susceptibility testing of legacy military radio, radar, and positioning systems. The ultimate goal of this portion of the Phase I program was the quantitative determination of those UWB parameters (e.g., frequency, power, pulse rate, pulse shape, dithering, etc.) which had the least impact on the operational performance of legacy designs. This describes the development of the MSSI NETEX UWB simulator (BFP1000).

Electromagnetic compatibility of high voltage transmission lines and the guidance of center pivot irrigation units with cornering systems

A study was carried out to determine if electromagnetic fields of high voltage transmission lines can interfere with electromagnetically guided cornering systems associated with some center pivot irrigation units. Using electromagnetic susceptibility tests, it was found that 60 hertz magnetic fields of more than approximately 500 mG (milligauss) are required to cause interference with the operation of one system. This level is significantly higher than those found near most high voltage transmission lines. It was also found that the magnetic fields at harmonic frequencies and wideband fields due to corona on the transmission line studied were insufficient to cause interference with cornering guidance systems. Observations of center pivot cornering systems operating properly near 345 kV transmission lines in Nebraska, USA, confirmed these results.

Method for determining the electric and magnetic polarizability of arbitrarily shaped conducting bodies

The paper deals with polarization properties of arbitrarily shaped conducting bodies in quasistatic electric fields and quasisteady magnetic fields within the strong-skin-effect approximation. Based on measuring the capacitance (inductance) of a field-forming system before and after introducing an arbitrary conducting body into it, a method for determining its electric (magnetic) polarizability is proposed. The method permits one to find eigenvalues and directions of the principal axes of the polarizability tensors of any conducting body. The results obtained are useful in solving two practical problems of the electromagnetic compatibility: estimation of a measurement error induced by coupling the transducers of an electric and magnetic field to the conducting surfaces, and estimation of an additional field induced by coupling the objects to the field-forming system electrodes in electromagnetic susceptibility tests.

Electromagnetic susceptibility of sound level meters

Tests of electromagnetic susceptibility (EMS) are part of the type of approval procedure for sound level meters in the field of legal metrology. Starting in January 1996 every electronic device on the European market has to have a label that indicates a certification of the device, which also includes requirements on electromagnetic susceptibility. The EMS test of sound level meters at the Physikalisch‐Technische Bundesanstalt (PTB) are performed in a radio frequency anechoic chamber. The electric field strength is 6 V/m, the frequency range is 26–1000 MHz. The frequency is varied in steps of 4% and the signal is modulated with 1000 Hz (m=80%). An acoustical signal is applied to the sound level meter and the difference of the displayed levels with and without the electromagnetic field has to be within specified tolerances (0.5 to 2 dB). At the moment not all types of sound level meters comply with these tolerances; with instruments under test deviations up to 18 dB had been observed. The present test proc...

A Numerical Method for Near-Field Array Synthesis

A numerical method for near-field array synthesis is developed for arbitrary array geometries. The intended application is for generating a planar field in a test volume for electromagnetic susceptibility testing, but the method is valid for arbitrary field distributions. A uniqueness theorem is utilized to allow the field conditions to be enforced on the surface of the test volume rather than throughout the volume. The synthesis method is a least-squares solution with a constraint on the source norm; the constraint keeps the field small outside the test volume. Numerical results are shown for the case of synthesizing a plane wave in the near field of an array of line sources.

Electromagnetic Susceptibility Testing Techniques for Airborne Equipment

All airborne equipment is tested for self-generation of interference and for susceptibility to fixed levels of interference as defined by various military and industry specifications. The susceptibility tests fall into two broad categories, conducted and radiated, extending from 50 cps to 10,000 Mc, and often including special magneticfield and transient requirements. This paper will discuss the various types, methods, and limitations of the various tests.