Osamu Fujiwara and Akira Sugiura

1. Conferences

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 Kyoto, Akita, Tokyo, Gifu and Fukuoka, respectively. The numbers of presented papers were 22, 26, 8, 13 and 10, respectively. On November 1 – 2, the EMC workshop was held in Izu. The number of lectures was 11.　On August 22 – 23, 2005, a special session on natural noises was planned in IEE Japan Society Meeting, in Tokyo. The number of invited talks was 8. On January 11 – 12, 2006, 2006 Winter Meeting organized by Society of Atmospheric Electricity of Japan was held in Tokyo. The number of papers presented was 52.

1.2 International Conferences and Meetings

1. The session on Atmospheric electricity and electrical effects was held at Scientific Assembly of the International Association of Meteorology and Atmospheric Sciences (IAMAS) 2005 in Beijing, China on August 2-7, 2005.

2. The 2005 International Symposium on Microwave, Antenna, propagation and EMC Technologies for Wireless Communications was held in Beijing, China, on August 8 – 12, 2005.

3. The International Conference on Lightning and Static Electricity (ICOLSE) 2005, was held in Washington, U.S. on September 18-23, 2005.

4. The EMC Europe Workshop was held in Rome, on September 19-21, 2005.

5. The 15th International Conference on Electromagnetic Disturbances was held in Bialystok, Poland, on September 21-23, 2005.

1.3 Future International Conferences and Meetings

1. The 17^th 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 18^th International Wroclaw Symposium and Exhibition on Electromagnetic Compatibility will be held in Wroclaw, on June 28 – 30, 2006.

4. The 4^th 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 7^th edition of EMC Symposium will be held in Barcelona on September 4-8, 2006.

8. The 16^th International Conference on Electromagnetic Disturbances in Equipment and Systems will be held in Kaunas, Lithuania, on 27 September, 2006.

2. Technical Trends

Influences on electromagnetic environment by high-speed power line communication (PLC) system

High-speed power line communication (PLC) system uses the signal whose power spectra include an HF band. For its electromagnetic radiation, therefore, some groups in Japan have been investigating the influence on electromagnetic environment. For example, Ministry of Internal Affairs and Communication (MIC) has been holding the "Study Group on High-Speed Power Line Communications" since January 2005, and, recently, MIC decided that the Information and Communications Council would deliberate upon "Limits and methods of measurement concerning facilities for high-speed power line communications." The researchers at universities and the engineers of the related companies have also presented the investigation results, which are 1) Investigation of influence on AM signal, 2) Evaluation of electric field using a wooden house, 3) Calculation of balance-unbalance conversion factor and electromagnetic field, 4) Measurement of LCL and common mode impedance at outlet in house, 5) Equivalent representation of indoor power, and etc. (Prof. N. Kuwabara)

EMC test method

EMC regulation for information technology equipment (ITE) was started by VCCI 20 years ago. Some problems concerning with EMC test method was presented and discussed by VCCI members. The subjects were 1) Distance dependence of the electric field measured by a VCCI specifying method, 2) Semi anechoic chamber satisfying the requirement of CALTS, 3) Influence of EUT tables for the radiating electric field test, 4) Improvement of the test reproducibility by stabilizing the line impedance, 5) ISN for testing emission at telecommunication ports, and 6) Influence of the signal line poison in a multi-layer PCB. (Prof. N. Kuwabara)

Gap Breakdown Field in Contact with Hand-Held Metal Piece from Charged Human Body

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.)

FDTD Simulation of Air Discharge with an ESD-gun

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.)