EMCJ99-101 (1999-12)
Power Decoupling
Circuit for Measurement of EMC Characteristics of IC/LSI
Osami WADA, Ryuji KOGA, and Yukihiro FUKUMOTO*
Faculty of
Engineering, Okayama University
*
Matsushita Electric Industrial Co., Ltd.
3-1-1
Tsushima-naka, Okayama
Abstract:
Basic concept and outline are described of measurement methods of EMC
characteristics of semiconductor devices, particularly on the magnetic probe
method proposed in SC47A/WG9 of IEC, and a power decoupling circuit is proposed
for reducing effects of impedance of power system outside EUT. The decoupling
circuit can also be used in measurement for modeling of power current of
IC/LSI. With the decoupling circuit, current flowing toward outside circuit is
simulated and it is reduced under -50dB.
Key words: IC/LSI,
EMC characteristics, power decoupling, magnetic probe method, modeling
EMCJ99-102 (1999-12)
Two-dimensional
Analysis for Power Distribution Planes in Multilayer Printed Circuit Boards
Takashi HARADA*, Kiyoshi ASAO**, Hideki SASAKI*,
and Yoshio KAMI***
*Device
Analysis Technology Laboratories, NEC Corporation
**Production
Systems Development Laboratories, NEC Corporation
***The
University of Electro-communications
*4-1-1
Miyazaki Miyamae-ku Kawasaki, Kanagawa 216-8555
**3-484 Tsukakoshi Saiwai-ku Kawasaki, Kanagawa 210-8511
***1-5-1
Choufugaoka Choufu-shi, Tokyo 182-8585
Abstract:
This report analyzes transmission and impedance characteristics of power
distribution planes in multilayer printed boards with SPICE. A two-dimensional
circuit model, which consists of capacitors, inductors, and resistors, is used
to analyze the characteristics. Accurate analysis can be achieved to
incorporate effect of circuit losses appropriately. The characteristics
involving decoupling capacitors can be analyzed by considering effects of
interconnect inductance. Voltage distributions in the planes are also analyzed.
It is shown that voltage magnitude depend on source point. The information on
the voltage distributions is effective to design power-distribution-decoupling
and PCB layout.
Key words:
EMC, EMI, Printed circuit board, Power/Ground , SPICE
EMCJ99-103 (1999-12)
A New Model
of LSI at Power Supply Terminal for EMI Simulation
Masashi OGAWA, Hiroshi WABUKA, and Hirokazu
TOHYA
EMC
Engineering Center, Device Analysis Technology Labs, NEC Corporation
1-1,
Miyazaki 4-Chome, Miyamae-ku, Kawasaki, Kanagawa 216-8555 JAPAN
Abstract:
A radio frequency (RF) current passing from power supply terminals into ground
terminals in a LSI on a printed circuit board (PCB) is one of the main factor
at electricmagnetic interface (EMI) from circuit system, then it is important
to simulate for EMI to use an appropriate model for LSI. In this report, a new
LSI model by simplifying all network data of internal LSI circuit is proposed,
which is composed of transistors and load capacitors, and the simulated values
of current spectra in the power supply line of a PCB using the proposed model
agreed well with the measured values.
Key words: LSI
model at power supply terminal, simulation, LSI internal capacitor
EMCJ99-104 (1999-12)
Power
Current Model of IC with Internal Impedance
Yasuo TAKAHATA, Atsushi WATANABE, Osami WADA,
Ryuji KOGA, and Yukihiro FUKUMOTO*
Faculty of
Engineering, Okayama University
*Matsushita
Electric Industrial Co., Ltd.
3-1-1,
Tsushima-naka, Okayama 700-8530
*1006
Kadoma, Kadoma City, Osaka 571-8501
Abstract:
The main cause of electromagnetic radiation from a digital PCB is high-speed
switching current flowing on power supply pins of IC/LSI. To estimate and to
reduce EMI, we need a behavior model to evaluate high frequency current at a
power supply terminal of an IC. In this report, the authors propose an
equivalent circuit model which is composed of an equivalent internal current
source and an equivalent internal impedance to express current penetrating an
IC from a power pin to ground. To verify the model, simulated results of
reduction of high frequency current when inserting a series inductor on a power
supply line is shown with correspondent results of measurement.
