This top-level technical and scientific event is the most important English-speaking EU annual EMC symposium and exhibition. The program may be downloaded here: https://www.emceurope2018.org/footer/final-programme-opt.pdf
It travels always to a different EU country. About 50% of the submitted papers were rejected in the review process. Close to 600 international participants gathered, including 22 exhibitors. This year’s location was right in the center of Amsterdam, August 27 to 30, 2018. The chairman was Prof. Dr. Frank Leferink (University of Twente / Enschede and Thales Global EMC Authority, the Netherlands).
Photo 1 – Opening session (courtesy, Cees Keyer ©2018)
Photo 2 – Exhibition (courtesy, Cees Keyer ©2018)
Workshops and Tutorials covered the first day Monday, with mostly Automotive EMC, case studies from shipboard EMC, EMP, lightning protection, IEMI impact on civil infrastructures, low frequency EMI, DIY consulting, paper publishing advice and basics on EM-field related test standards.
Very exciting complete sessions / oral contributions/papers/ posters updated on:
Metrology Research, Sources of Uncertainties in EMC Test Facilities
- Development and Applications of a Fiber-Coupled Atom-Based Electric Field Probe
- Measurement of Radio-Frequency Radiation Pressure: The Quest for a NEW SI Traceable Power Measurement
- Uncertainties in Rydberg Atom-based RF E-field Measurements Broadband Rydberg Atom-based RF E-field Sensor / Standard (ca. <100 MHz to 1 THz, low V/m to high kV/m)
- High-resolution near-field imaging and far-field antenna measurements with atomic sensors
National Institute of Standards and Technology, USA (Christopher L. Holloway et al., Session: E-Field Sensing, Tuesday morning)
This is a world novelty and breakthrough in measuring EM E-Fields, predominantly in frequency domain. The Rydberg atom-based electromagnetically-induced transparency is a new, fundamentally different approach to RF E-field metrology. Here the frequency application range is greatly expanded over conventional sensors. There is basically no unknown or uncontrolled interaction/perturbation any more of the field probe with the “to be measured field”. All can be calculated / simulated. Additionally, low measurement uncertainty exists in the % range. Two special, different laser systems shine through a small glass vapor cell with low gas pressure, e.g. rubidium atom vapor. Using quantum physics effects (excited amplitude state transitions, probe frequency detuning, dipole moment of the transition and the Planck’s constant) the absolute value of the E-field can now be computed.
The sensor is still in an R&D state. Material still costs several hundred thousand dollars. Work is however outsourced to create a lower cost, field deployable, commercial product in the next years.
- A study of electric-field measurement disturbances brought by probe supports
France: Société Industrielle d’Etudes et Protections Electroniques (SIEPEL), (Ludivine Le Bars et al.)
This paper deals with interferences induced by dielectric supports/masts on E-field measurements performed with conventional isotropic electric field probes (150 MHz to 1GHz, mast/probe distance min. 10cm to 40cm-> errors up to about 5 dB total E-field). Such measurement uncertainties have been demonstrated in reverberation as well as in absorber lined chambers.
- Evaluation of Numerical Methods for the Simulation of Real (EMC) Test Facilities for Low-Frequency Magnetic Fields Measurements (Maik Rogowski et al., Leibniz Universität Hannover, Germany)
This paper supports scientifically current international lower frequency standardization efforts (reintroducing H-field emissions below 30MHz). The influence of characteristic material properties of the ground plane floor (electrical conductivity and relative permeability) on measurement results of magnetic fields (e.g. CISPR 16-1-4/AMD1/FRAG2 ED4, 9 kHz to 30 MHz, d=3m) in the low-frequency range of up to 1MHz seems to be important to meet the discussed new volumetric +/-4dB NSA acceptance criterion.
Simulation results compare favorably well to round robin test measurements from different Semi Anechoic Chambers (SAC).
In particular the electrical conductivity of the ground plane material choice has a strong influence on the simulation/performance results. Relative permeability, on the other hand, has only an effect in the very low frequency range. This means in test facilities such as OATS and SAC, the results can differ significantly (up to ca. 4 dB at 9 kHz / 2.5 dB at 1 MHz) depending on the material properties of the ground plane. This may be critical for successful “EM-Field” test facility qualification / verification. Industry wants to continue using existing chambers.
Critical Cases of RFI Introduced by LEDs (SMPS)
- Statistical Characteristics of Radiation Noise from LED Lamps and Its Effect on Wireless Medical Telemeters
National Institute of Information and Communications Technology (NICT), Tokyo, Japan; Department of Medical Safety Engineering, Kitasato University, Kanagawa, Japan (Sazu Arie et al.)
