Osamu Fujiwara

1. Conferences

1.1 Domestic Conferences and Meetings

On September 1, October 26 –27 and November 24, the Technical Committee Meetings on EMC organized by IEICE in cooperation with URSI-E were held in Osaka, Hachinohe and Himeji, respectively. The numbers of presented papers were 7, 25 and 6, respectively.

1.2 International Conferences and Meetings

1. The 4th Asia-Pacific Conference on Environmental Electromagnetics was held on August 1-4, 2006, in Dalian, China.

2. Progress in Electromagnetics Research Symposium (PIERS) 2006 - Tokyo was held on August 2-5, 2006, in Tokyo, Japan.

3. 2006 IEEE International Symposium on Electromagnetic Compatibility was held in on August 13-17, 2006, Portland, USA.

4. The 7th edition of EMC Europe Symposium was held on September 4-8, 2006, in Barcelona, Spain.

5. 2006 Korea-Japan AP/EMC/EMT Joint Conference (KJJC) was held on September 23-24, 2006, in Kanazawa, Japan.

6. XVI International Conference on Electromagnetic Disturbances (EMD’2006) was held on September 27 – 29, 2006 in Kaunas, Lithuania.

1.3 Future International Conferences and Meetings

1. EMC Europe Workshop will be held on June 14-15, 2007, in Paris, France.

2. The 7th International Symposium on Electromagnetic Compatibility and Electromagnetic Ecology will be held on June 26-29, 2007, in St. Petersberg. Russia.

3. 2007 IEEE International Symposium on Electromagnetic Compatibility will be held on July 8-13, 2007, in Honolulu, USA.

4. Asia Pacific Radio Science Conference (AP-RASC 2007) will be held on September 17-20, 2007, in Perth, Australia.

5. The 17th International Conference on Electromagnetic Disturbances will be held on September 19-21, 2007, in Bialystok, Poland.

6. The 18th Zurich Symposium on EMC will be held on September 24-28, 2007, in Munich, Germany.

2. Technical Trends

VHF Broadband Digital Interferometer for Lightning Imaging and Monitoring

Lightning Research Group of Osaka University (LRG-OU) has been developing VHF Broadband Digital Interferometer (DITF) to image precise lightning channels and monitor lightning activity widely. The feature of broadband DITF is its bandwidth (from 25MHz to 100MHz) and implicit redundancy for estimating VHF source location. Since the VHF broadband DITF own the superiority to image lightning channels with rather short base line, LRG-OU considers an application of BDITF to the space-borne measurement system. One of the possibilities to realize the idea is a Panel Extension Satellite (PETSAT). PETSAT may consist of some independent panels. Each panel will be designed to own individual function and the configuration of PETSAT is adjustable depending on the objectives. Since it is shown that the short baseline of DITF could accomplish the high time and space resolution for VHF source locations, one can reach an idea of VHF broadband DITF operation on PETSAT. PETSAT is planed to be a low altitude satellite about several hundred kilometers from the ground, and the locations accuracy of 0.01 radians may provide us the sufficient and unique opportunity to discriminate between the active thundercloud from non active ones by satellite observations. (Prof. Z. Kawasaki)

Equivalent Circuit of CMOS Output Buffer for Power Supply Noise Simulation

To realize high-speed noise simulation at board level, an output buffer model of a CMOS inverter circuit is simplified as an example for power-supply noise simulation by SPICE. When inverters are switching simultaneously, the power-supply noise is reproduced in good accuracy with an equivalent single inverter composed of a PMOS and an NMOS; each of them represents a group of FETs connected in parallel respectively, and the model parameters of each MOSFET are determined based on the physical dimensions of each transistor. When inverters are edge-controlled and operating in different timing, the power-supply noise can also be reproduced with an equivalent single inverter and input resistors that reflect the delay time of the input signals of the original circuit. The values of resistances are calculated based on the delay times of input signals. (Prof. O. Wada)