Key words:
EMI, IC/LSI, simulation, high frequency current, current source model, internal
impedance
EMCJ99-105 (1999-12)
Calculation
Models for a Magnetic Shielding Effectiveness Measuring Instrument
Tomoki Matsubara, Atsuhiro Nishikata* , Yasutaka Shimizu**,
and Yukio Yamanaka***
Graduate
school of Science and Engineering, Tokyo Institute of Technology
*CRADLE, Tokyo
Institute of Technology
**Graduate
school of Decision Science and Technology, Tokyo Institute of Technology
***Communications
Research Laboratory / MPT
2-12-1 O-okayama,
Meguro-ku, Tokyo 152-8552
Abstract:
The SE (Shielding Effectiveness) value of shielding material vary depending on
the evaluation method used. In this report, we propose four types of calculation
models for calculation of SE, obtained by one of popular measurement methods
(KEC method) of magnetic SE. The first model assumes a magnetic dipole source
and an infinitely-large plane shield, by which the measured SE is
well-predicted when the distance between the source point and the observation
point is assumed as 17mm. Second model (Schelkunoff's model), which is
one-dimensional and easy-to-calculate, is found to be well-applied when r=6mm
is assumed. The resistive sheet approximation for the shielding material is
introduced into both the previous model and the 3-dimensional FDTD model. The
validity of resistive sheet approximation is shown by comparison of calculated
SE with measured one, as well as the validity of each models.
Key words:
Magnetic Shielding Effectiveness Measuring Instrument, Electromagnetic
Shielding, Dipole source, Schelkunoff's formula, resistive sheet, 3D-FDTD
EMCJ99-106 (1999-12)
System
Response of the FET Input Static Voltmeter with a Rod Electrode
Nobuo MUROTA
Industrial
Research Institute, Aichi Prefectural Government
Hitotsugi-cho,
Nishishinwari, Kariya-shi, Aichi 448-0003 Japan
Abstract:
This study describes the characteristics of the tip on the probe that detects
the field potential. The figure of the probe tip is a small rod. This probe tip
is connected to the input of high impedance amplifier of the static voltmeter
for the potential measurement. The effect of the tip length is measured using a
circular electrode that is driven by pulse voltage to generate a known
potential field. The probe senses potential widely around its circumstances.
The measured voltage is saturated according to the probe tip length.
Key words: electrostatic
charge, charged voltage, probe, voltage distribution, capacitance
EMCJ99-107 (1999-12)
FDTD
Computation of Electromagnetic Interference Voltage Induced at an Implanted Pacemaker
due to Portable Telephones
Jianqing Wang and Osamu Fujiwara
Department
of Electrical and Computer Engineering, Nagoya Institute of Technology
Gokiso-cho,
Showa-ku, Nagoya 466-8555 Japan
Abstract:
A prediction of the electromagnetic interference (EMI) of pacemakers due to
portable telephones is significant in improving the immunity of pacemakers. The
Pacemaker Committee of Japan recently conducted immunity tests of pacemakers
for portable telephones, and consequently concluded that the connector between
the pacemaker housing and the lead wire of electrode plays a major role for the
EMI due to portable telephones. Based on this finding, a computer model for predicting
the EMI level has been presented, in which the internal impedance looked from
the connector and the metal portion consisting of the pacemaker housing and the
lead wire of electrode were considered as a load and two halves of a receiving
antenna, respectively. Interference voltages induced through the connector were
analyzed by using the finite-difference time-domain (FDTD) method in
conjunction with a torso and portable telephone model. The modeling was
validated by comparison with the previously reported experimental results.