An electrocardiogram unit with wireless (445 MHz / 1mW/ FSK/ 12.5 kHz) patient monitor in a hospital examination room was jammed by LED Lamps with an integrated power supply system (CISPR 15 ED. 8.0 compliant). The LED location was nearby, less than 3m away, under the ceiling of the patient room. This is common hospital installation practice in Japan. A video from that scene dramatically showed a cardiovascular completely healthy patient without the LEDs on. Turning the LEDs on, the patient showed critical, EMI induced, irregularities in the ECG Signal. In a detailed, well controlled EMC lab investigation, the interference effect was reproducible with a transmit horn antenna and Gaussian noise modulation and receive amplitude probability detection at that frequency. As a result the S/N ratio between LED Noise and the threshold of the wireless monitor was clearly much too low. Only average power was considered, peak powers would have made it even worse. The necessary safe S/N ratio is estimated to be about 20dB. Investigations on spatial noise distribution around typical Japanese medical LED Lamp systems need further R&D before CISPR 15 may have to be amended.
- André Canrinus informed the author at the conference about a recent US Coast Guard (US Department of Homeland Security) Marine Safety Alert 13-18, Aug. 15, 2018 Washington, DC, USA, Inspection and Compliance Directorate:
“On potential LEDs interference of VHF-FM Radio and AIS Reception”
- Monitoring of Power Measured by Static Energy Meters for Observing EMI Issues (University of Twente, Enschede, the Netherlands)
There is an interesting side remark by the authors on LED / Dimmer EMI on the accuracy of smart energy meters (positive deviation makes the consumer pay unjustified higher electricity bills):
Research has shown that in some cases the static meters can give faulty energy readings, positive and negative, if static meters are loaded with pulsed currents. Controlled experiments on static meters show that they can present faulty readings. When using static meters in a three-phase standardized power supply setup, loaded with a string of compact fluorescent lamps (and light emitting diode (LED) lamps in combination with a dimmer, static meters show a positive deviation of 276% and a negative deviation of −46% compared to conventional electromechanical energy meters. The experimental results show that the tested static meters using a standard building power supply gave maximal positive deviations of +582% and negative deviations of −32% when loaded with compact fluorescent lamps (CFL) and LED lamps in combination with a dimmer for a one-phase test setup. Because the energy consumption of LED and CFL lights is low, these experiments were carried out by measuring over a period of 1 to 2 weeks.
Automotive Issues
- The Need for a Risk-Based Systems Engineering Approach in Automotive EMC Engineering (Alastair R. Ruddle et al., MIRA UK)
The range and complexity of technologies that are now being deployed in the automotive industry are increasing at an unprecedented rate. Furthermore, the pace of change is becoming so fast that standardization activities struggle to support these on-going developments.
The inter-relationships between system safety, cyber security and functional performance suggest that a unified approach exploiting and adapting the risk management techniques of functional safety could equally well be used to address they key system performance aspects of safety, security and functionality, including the specific implications of electromagnetic effects for these areas.
The adoption of more robust systems engineering practices and a risk-based approach will be key to meeting the challenges of future automotive EMC engineering. Such an approach would also help to address the limitations of simple rules-based approaches to EMC design.
- An Investigation into Alternatives to the CISPR 12 Full Vehicle Measurement Method (Max Paterson, et al., MIRA UK)
The current CISPR 12 method has been shown to under estimate vehicle radiated emissions by up to 30 dB. This paper describes and presents a possible alternative test method to the current CISPR 12 procedure. The initial results from investigations into the use of the ’Test Wire Method’ are presented, where a reduction in the average error of approximately 8dB compared to the CISPR 12 method has been recorded.
Blog author’s comment: ’Test Wire Method’ is a kind of tailored transmission line approach e.g. on the chassis / car body, similar what some people in military testing use. It is predominantly based on surface current coupling, rather than complete vehicle field illumination.
Radio Noise Floor Measurements Below 30 MHz
- Issues Concerning Radio Noise Floor Measurements using a Portable Measurement Set-up (Koos (T. W. H.) Fockens et al., University of Twente, Enschede / VERON EMC Committee Arnhem, the Netherlands)
An investigation into requirements for measuring the radio noise floor, using portable equipment, shows issues in the field of sensitivity, calibration accuracy, and directivity, besides the general requirements as described in Recommendation ITU-R SM.1753-2. A minimum sensitivity requirement for antennas is derived, and causes of uncertainty in the calibration of E-field rod antennas are analyzed. E-field rod antennas were found to be unsuitable for noise floor measurements when they are not grounded using low-impedance. H-field loop antennas do not show those accuracy problems, but require to be tuned in frequency for sufficient sensitivity, and there is a need to measure in two orthogonal directions with vector adding of both results to produce a radio noise floor that is direct comparable with the MMN levels as mentioned in Recommendation ITU-R P.372-13.
