Commission E (Electromagnetic Noise and Interference)
Activity Report (August 2005 to February 2006)
March 1, 2006
1.1 Domestic Conferences and Meetings
On September 8 – 9, October 27 – 28, November 25, December 9, 2005,
and January 16, 2006, the technical committee meetings on EMC organized by IEICE
in cooperation with URSI-E were held in
1.2 International Conferences and Meetings
The session on Atmospheric
electricity and electrical effects was held at Scientific Assembly of the
International Association of Meteorology and Atmospheric Sciences (IAMAS) 2005
The 2005 International Symposium
on Microwave, Antenna, propagation and EMC Technologies for Wireless
Communications was held in
The International Conference on
Lightning and Static Electricity (ICOLSE) 2005, was
The EMC Europe Workshop was held
The 15th International
Conference on Electromagnetic Disturbances was held in
1.3 Future International Conferences and Meetings
1. The 17th International Zurich Symposium on Electromagnetic Compatibility will be held in Singapore, on February 28 – March 3, 2006.
2. The Pan-Pacific EMC Joint Meeting, organized by IEICE EMC Technical Committee, will be held in Okayama on May 25 – 26, 2006.
3. The 18th International Wroclaw Symposium and Exhibition on Electromagnetic Compatibility will be held in Wroclaw, on June 28 – 30, 2006.
4. The 4th Asia-Pacific Conference on Environmental Electromagnetics will be held in Dailan on August 1-4, 2006.
5. Progress in Electromagnetics Research Symposium (PIERS) 2006- Tokyo will be held in Tokyo, Japan, on August 2-5.
6. 2006 International Symposium on Electromagnetic Compatibility will be held in Portland, on August 13-17, 2006.
7. The 7th edition of EMC Symposium will be held in Barcelona on September 4-8, 2006.
8. The 16th International Conference on Electromagnetic Disturbances in Equipment and Systems will be held in Kaunas, Lithuania, on 27 September, 2006.
2. Technical Trends
Electrostatic discharge (ESD) events due to metal objects electrified with low voltages give a fatal electromagnetic interference to high-tech information equipment. In order to elucidate the mechanism, with a 6-GHz digital oscilloscope, we previously measured the spark current through a hand-held metal piece from a charged human body, and proposed a current calculation model. In the present study, we have investigated the properties of a spark discharge itself through a hand-held metal piece from a human body electrified with low voltage below 1000 V. From the measured discharge current waveform and the gap voltage calculated from the above-mentioned current calculation model, we have derived the gap resistance with respect to time, and estimated the gap length using a spark resistance formula. As a result, we have found that for the charge voltage from 200 V to 1000 V, the gap length approximately increases with the charge voltage, while the corresponding gap breakdown field is almost kept constant. The findings were supported by the experimental results that other researchers obtained with their different set-ups consisting of metal electrodes. (Dr. Y. Taka, et al.)
The electromagnetic noise caused by an electrostatic discharge (ESD) of charged metals is a major source of malfunction to high-tech equipment. The ESD testing scheme is being specified in the IEC61000-4-2, which prescribes the current waveform from an ESD-gun through an IEC recommended current detector (Pellegrini calibration target). Our research group previously presented an FDTD modeling of an ESD-gun for contact discharge. For air discharge that provides an actual ESD event, however, the IEC does not give any detailed information about the immunity testing. In the present study, in order to simulate an air discharge from an ESD gun, we have incorporated a lumped parameter spark resistance based on the Rompe-Weizel formula with the above-mentioned FDTD modeling of an ESD gun. The effectiveness of our proposal has been shown in comparison with wide-band measurement of the discharge current waveforms for air discharge to an SMA connector and a ground plate. (Prof. O. Fujiwara, et al.)
Wideband Measurement of Discharge Current due to Air Discharge of an ESD-gun
According to the IEC 61000-4-2 for electrostatic discharge (ESD) immunity testing, an ESD-gun with charge voltages above 2 kV is used to inject a discharge current onto a device under test. The current waveform is being prescribed in the IEC standard for contact discharge, but is not specified for air discharge due to its poor reproducibility, although the air discharge gives a severe immunity testing. Furthermore, it is well known that ESD events with low charge voltages below 1 kV cause serious failure to high-tech equipment, while its mechanism remains unknown. In the present study, in order to clarify the severity of low voltage ESD events, using a 12-GHz digital oscilloscope, we have measured current waveforms through air discharge of the ESD-gun with charge voltages from 200V to 1 kV. As a result, we have found that the current peak and rise time become higher and shorter, respectively, in comparison with those for contact discharge, whose tendency was almost the same as the results for charge voltages below 1 kV we previously obtained with a 6-GHz digital oscilloscope. It has also been shown that the rise time measured for charge voltages below 500 V reaches the limit of measurement (35 ps). (Prof. O. Fujiwara, et al.)
Characteristics of Discharge currents caused by ESD-Gun for IEC Immunity Testing
Peak current and rise time have been observed for contact and air discharge of an ESD-gun with various charge voltages. As a result, we have found that for charge voltages below 1kV approaching speed of the ESD gun does not almost affect the discharge current, and also that the current peak and rise time become higher and shorter, respectively, in comparison with those for the contact discharge. (Prof. O. Fujiwara, et al.)
General Synthesis Modeling for Complex Technical and Biological Systems
A method of circuit model synthesis for an arbitrary complex technical or biological system has been presented. The method is based on a rather general matrix-operator representation of a system. Conditions of sufficient model synthesis have been formulated as a theorem and then have been proved. The theorem is concerned with linear, nonlinear, non-stationary and discretization (multiply-valued) operators. The first three types of operators permit us to build an unbalanced circuit-type model on microelectronic element basement: ARC-linear, one-port nonlinear, and one-port stationary elements. It has been shown that general nodal representation of a system circuit-type model can be obtained on the basis of initial description of the original system. This way has been proposed to be the most convenient for complex system modeling. Some examples of method application and comparisons with well-known algorithms have been given. (Prof. M. Hayakawa, et al.)
Analysis on Sub-aerial Electric Field Radiated by a Unit Electric Current Source in the Ground
The expressions of sub-aerial electric field excited by a unit electric current source in the ground, have been derived using the method of image charges, and we have studied the attenuation and radiation directivity of the electric field from the current source. Lower frequency below ELF (extremely low frequency, less than 1kHz) is our interest. The main emphasis of this paper is the study on the condition and possibility for detecting seismogenic emissions for various orientations of the electric current source (from horizontal to vertical). (Prof. M. Hayakawa, et al.)