Key words:
electromagnetic interference, implanted pacemaker, portable telephone, FDTD
analysis
EMCJ99-108 (1999-12)
Dependence
on Tissue Structure of Localized Peak SAR inside Head Model for 1.5GHz Microwave
Far-field Exposure
Takuji USHIMOTO, Jianqing WANG, and Osamu
FUJIWARA
Faculty of
Engineering, Nagoya Institute of Technology
Gokiso-cho,
Showa-ku, Nagoya 466-8555 Japan
Abstract:
We investigated the dependence on the head tissue structure of localized peak
SARs (specific absorption rate) inside our newly developed MRI (Magnetic
Resonance Imaging) based head model for far-field exposure in all irradiation
directions of the microwaves being employed for portable telephones. The FDTD
(Finite-Difference Time-Domain) method was used to compute the SARs inside the
MRI based head models consisting of various tissues up to 15 kinds for 1.5 GHz
microwave far-field exposure of 1 mW/cm2 specified in an
uncontrolled environment. As a result, we found that in the head model having
less than three kinds of tissue, the localized peak SAR reaches maximum for
side irradiation, decreasing with increasing the tissue kind, while in the head
model with more than four kinds of tissue, the localized peak SAR reaches
maximum for rear irradiation, whose value increases with the tissue kind and
reaches saturation point for over five tissues including skin, fat, muscle,
bone, and brain. The latter finding suggests that the head model having the
above five tissues at most can be used enough for dosimetry evaluation with
high accuracy.
Key words: Microwave
far-field exposure, dosimetry, FDTD analysis, MRI based head model,
tissue-structure dependence
EMCJ99-109 (1999-12)
Study of
Electromagnetic Scattering by Buildings in Digital TV Broadcasting Using
Partial Conformal Mapping Method
Yasumitsu Miyazaki
Department
of Information and Computer Sciences, Faculty of Engineering, Toyohashi
University of Technology
Hibarigaoka
1-1, Tempaku-cho, Toyohashi, 441-8580 Japan
Abstract:
Recently, instead of analog TV broadcasting, digital TV broadcasting are used
as satellite broadcasting and surface broadcasting. In analog TV broadcasting,
electromagnetic compatibility problems such as electromagnetic interference and
ghost problems due to natural geographical environment and high buildings are
severe problems to be solved. Signal processing for electromagnetic
compatibility problems are also required for strong interference cases even in
digital TV broadcasting, although weak interference problems are well processed
in case of digital TV broadcastings. In this paper, using partial conformal
mapping method, electromagnetic scattering is investigated for interference
problems due to high buildings and natural geo-effects.
Key words:
digital TV broadcasting / electromagnetic scattering / conformal mapping /
electromagnetic compatibility
EMCJ99-110 (1999-12)
Analysis of
Electromagnetic Interference Characteristics of Wireless LAN in Buildings by
FDTD Method
Koichi Takahashi, Tadahiro Masuda, and Yasumitsu
Miyazaki
Department
of Information and Computer Sciences, Faculty of Engineering, Toyohashi
University of Technology
Hibarigaoka
1-1, Tempaku-cho, Toyohashi, 441-8580 Japan
Abstract:
The radio communication systems such as cellular phones and wireless LAN
systems have been developed rapidly in the recent years, and accordingly the
interference and operational error of electronic systems become serious
problems. Therefore, understanding of propagation characteristics of radio
communication waves is necessary to develop high performance and reliable
communication systems. Ray-tracing method is mainly applied for the analysis of
indoor propagation channels. However, for the analysis of complex propagation
channels, ray-tracing approach needs complex formulation and very long
calculation times. In this paper, FDTD method is applied to show the
interference characteristics of radio systems, such as wireless LAN, mobile
communication in various structures. The locations inside the buildings, which
receive week intensity of electric field are investigated.
Key words:
wireless LAN / cellular phone / FDTD method / electromagnetic interference
EMCJ99-111 (1999-12)
Electromagnetic
Interference Characteristics by Group of Buildings in High-Speed Mobile Communication
Systems
Paul Selormey and Yasumitsu Miyazaki
Department
of Information and Computer Sciences, Faculty of Engineering, Toyohashi
University of Technology
Hibarigaoka
1-1, Tempaku-cho, Toyohashi, 441-8580 Japan
Abstract:
Detailed characterization of radio propagation channel is a major requirement
for successful design of mobile communication systems. In this paper, mobile
radio channel characterization process based on 2D FDTD method is presented.