Blog author’s comment: Background noise 9 kHz to 30MHz has been increasing, sometimes by orders of magnitude, over past decades. Under CE requirements there is hardly any testing of electronic products for radiated emissions in this frequency range. As a consequence sensitive and important radio services (see ITU for frequency allocations) in these bands are now increasingly struggling with RFI and reduced communication range, based on worsening S/N ratio. This is particularly true for urban areas. EMC emission limits / test procedures, radiated interference scenarios of “RFI producing equipment being always on” / simultaneously transmitting / interfering with multiple TX sources, are now being reanalyzed by CISPR H. Moreover industry slowly recognizes some problems with uncontrolled intra-equipment interference based on miniaturization and broadband issues. All this may drive reintroduction of radiated emission limits in various product areas below 30MHz.
EMF Effect Observation
- Observation of Abnormal Behavior of Cows Exposed to Electromagnetic Fields (Frits Buesink et al., University of Twente, Enschede, the Netherlands)
The question as to whether electromagnetic fields far below the considered safe exposure (ICNIRP, Recom.1999-519-EU) limits can be experienced by living beings could be answered with a careful “yes” for the observed situation of cows avoiding an area with a mains related electric field characterized by the presence of high frequency transient voltage spikes. These were generated by a newly commissioned photo voltaic (PV) installation on a Dutch farm.
Military Land Army Vehicle
- EMC performances of a Land Army vehicle to respect integrated radios reception sensitivity: Typical performances needed for “Fitted For Radio (FFR)” land vehicle (Alain Alcaras, Thales communications and security, France)
The EMC performances of a land vehicle become difficult because of the two main aspects.
First aspect, the number of radio frequency subsystem is growing in vehicle. Second aspect, the number of electronic/electric subsystem is growing too in vehicle. Since these subsystems have important impact on the vehicle missions, the EMC performances is critical.
This paper presents some numerical examples of EMC issues experienced by Thales. These examples highlight the EMC risks for military land vehicle. It is shown that the EMC compliance of subsystem and product is not sufficient to ensure the radio performance of vehicle, in particular for the desensitization risk of radio reception. So, the Fitted For Radio performance of vehicle (FFR vehicle certification) is discussed, considering that the common EMC standards are not sufficient to ensure this performance. Also, this paper indicates some tools allowing an EMC vehicle designer to make a performant (certified) FFR vehicle (analytical, experimental and standard tools).
When we consider a military land vehicle integration, the greater EMC risk is the radio desensitization by the parasitic radiation of electronics, even if the equipment are compliant to military standards. This paper shows also that the use of increasing number of COTS equipment (only compliant to civilian standard) leads to a great EMC risk for military land vehicle and leads to an unacceptable expected combat electromagnetic environment.
This paper shows that the vehicle compliance to AECTP 501 or MIL-STD-461 standard is not sufficient to certify military land vehicle as FFR vehicle. To certify a FFR vehicle in terms of radio desensitization risk, these specifications are needed:
- The vehicle must be qualified following the AECTP 507 standard process. The limits have to be defined by the actual radio desensitization threshold (§ V.B).
- Vehicle Equipment (platform and payload) must be:
- Qualified following the NRE02 test of AECTP 501 applying specific limits consistent with the radio desensitization threshold (§ III.B).
- Qualified following the NCE05 test of AECTP 501
- The cable length must be as short as possible; the cable must be stuck closely to the ground; the cable must be shielded if it is installed outside the vehicle or inside a no shielded vehicle.
Standard ESD Testing Under Tropical Humidity Conditions
- Implementation of IEC 61000-4-2 standard testing under tropical humidity for recommendation to Amendment of International Standards (Hardiles et al., National Standardization Agency of Indonesia, Indonesia)
Humidity is one of the essential environmental factors that can affect the performance of electronic appliances. The yearly average of relative humidity in tropical countries, such as Indonesia, is higher than in subtropical countries. The data shows that the average relative humidity in 11 major cities in Indonesia from 2016-2017 is above 70%. Some IEC standards set different testing requirements for tropical and non-tropical climate condition. IEC 61000-4-2 as a standard for electrostatic discharge
(ESD) immunity test only set a single range of relative humidity, 30% to 60%, as the climatic condition requirement. Although this requirement can be applied in the testing laboratory, however, this does not match with the actual climate condition in Indonesia as a tropical country. This paper investigates the effect of relative humidity in air discharge ESD testing to the performance of DVD-Player as the equipment under test (EUT).
The measurement showed that the EUT experienced faster initial performance degradation in higher relative humidity. These findings are expected to find their way into the applicable ESD standards.
I am hoping you profit from this and enjoy my selection. It was a long, interesting and educational week in Amsterdam. The next (EU traveling road show) event will be EMC Europe 2019 in Barcelona, Spain, September 2 to 6, 2019.
