Improved electromagnetic compatibility standards for the interconnected wireless world

© 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.The future is wireless, a world where everything is interconnected. However, the current standards for ensuring the electromagnetic compatibility (EMC) and the coexistence of such wireless systems urge for a major update. It is shown how novel statistical approaches based on the amplitude probability distribution detector and time-domain measurements are better suited for estimating the degradation caused by electromagnetic interferences on digital communication systems than the established practice of determining compliance according to the quasi-peak detector levels using a pass/fail criterion. Therefore, a redefinition of the test methods and of the compliance requirements in terms of EMC standards must be a priority of the international standardization bodies. Finally, a discussion of the fundamental challenges involved in this standardization breakthrough for EMC is delivered.Postprint (author's final draft

Benefits of full time-domain EMI measurements for large fixed installation

It is difficult to properly evaluate the electromagnetic disturbances generated by large fixed installations because of, i.e., the background noise, unsteady emissions and transient interferences. Those challenging EMC issues have been recently studied in European research projects on improved test methods in industrial environments. In order to overcome traditional in-situ EMI measurement troubles, a novel time-domain methodology is proposed and used in a real fixed installation with large machinery. Firstly, a comparison between the developed measurement system, using an oscilloscope, and an EMI receiver is done in some test-cases for validation purposes. After verifying the accuracy of the measurements, we proceed with the measurement campaign applying the full time-domain methodology. The main benefits of employing the time-domain system are emphasised through the results. It was observed that the some remarkable advantages of the time-domain approach are: triggering by disturbance events, extremely reduce the capturing time, identify on real time the worst emissions modes of the EUT, avoid changes at the background noise and perform simultaneous multichannel synchronous measurements.Postprint (published version

A single antenna ambient noise cancellation method for in-situ radiated EMI measurements in the time-domain

This paper presents a single antenna ambient noise cancellation method for in-situ radiated emissions measurements performed using an entirely time-domain approach and the sliding window Empirical Mode Decomposition. The method requires a pair of successive measurements, an initial one for characterizing the ambient noise and a final one for the EMI measurement in the presence of ambient noise. The method assumes the spectral content of the ambient noise is stable between both measurements. The measured time-domain EMI is decomposed into a finite set of intrinsic mode functions. Some modes contain the ambient noise signals while other modes contain the actual components of the EMI. A brute-force search algorithm determines which mode, or combination of modes, maximize the absolute difference between the magnitude of their spectrum and the ambient noise levels for every frequency bin in the measurement bandwidth. Experimental results show the effectiveness of this method for attenuating several ambient noise signals in the 30 MHz – 1 GHz band.Postprint (published version

On-board compact system for full time-domain electromagnetic interference measuraments

Postprint (published version

Alternative conducted immunity tests

Conducted immunity tests are always performed by the use of CDNs in laboratories in accordance with the standard EN61000-4-6. However, it is not always possible to use CDNs because of some limitations. If the EUT (Equipment Under Test) has large dimensions or high currents, it is not, most of the time, possible to send it to an EMC laboratory or to use CDNs during the test. As a consequence, usage of BCI probes is inevitable in industry. In this paper, we compared the laboratory setup installed with CDNs and alternative setups installed directly on mains without any CDNs in terms of loop impedances and injected loop currents. We also established a link based on the loop impedances and the injected currents on the test loops between the two setups. Finally, a first serious step was taken to establish the fundamentals of alternative conducted immunity tests based on the impedance measurements of test loops for industry.Postprint (published version

Alternative conducted emission measurements on mains without LISNs

Conducted emission tests are always performed by the use of LISNs in laboratories in accordance with CISPR22, CISPR11 and other similar standards. However, it is not always possible to use LISNs because of some limitations. If the EUT (Equipment Under Test) has large dimensions or high currents, it is not, for most of the time, possible to send it to an EMC laboratory or to use LISNs during the test. As a consequence, usage or development of alternative conducted emission test methods is inevitable in industry. In this paper, we made conducted measurements on actual EUTs in alternative environments whose impedances are different from the standard LISN impedance and continued to establish the fundamentals of alternative conducted emission tests based on the impedance measurements of the EUT, supply and used cables. We also established the correlation, on the basis of impedance measurements, between these alternative conducted emission test method and the reference conducted emission test method.Postprint (author's final draft

Waveform characterization of calibration-pulse generators for EMI measuring receivers

© 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.This paper presents the waveform characterization of calibration pulse generators intended to evaluate the response to pulses of the weighting detectors in CISPR 16-1-1 measuring receivers. First, the standard requirements of the reference pulses are described, and the pulse generators calibration methods based on waveform measurements are briefly discussed. Then, high-resolution time domain measurements are used for characterizing the waveforms of a commercial calibration-pulse generator in terms of rise/fall time, pulse width, mean voltage of the upper state, repetition frequency, and area. Moreover, the results above are used for estimating the spectral density of the impulses, their corresponding quasi-peak level, the pulses bandwidth, and the breakpoint frequencies. Finally, the measurement uncertainty is estimated for CISPR bands A, B, and C/D. Results are in good agreement with other calibrations performed during an intercomparison exercise and the uncertainty satisfy the target ±0.5 dB and 1% given in standards for the impulse area and pulse repetition frequency respectively.Postprint (author's final draft

RFID systems in medical environment: EMC issues

RFID is a promising technology in the healthcare area in order to improve patient safety and increase efficiency and reduce costs in the daily healthcare work. This paper analyzes the available literature regarding both interference of RFID systems in medical equipment and the interferences of medical equipment on RFID systems. The conclusion of this analysis is that is necessary to develop standards in order to protect medical equipment from RFID interferences, and standards to plan the deployment of RFID installations taking into account electromagnetic compatibility issues.Postprint (published version

Waveform Approach for Assessing Conformity of CISPR 16-1-1 Measuring Receivers

An alternative approach for assessing the conformity of electromagnetic interference measuring receivers with respect to the baseline CISPR 16-1-1 requirements is proposed. The method’s core is based on the generation of digitally synthesized complex waveforms comprising multisine excitation signals and modulated pulses. The superposition of multiple narrowband reference signals populating the standard frequency bands allows for a single-stage evaluation of the receiver’s voltage accuracy and frequency selectivity. Moreover, characterizing the response of the weighting detectors using modulated pulses is more repeatable and less restrictive than the conventional approach. This methodology significantly reduces the amount of time required to complete the verification of the receiver’s baseline magnitudes, because time-domain measurements enable a broadband assessment while the typical calibration methodology follows the time-consuming narrow band frequency sweep scheme. Since the reference signals are generated using arbitrary waveform generators, they can be easily reproduced from a standard numerical vector. For different test receivers, the results of such assessment are presented in the 9 kHz–1 GHz frequency range. Finally, a discussion on the measurement uncertainty of this methodology for assessing measuring receivers is given.Postprint (author's final draft

Simulación electromagnética FD-TD : una ayuda al diseño en compatibilidad electromagnética

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