The merits and demerits of the currently used methods, namely impulse-response
method and ray-tracing methods are briefly discussed. Various simulation models
consisting of streets with buildings are examined. Wave propagation patterns in
the whole channel and the received signals at some line of sight and out of
sight locations are presented . The results show that the effects of the number
of buildings, not directly surrounding a receiving location, on the received
signal is not significant.
Key words:
FDTD method / propagation characteristics / wave scattering / mobile radio
waves
EMCJ99-112 (1999-12)
Indefiniteness
in EMI Methods for In-situ Measurement for Industrial, Scientific and Medical
(ISM) Equipment
-Making
Clear the Technical Inconsistency Found in In-situ Measurement by CISPR 11 Recommendations-
Shigekazu Shibuya*,
Hideya Andou**, Kazuaki Yoshimura**, Haruo Ishizuka*, Toshio Kinoshita***, Akinori Kameshima*, Takashi Suzuki#, Naoki Suzuki##, Yutaka Ohno@, Kunio Takamura, Kouichi Yamaguchi, and Juichi Kaku@@
**Touin
Yokohama University
*Shibuya,.
Ishizuka or Kameshima Consultant office
***EMCT EMC
Study Group
#Net Alpha
##Wooden
Bell Consultant
@Systemtechnico
@@Colory
Abstract:
CISPR 11 (1997) recommends definitely the methods of in-situ measurement
(called "in-situ measuring
method") to cope with interference radiated from large scale ISM equipment.
It calls for measuring the field strength at 2m high above the ground and 30 ~ 100m
far from the exterior wall of the building in which the equipment is installed,
however, it invites a confusion in the field because the test results show a
large difference depending on chosen directions. This paper indicates that the
basic cause is .in the indefiniteness of the measure and explains its
countermeasure.
Key words:
EMC, ISM equipment, in-situ measurement, indefinite scale, freespace, U-site
EMCJ99-113 (2000-01)
Experimental
Conditions to Calibrate Induced-Current Meters for a Human Body Standing on the
Ground Plane and Exposed to RF Fields
Yuya Nakamoto,
Soichi Watanabe*, Yukio Yamanaka*, and Masaharu Takahashi
Musashi
Institute of Technology
*Communications
Research Laboratory, M.P.T
1-28-1 Tamazutsumi,
Setagaya-ku, Tokyo 158-8557 Japan
Abstract:
Experimental conditions to calibrate induced-current meters for a human body
standing on the ground plane and exposed to RF fields are investigated in this
report. A resonant mono-pole as a radiation source and another mono-pole as a
human body on the ground plane in an anechoic chamber are assumed. The induced
current on the receive antenna is calculated with method of moment (NEC-2).
Key words:
foot current, induced current, SAR, calibration, method of moment anechoic
EMCJ99-114 (2000-01)
Measuring
Method for Digital IC Terminal Output in the High-frequency Range above 1GHz
Satoshi Kazama,
Shinichi Shinohara, and Risaburo Sato
Electromagnetic
Compatibility Research Laboratories Co., Ltd.
6-6-3
Minamiyoshinari, Aoba-ku, Sendai-shi 989-3204
Abstract:
This paper describes a new technique for evaluating methods of measuring the
terminal output of a digital IC. The measured output data is used for
evaluating electromagnetic interference (EMI). This technique uses frequency
characteristics of the circuit network that is inserted between the digital
IC's terminal and the measuring instrument. The characteristics are measured
accurately by using a network analyzer at high frequencies. We use this
technique to evaluate methods of measuring EMI from digital ICs in the
high-frequency range above 1 GHz. These results may improve the systems for
measuring the output from an IC terminal.
