Commission E (Electromagnetic Noise and Interference)
Activity Report _November 2003 to March 2004
March 10, 2004
Osamu Fujiwara and Akira Sugiura
1. Conferences
1.1 Domestic Conferences and Meetings
(1) On November 18, December 5 and January 20, the technical committee meetings on EMC organized by IEICE were held at Tokyo Institute of Technology, Gifu University and Tokyo Metropolitan University, respectively. Numbers of presented papers were 19, 13 and 27, respectively. The same meeting will be held at Kikai-Shinko Kaikan on March 12, 2004.
(2) The 70th conference was held on January 8 and 9 at Self Defense Academy (Boei Daigakko) in
Yokosuka.
(3) The 16th Technical Committee Meeting on EMC organized by IEEJ was held at Osaka University on January 16, 2004.
1.2 International Conferences and Meetings
(1) Asia-Pacific Conference on Environment Electromagnetics (CEEM’2003) was held on November 4-7, 2003 in Hangzhou, China.
(2) 2003 Asia-Pacific Conference (APMC’03) was held on November 4-7, 2003 in Seoul, Korea.
1.3 Future International Conferences and Meetings
(1) The Progress in Electromagnetics Research Symposium (PIERS 2004) will be held from March 28 to 31, 2004 in Pisa, Italy.
(2) 2004 International Symposium on Electromagnetic Compatibility, Sendai (EMC’04/Sendai) will be held from June 1 to 4, 2004 in Sendai, Japan. The deadline of paper submission is November 15, 2003, and electronic submission is available via http://www.ieice.org/emc04/
(3) The 17th International Wroclaw Symposium and Exhibition on Electromagnetic Compatibility will be held from June 29 to July 1, 2004 in Poland. The summary should be submitted by December 1, 2003.
(4) 2004 IEEE International Symposium on Electromagnetic Compatibility will be held from August 16 - 20,2004 in Santa Clara, USA.
(5) 2004 Asia-Pacific Radio Science Conference (AP-RASC’04) will be held from August 24 to 27, 2004 in Qingdao, China. The paper submission deadline is March 31, 2004.
(6) The International Symposium on Electromagnetic Compatibility, EMC Europe 2004 will be held from September 6 to 10, 2004 in Eindhoven, The Netherlands.
(7) 6th International Workshop on Physics of Lightning will be held from May 3 through 9, 2004 in Saint-Anne, Gadeloupe, France.
(8) 27th International Conference on Lightning Protection will be held from September 13 to 16, 2004 in Avignion, France.
2. Technical Trends
The establishment of a research center for joint study in Darwin, Australia is under way. Lightning Research Group of Osaka University (LRGOU) has been conducting field campaigns of lightning observations in Darwin, Australia since 1995 continuously. The main objectives of campaigns are to develop the VHF broadband interferometer and to investigate the mechanism of lightning discharges, especially inside thunderclouds. The contribution to collect ground truth for TRMM/ LIS observations is also one of objectives. It is concluded that the campaigns are satisfactory and fruitful from the aspects of original objectives. To realize the permanent observatory, Osaka University and LRGOU would like to organize an international workshop in coming March. LRGOU has now started the preparation for the workshop. (Prof. Z. Kawasaki)
Winter lightning on the Sea of Japan and related phenomena (sprites, Trimpis, ELF transients) has been investigated in order to study the atmosphere-ionosphere coupling. (Prof. M. Hayakawa)
The study on the earthquake prediction using the VAN method and ULF geomagnetic, and geopotential measurement at Izu, Iwate, Matsusiro, and Taiwan have been conducted. The main attention was paid to new signal analysis. (Prof. T. Hattori)
Broadband spectral observations have been conducted in the VHF band regularly in Chiba, Japan to investigate any natural radiation and/or anomaly of propagation of broadcasting waves. It has been found that distant oversea TV broadcasting waves can sometimes propagate to the observatory. The propagation of these TV waves has been classified and those mechanisms have been investigated. A possibility of natural radiations associated with earthquakes by receiving broadband white noise has been presented. (Prof. T. Takano)
A network of seismogenic ULF emissions in the Kanto area, and a nation-wide network of VLF/LF subionospheric wave have been established in order to find the seismic effect onto the ionosphere for short-term earthquake prediction. (Prof. M. Hayakawa)
The precursors of the earthquake related to ELF electromagnetic wave below 50Hz has been investigated. Schumann resonance was observed at Nakatsugawa, and VLF transmitters (NWC, 19.8kHz and JG2AS, 40kHz) wave observed at Kasugai. (Prof. K Ohta)
Schumann resonance (SR) and global warming
Using the ELF observation at Moshiri, the correlation of SR intensity with temperature in the tropics and middle latitudes has been analyzed to study the effectiveness of SR as a global thermometer. (Prof. M. Hayakawa)
Immunity/susceptibility test method