Conducted Noise Suppressor using ferrite Cores and Negative Impedance Converter

The principle of the proposed circuit of conducted-noise suppressor is explained. The influences of the resistances, which are required for DC stability, on the suppressing performance are shown. It was found that the resistances cause amplification of conducted noise. Miniaturizing the Negative Impedance Converter realized improvements of the suppressing performance. It was also shown that the combination of two kinds of ferrite cores broadens the suppressing range of frequencies. (Dr. A. Nishikawa)

Micro Gap Discharge Measurement

The voltage and current rise time due to small gap discharge as the low voltage ESD was investigated in time domain. The measurement system was improved on the band width from 6GHz to 12GHz using the coaxial electrode system. Also, the sensing system was changed from the coupled transmission lines to an E-field sensor and a H-field sensor. The insertion loss of the experimental system was within about -3dB in frequency range below 12GHz. It was confirmed that the distributed constant experimental system with coaxial electrode enables to measure the very fast transition duration of about 40 ps in 12GHz bandwidth. As a consequence of the experiment using the system, voltage and current rise time of transition duration were shown 35 ps or less. Besides, the rise times were changed in configuration of electrodes, source polarity and discharging voltage. (Dr. K. Kawamata)

High-Frequency–Carrier Type Magnetic Probe

Recently, magnetic near field measurements of electronic devices are indispensable to establish techniques of evaluating and suppressing an electromagnetic interference. In this paper, a high frequency carrier type magnetic field probe, which has high sensitivity and high resolution, called GMI (giant magneto-impedance) probe, is proposed. As characteristics of the GMI probe, input-output, frequency and shielding-effectiveness are quantified. And its validity of magnetic near field measurements is demonstrated by comparing with a conventional shielded loop coil probe and numerical modeling. The GMI probe can clearly detect current concentration at an edge of a microstrip line, which allows high resolution measurements. (Prof. H. Inoue)

Power Meter Calibration System for Millimeter

A calibration system of RF power sensors has been newly developed at the National Institute of Information and Communication Technology (NICT). It can calibrate RF power sensor with a 2.4 mm coaxial connector in the frequency up to 50 GHz at 1 mW, and also applicable for any types of connectors such as 3.5 mm, Type-N, 2.92 mm and 7 mm connectors using adaptors. In order to calibrate the sensor accurately, the Simultaneous Comparison and Substitution Method is employed as the algorism of calibration method. The newly developed system has a performance that the expanded uncertainty of the calibration of a power sensor with 2.4 mm connector is 3.5 % at 50 GHz (coverage factor k = 2). (Dr. Y. Yamanaka)

Investigation of LCL Characteristics for Power Line Communications

In Japan, power-line communication (PLC) is proposed only as an in-house system. One of concerned matters is leakage electromagnetic field from power lines. Common-mode currents, which are generated at discontinuities and unbalanced loads, are the most important factor generating the fields. LCL (Longitudinal Conversion Loss) is the parameter denoting the degree of unbalance. In this article, we discuss the characteristics of LCL at an input terminal of two-parallel line with unbalanced load circuit on a viewpoint of transmission-line theory. By applying the equivalent expression in common-mode and differential-mode terminals for outlet, the analysis is developed. As a result, we show that the variation of input LCL becomes large according as load LCLs are high. (Prof. Y. Kami)

Propagation of High-Permeability-Sheet Loaded Waveguide

Propagation properties of rectangular waveguide loaded by a high-permeability sheet are studied experimentally in cut-off range. The attenuation of the guide is enhanced when an anisotropic high-permeability sheet made of NIZn ferrite is loaded on its E-plane, which can be applied as a shielding manner of enclosure openings. When the magnetic sheets are applied to both H-plane of the guide, the propagation property is considered as TEM guide approximately. One of the possible applications of this structure is a guide for ε and μ measurements in VHF-UHF range. (Prof. K. Hatakeyama)