Key words:
Digital IC, Current on terminal, EMI, Measuring method, Evaluation method
EMCJ99-115 (2000-01)
A Method
for Estimating the Shielding Effectiveness of Holes on a Small-Size Shield
Enclosure
Tsuyoshi Yamato,
Fumishiro Tsuda, Shinichi Shinohara, and Risaburo Sato
Electromagnetic
Compatibility Research Laboratories Co., Ltd.
6-6-3 Minami-Yoshinari,
Aoba-ku , Sendai 989-3204 Japan
Abstract:
The electronic field strength in the far field and the intensity of magnetic
the field in the near field were measured assuming an application to compact
information technology equipment that has recently become widespread and by
using a small-sized shield case. In the structure of distributions of the
intensity of the magnetic field in the near field, we found that the shielding
effectiveness in the far field was determined by the maximum radiation level of
the intensity of the magnetic field in the near field from a single hole. We
also found that the shielding effectiveness in the far field was related to the
intensity of the magnetic field in the near field. Therefore, we estimated the
shielding effectiveness in the far field by measuring the radiant intensity of
the magnetic field from a single hole.
Key words: shield
case, shielding effectiveness , far field , near field
EMCJ99-116 (2000-01)
Prediction
of Effect of Noise Suppression Device on Radiated Interference Suppression from
Printed Wire
Hidetoshi Yamamoto,
Shinichi Shinohara, and Risaburo Sato
Electromagnetic
Compatibility Research Laboratories Co., Ltd.
6-6-3, Minami-yoshinari,
Aobaku, Sendai 989-3204 Japan
Abstract:
In this paper, the suppression effect of noise suppression device on radiated
interference suppression from printed wire was discussed. The effect was calculated
from transmission theory and results shows good agreement with measured value.
Key words:
Electromagnetic interference, Radiated emission, Printed wire, Noise
suppression device, Suppression effect
EMCJ99-117 (2000-01)
Electromagnetic
Compatibility of Programmable Controllers with High Magnetic Field Environment
M. Hidaka,
R. Nagasawa, F. Naitou, S. Shimamoto (Tohoku Univ.), and Y. Murano (Kandenko Co., Ltd.)
Graduate
School of Engineering, Tohoku University
05
Aoba-yama, Aoba-ku, Sendai 980-8579
Abstract:
As the superconducting magnetic facilities are widely used, electromagnetic
interference due to the leakage magnetic field from the superconducting
facility have been gradually increased. This paper describes about the
electromagnetic compatibility test results of the programmable controller (PC)
in high magnetic field up to 2kG. The PC units , which include transformers
having magnetic core, are apt to be highly affected by the leakage magnetic
field. Therefore, characteristic of transformers magnetized by the external DC
field is described. And the magnetic shielding capability of ferromagnetic
plate are also discussed in this paper.
Key words:
Electromagnetic Compatibility, Programmable Controllers, Leakage Magnetic
Field, Magnetic Shielding
EMCJ99-118 (2000-01)
The Effect
of a Finite Ground Plane on the S-parameter between Two Dipole Elements
Katsumi Fujii
and Takashi Iwasaki
Department
of Electronic Engineering, The University of Electro-communications
1-5-1
Chofugaoka, Chofu, Tokyo 182-8585 Japan
Abstract:
The S-parameter between two dipole antenna elements on a finite ground plane is
measured in horizontal polarization using a network analyzer with TRL
calibration technique. The S21 is also calculated using the hybrid
method combined the method of moment (MoM) with the geometrical theory of
diffraction (GTD) and using the MoM in which the finite ground plane is divided
to planar-segments. The results show that the S-parameter can not be evaluated
by the hybrid method but can be evaluated by the MoM. It makes clear that the
antenna element direction of a rectangular ground plane should be wider when a
large ground plane can not be used.
Key words: S-parameter,
Finite ground plane, MoM, GTD, TRL calibration
EMCJ99-119 (2000-01)
Measurement
of Normalized Site Attenuation using Biconi-log Antennas
Atsuo Senga
and Takashi Iwasaki
Department
of Electronic Engineering, The University of Electro-communications
1-5-1
Chofugaoka, Chofu, Tokyo 182-8585 Japan
Abstract:
Normalized site attenuation (NSA) obtained with a pair of biconi-log antennas is
theoretically investigate using the moment method. It is found that the
radiation patterns, the positions of active antenna elements and the height
dependence of antenna factor have influence on the difference in NSA between measurement
values with biconi-log antennas and the specified values in CISPR 16.