In order to make immunity/susceptibility characteristics against radio-frequency electromagnetic fields clear, a new test method of using electromagnetic fields rotating a very low rate in two-dimensional is being proposed, demonstrating the characteristics depicted in visualized three-dimensional map and applying it into a four-septum TEM cell. (Prof. Y. Kami)
Antenna factor of EMI measuring antennas:
Traditionally, radio disturbances emitted from electronic equipment have been measured with an EMI antenna. And the level is expressed in terms of the electrical field strength that can be obtained by multiplying the received voltage by the antenna factor of a measuring antenna used. However, the antenna factor may vary in magnitude with the antenna height above a ground plane due to the ground reflection. Hence, to improve the measurement uncertainty, the CISPR (International Special Committee on Radio Interference) has recently decided to use the free-space value of the antenna factor for EMI measurements. This decision seems to have a great impact on other radio measurements such as measurements on radio transmitters and EM environments. (Prof. Sugiura)
Systems and installations
New technique trends include development of the methods on measurement of radiated emission from large-scale systems, immunity testing, prediction of emission and immunity and noise proof technique. It is expected to establishment design method to realize the EMC specifications by simple calculation (add, subtract, multiply and divide) at the planning stage of systems and/or equipments. (Prof. Nitta)
Simulation of undesired noise form printed circuit board
In order to explain the undesired electromagnetic radiation from PCB, modeling of 3-dimentional FDTD simulation and experiment is being performed. It is reported that not only the common mode current dependency but also spatial radiation distribution near the tested sample should be investigated precisely. (Prof. Inoue)
APD (Amplitude probability distribution) analysis
A comparison between two different methods called RMS-AVG (Root Mean Square-Average) and APD, is being discussed in CISPR as the disturbance measurement method to evaluate the degradation of the digital wireless communication systems. Repetition pulse and Gaussian noise were added as the disturbance to the DQPSK (Differential Quadrature Phase Shift Keying) coded signal at the transmission path. The disturbance effects on BER (Bit Error Rate) and on each reading by the two methods were obtained quantitatively. The comparison shows that both methods account for the disturbance effect on a digital wireless communication system. (Dr. Y. Ishigami)
GTEM Cell
A GTEM (gigahertz transverse electromagnetic) cell is used for immunity and emission tests. The correlation between the immunity-test result in a GTEM cell and that in an anechoic chamber were examined theoretically. The average electric fields of the EUT surfaces in a GTEM cell and an anechoic chamber were calculated by using the FDTD method in order to evaluate a suitable installation and size of EUT in the GTEM cell. When the size of EUT were 10%, 20%, and 30% of the septum height, the difference in both the test result of the GTEM cell and the anechoic chamber were expected to be about 1dB, 2dB, and 2-3dB, respectively. Moreover, when the EUT surface approached the septum and floor conductor, the difference increased. (Dr. Y. Ishigami)
Reverberation chamber
In using a reverberation chamber for radiated immunity testing, it is important to determine the number of discrete steps through which the stirrer rotates and the number of probe locations for a given test volume in the chamber. This is because they affect the uniformity and calibration of the field in the test volume. Experimental evaluation for the effect of the numbers of stirrers and their steps on the field uniformity, as well as the effect of the number of probe locations on field calibration have been conducted. It has been confirmed that (1) it was possible to obtain sufficient uniformity in the field by using two stirrers; (2) uniformity was not improved greatly by using more than 100 stirrer steps; and (3) the use of a small number of probe locations increased the uncertainty in the evaluation of uniformity. (Dr. Y. Ishigami)
Calibration of electromagnetic probe
In order to calibrate an electromagnetic probe in the frequency range from 350MHz to 18GHz, a method by using open-ended waveguides has been proposed as the standard radiators. A calibration facility is established with an anechoic chamber. The uncertainty of the facility is evaluated as 0.96dB (500MHz-8.2GHz) and 1.14dB (350MHz-500MHz, above 8.2GHz) at the confidence coefficient of 95%, respectively. (Dr. Y. Ishigami)
EMC problem related telecommunication system
The increasing speed of power line communications may affect existing communication system. The studies were performed about the influences to the communication system and the characteristics of the indoor power line system. The EMC problems of the high-speed telecommunication system using unshielded twisted pare (UTP) cable were also studied for the emission from UTP cable and the countermeasure method. (Prof. Kuwabara)