Key words:
Biconi-log antennas, Site attenuation, Moment method, Antenna factor
EMCJ99-120 (2000-01)
Lightning
Protection for Information-oriented and Computerized Society
- Present State
and Future Project -
Sigeru Yokoyama
Komae
Research Laboratory, Central Research Institute of Electric Power Industry
2-11-1,
Iwado Kita, Komae-shi, Tokyo 201-8511 JAPAN
Abstract:
Outages due to lightning strokes has been increasing in electronic circuits,
computers and telecommunication systems inside a building.
We
show a few examples of lightning outages concerning such a facilities.
Moreover, we summarize overseas regulations related to lightning protection
measures of electronic circuits in a building and indicate problems when
applied to Japanese conditions. Finally we propose several projects which are
very important for better protection measures against lightning hazards to
electronic circuits and computer networks.
Key words:
lightning, lightning protection, highly information-oriented society, low
voltage distribution line, electric appliance, computer
EMCJ99-121 (2000-01)
A Pole-type
Distribution Transformer Model for Electromagnetic Transient Studies
Taku Noda,
Hiroshi Nakamoto*, and Shigeru Yokoyama
CRIEPI
* Kyushu
Electric Power Co.
2-11-1
Iwado-kita, Komae-shi, Tokyo 201-8511
*2-1-82
Watanabe-dori, Chuo-ku, Fukuoka-shi 810-8720
Abstract:
This paper proposes a transient simulation model of pole-type distribution
transformers for electromagnetic transient studies. The proposed model takes
into account the following effects : (1) capacitance between windings and an
enclosure and also between primary and secondary windings, (2) skin effects of
winding conductors and an iron core, and (3) multiple resonance due to the
combination of winding inductance and turn-to-turn capacitance. Thus, the model
accurately reproduces the frequency characteristics of a pole-type distribution
transformer in a wide range of frequency. The parameters of the model can
easily be determined by frequency-characteristic measurements using an
impedance analyzer. Because of the above capability, the proposed model enables
the accurate evaluation of over-voltages on distribution lines including
consumer-side over-voltages. In this paper, a 10-kVA pole-type distribution
transformer is modeled, and the proposed model is validated by comparisons
between simulated and laboratory-test results.
Key words:
pole-type distribution transformer, transient studies, EMTP, consumer-side over-voltages
EMCJ99-122 (2000-01)
Environmental
Magnetic Field in Office Building and Development of Magnetic Shieldings for
CRT
Kiyotomi Miyajima,
Kenichi Yamazaki, and Seietsu Tomita
Central
Research Institute of Electric Power Industry
2-11-1,
Iwado Kita, Komae-shi, Tokyo 201-8511 JAPAN
Abstract:
Personal computer monitors and televisions with cathode ray tube (CRT) may have
jitters in the alternating magnetic field. We measured magnetic fields in the
office building that had jitters problems.
In
this report, a diurnal variation and distribution of the magnetic fields that
have harmonics are showed. The occurrence mechanism of harmonics is explained.
And, a new mitigation method of jitters by the compensation magnetic field is
presented.
Key words:
CRT, jitters, alternating magnetic field, magnetic shielding
EMCJ99-123 (2000-01)
Analysis of
Electromagnetic Fields in the External Auditory Canal for Portable Telephones
with a Helical Antenna
Jianqing Wang
and Osamu Fujiwara
Department
of Electrical and Computer Engineering, Nagoya Institute of Technology
Gokiso-cho,
Showa-ku, Nagoya 466-8555 Japan
Abstract:
A half-wave dipole antenna trends towards being adopted for the immunity test
of medical devices for portable telephones from the viewpoint of operation
efficiency. In this paper assuming the immunity test of hearing aids, we
analyzed the electromagnetic fields in the external auditory canal for a
portable telephone with a helical antenna using the finite-difference
time-domain (FDTD) method, and compared the results with that for a half-wave
dipole exposure. The helical antenna was modeled as a stack of dipoles and
loops with an adequate relative weight according to Lazzi and Gandhi's
proposal. The head model was developed from magnetic resonance imaging (MRI)
data of a Japanese adult head. As a result, it was found both for the helical
antenna and half-wave dipole that the electric field shows a standing-wave
characteristic in the external auditory canal, while the magnetic field
decreases gradually with deepening into the external auditory canal. The
electric field around the entrance of' auditory canal for the helical antenna
is stronger than that for the half-wave dipole, and vice-versa in the middle
auditory canal. The magnetic field in the external auditory canal for the
half-wave dipole is generally higher than that for the helical antenna.
Key words:
portable telephone, immunity test, hearing aid, external auditory canal, FDTD
analysis
EMCJ99-124 (2000-01)
Development
of Electromagnetic Environment Design System for Private Wireless Communication
System
Yuji MAEDA and Kazuhiro TAKAYA
NTT
Lifestyle and Environmental Technology Laboratories
3-9-11
Midori-Cho, Musashino-Shi, Tokyo 180-8585 Japan
Abstract:
Recently, several kinds of wireless communication systems such as 2.4-GHz-band
wireless LANs and cordless phone are used in building and communication
troubles due to electromagnetic interference are also increased. This report
describes the electromagnetic environment design system, which was developed to
design ideal electromagnetic environments where communication troubles were not
occurred, for 2.4-GHz-band wireless LAN and cordless phone. This system
simulates the electromagnetic interference and effect of building materials for
electromagnetic propagation. It can provide an ideal arrangement of center
stations of wireless systems and an ideal indoor or outdoor environment where
wireless system are installed by estimating propagation characteristics and
communication characteristics. The system configurations and two examples of
actual design by using our system are introduced.
Key words:
Electromagnetic environment, Private wireless system, Propagation, Ray tracing,
Communication characteristics
EMCJ99-125 (2000-01)
A
Theoretical Study on Analysis of TV Ghost Caused by the Super Highrise Tower
and the Suppression of Reflected Wave Using the Wave Absorber
Takahiro Aoyagi,
Yasutaka Shimizu, Toshio Saito*, and Kenichi Harakawa*
CRADLE,
Tokyo Institute of Technology
*Research
& Development Department, Takenaka Corporation
2-12-1 O-okayama,
Meguro-ku, Tokyo 152-8552
*1-5-1
Ohtsuka, Inzai, Chiba 270-1395
Abstract:
In this report, TV ghosts caused by the super highrise tower are theoretically
analyzed at the viewpoint of DU ratio. The scattering wave from three type of
the super high tower are calculated with taking account of distances between
the transmission point, receive points and the tower. The effectiveness of the
electromagnetic wave absorber is also considered when the absorber is put on
the surface of the tower. As results in this report, the absorber of -10 dB
reflection coefficient is enough characteristics for cylindrical model to
vanish the TV ghost problem caused by the reflected wave. For X-shaped model
and the eight column model, the absorber which has -15 dB characteristics is
satisfying.
Key words:
EMC, GMT, wave absorber, super highrise tower, TV ghost, scattering wave
EMCJ99-126 (2000-01)
Permittivity
Measurement of Construction Materials in the Open Air
---
Numerical Analysis of the Measurement Accuracy ---
Shigemitsu Kaneko,
Masatoshi Kubota, Michio Miyakawa*, Nozomu Ishii*, Yasushi Kanai**, and Tatsuhiko Saeki*
Graduate
School of Science and Tech., Niigata Univ.
*Faculty of
Eng., Niigata Univ.
**Faculty
of Eng., Niigata Ins. of Tech.
Igarashi
2-8050, Niigata 950-2181 Japan
Department
of Biocybernetics, Faculty of Eng., Niigata Univ.
Abstract:
Effective use of electromagnetic waves (EM waves) in living spaces is realized
by controlling the transmission characteristics of EM waves into the spaces.
This can be done by choosing adequate construction materials and combining them
as to have the desired transmission characteristics.
To
establish the design methodology, one must know the permittivity of
construction materials. In this study, distribution of the standing wave is
computed based on FD-TD method. From the observed distribution, complex
permittivity of the construction materials has been estimated. The accuracy depends
on the permittivity, thickness of the material and so on, but the error was
smaller than approximately 1 %.
Key words:
Construction materials / Electric property / Standing wave method / FD-TD
method / Simulation
EMCJ99-127 (2000-01)
Shielding Effectiveness
through Multilayered Materials with an Arbitrarily Located Electric Dipole
Yoshiyuki YOSHIMURA, Isamu NAGANO*, Hiroaki
YOKOMOTO*, Toshio OOURA, and Satoshi YAGITANI*
Department
of Machinery / Electronics, Industrial Research Institute of Ishikawa
*
Department of Electrical and Computer Engineering, Kanazawa University
Ro-1,
Tomizu-machi, Kanazawa 920-0223 JAPAN
*2-40-20
Kodatsuno, Kanazawa 920-8667 JAPAN
Abstract:
We develop a method to evaluate the electromagnetic shielding effectiveness of a
multilayered materials placed nearby an electric dipole source. The shielding
effects are obtained in terms of a Sommerfeld integral, in which a spherical
wave radiated from the dipole is expanded into a large number of cylindrical
waves.
The
dipole source can be placed at any points with its axis either perpendicular or
parallel to the material. In the far-field (high-frequency) limit the numerical
results are in good agreement with a simple plane wave approximation, thus
validating the present method. An air gap between the material layers is found
to greatly improve its shielding effectiveness.
Key words:
shielding effectiveness, dipole, multilayered materials, Sommerfeld integral
EMCJ99-128 (2000-01)
Transparent
Thin Electromagnetic Wave Absorber for VHF Waves Composed of Divided Conductive
Films
Toshio TSUNO
Department
of Electrical Engineering, Toyama National College of Technology
13
Hongo-machi, Toyama-shi, Toyama-ken 939-8630 Japan
Abstract:
Nearly one meter in thickness of the air is required to absorb VHF
electromagnetic waves by using of a l/4 l
type wave absorber (resistance-film /air /reflecting-film). Inserting the
divided conductive films into the air layer, the thickness of the layer is
reduced because of the huge real effective dielectric constant of the devided
films. The effective dielectric constant with Coulomb interaction between
stripe-like devided conductive films is calculated, and used to estimate the
characteristics of the absorber. The panel of 10 cm in thickness can absorb
waves of about 100MHz. The characteristics are mainly controlled by the width
of the devided films and the air thickness between the devided films and the
reflecting film, but little by the incident angle.
Key words:
Electromagnetic wave absorber, VHF, Radio interference, Devided conductive
film, Transparent conductive film, Window pane
EMCJ99-129 (2000-01)
Experimental
Study on Manufacturing Magnetic Wood using Electromagnetic Wave Absorber in GHz
Band
Koichi Narita
and Hideo Oka
Graduate
School of Electronic and Electronical Engineering, Iwate University
3-4-5,
Ueda, Morioka 020-8551 Japan
Abstract :
The purpose of this article is to examine the possibility of using magnetic
wood as a woody electromagnetic absorber in GHz band. The results from measuring
4 types of different magnetic wood show that sandwich-type magnetic wood had
good electromagnetic wave absorbing characteristics. This article covers
experimental electromagnetic wave absorbing characteristics for sandwich-type
magnetic wood under different parameters. The results showed that the 20mm
thickness sandwich-type magnetic wood which was made with 40vol% mixture of
Ni-Zn ferrite 400L with particle diameter of 600 mm
over and 4mm layer of magnetics, could be used as a woody electromagnetic wave
absorber under 1.93GHz.
Key words:
electromagnetic wave absorber, magnetic wood, EMC, GHz band, magnetic powder,
composite material