| EMCABS EMC Abstracts |
EMCABS: 01-2-2003 FULL-WAVE MODELING OF VIA HOLES AND EQUIVALENT CIRCUIT EXTRACTION
FOR SIGNAL INTEGRITY ANALYSIS Abstract: A Finite Integration Technique based method
is used for estimating the equivalent circuit of a single via
hole in a multi-layer board. The via is partitioned in elementary
structures, and the scattering parameters are numerically evaluated
for each elementary structure. This approach is validated by comparison
with other calculated or measured results. Then, an equivalent
circuit is extracted for each partition and the cascade of them
gives rise to the final equivalent network. The influence of some
geometric parameters of a realistic via on its equivalent circuit
elements and its electrical performance is investigated. EMCABS: 02-2-2003 ELECTROMAGNETIC COMPATIBILITY OF A SYSTEM UNDER THE INFLUENCE
OF A BLUETOOTH TRANSMITTER Abstract: Bluetooth wireless technology is a new and innovative
specification, especially suited to replace expensive and restricting
conventional cabling. It is predicted that radio communication
based on this standard will gain significant importance in modern
communication. Bluetooth-Transmitters therefore will be found
close-by other electrical systems. The failure-free operation
and interaction of these systems must be ensured. In this paper
the coupling of Bluetooth transmitters into electrical systems
is examined. Measurements with a commercial Bluetooth-System are
performed and simulation according to the transmission line theory
and the method of moments are calculated. Both measurement and
simulation are made for the homogenous far-field and the inhomogeneous
field near the transmitting antenna. EMCABS: 03-2-2003 IMMUNITY ANALYSIS OF GENEC USING AN INTERMEDIATE LEVEL CIRCUIT
MODEL Abstract: Intermediate level circuit models are a very
fast and frequently accurate way of modeling the electromagnetic
coupling to enclosures. The technique has been extended to enclosures
with a circular-cross section and a small aperture coupling model
has been developed, based on aperture polarisability theory. The
model is validated using measurements on a simplified version
of the generic missile (GENEC), demonstrating that circuit models
can reproduce most of the features seen in the measured couplings
at frequencies up to 3 GHz. The models run in time scales of the
order of seconds/minutes compared to the days/weeks required by
full-wave solvers. EMCABS: 04-2-2003 EMC ANALYSIS OF POWER SUPPLY SYSTEMS OF MULTILAYER PRINTED CIRCUIT
BOARDS Abstract: EMC problems on Printed Circuit Boards (PCBs)
are frequently caused by the DC power supply system. Power planes
show resonances at higher frequencies, and decoupling capacitors
are often useless due to their highly inductive connections to
the power planes. These effects increase the power bus impedance.
Switching currents of the active devices causes a significant
voltage drop across this impedance. This voltage drop is not only
a source of radiated emissions, but can also cause potential signal
integrity (SI) problems. This paper examines the behavior of the
PCB level DC power bus and presents a fast and deeply integrated
approach to analyze power supply systems directly within the PCB
design process. EMCABS: 05-2-2003 DM-CM COUPLING AND RADIATION OF A 3-LAYER PCB ON TOP OF A METAL
CABINET PLANE Abstract: Metal cabinets form common mode (CM) circuits
with the printed circuit boards (PCB) inside. Those CM circuits
can affect the differential mode (DM) signal transmission and
cause high radiated emissions from the PCB. In this paper we study
the effects of the nearby metal cabinet plane on the transmission
characteristics and radiation of a 3-layer printed circuit board
with a ground plane. The structure has several resonances in 0.1
- 1.8 GHz frequency range. The good agreement between experimental
and simulation results is observed. EMCABS: 06-2-2003 ELIMINATION OF UNINTENDED REFLECTION WAVES FOR EMI ANTENNA CALIBRATION
USING THE MUSIC ALGORITHM Abstract: The EMI antenna is calibrated at open area test
sites or in anechoic chambers. Unintended reflection waves from
the test sites cause uncertainty in the antenna calibration. The
MUSIC algorithm was used to estimate and eliminate the unintended
reflection waves. The free-space antenna gain was determined by
using the three-antenna method from the intended wave obtained
applying the MUSIC algorithm. Good agreement is shown between
the gain obtained using the MUSIC algorithm and the free-space
antenna gain. EMCABS: 07-2-2003 NEW RADIOWAVE ABSORBERS USING MAGNETIC LOSS CAUSED BY METAL PARTICLES'
INTERNAL EDDY CURRENT Abstract: A new type of radio-wave absorber is proposed
which utilizes the eddy current loss of conductor particles appearing
as magnetic loss of the composite material. Theoretical investigation
based on a simple model suggests that the eddy current loss appears
as a broad peak of m"r, and the peak frequency can easily
be controlled by changing the particle size. A preliminary experiment
with metal composite materials showed the existence of the predicted
magnetic lossy characteristics due to the eddy current in particles.
The realizability of the wave absorber by manufactured composite
material is also shown. EMCABS: 08-2-2003 TIME DEPENDENCE OF TISSUE-EQUIVALENT DIELECTRIC LIQUID MATERIALS
AND ITS EFFECT ON SAR Abstract: Standard methods for measurement of the specific
absorption rate (SAR), including recipes for tissue-equivalent
dielectric liquids, have recently been the subject of discussions
among international standard organizations in the context of the
evaluation of mobile telecommunications equipment. Actual and
draft standards currently recommend glycol-type liquids as tissue-equivalent
liquids for frequencies above 1 GHz. Although the relative amounts
of the ingredients are specified in the recipes provided, possible
difficulties (relating to the stability of dielectric properties,
for example) are not clearly described. In this study we measured
the time dependence of the relative permittivities and conductivities
of glycol-based dielectric liquids, and evaluated their effects
on SAR. The experimental results suggest that relative permittivities
decrease with time and that conductivities remain nearly constant.
SAR, however, was not affected significantly by the change in
dielectric properties. EMCABS: 09-2-2003 EFFICIENT CALCULATION OF THE SHIELDING EFFECTIVENESS OF EQUIPMENT
CABINETS IN FULL-FIELD NUMERICAL MODELS Abstract: The paper describes an efficient algorithm for
the calculation of the shielding effectiveness (SE) of equipment
cabinets with perforated screens. The approach is based on the
description of the reflection and transmission properties of perforated
screens in terms of digital filter algorithms. These in turn are
embedded into numerical time-domain solvers allowing the prediction
of the SE of complex systems over a wide band of frequencies in
a single simulation. Results from this model compare well with
measurements and are obtained with modest computational costs. EMCABS: 10-2-2003 MODELLING OF GASKET MEASUREMENTS IN A H-T CELL Abstract: An equivalent model is set-up for a gasket,
when measured in a H-t cell. Starting point is the equivalent
circuit of the empty cell, which mainly consists of two coupled
inductances and some additional parasitic elements. To this we
add the influence of the empty gasket holder, which only introduces
a lower magnetic coupling. The gasket is represented in the circuit
by an impedance in parallel with the mutual inductance of the
holder. It contains both a low- and high-frequency part. The parameter
values are determined by matching with S-parameter values, measured
with a network analyzer. A large frequency range up to 600 MHz
can be covered with this model, which only contains a few, simple
elements. EMCABS: 11-2-2003 DESIGN AND REALIZATION OF AN IN VITRO EXPOSURE SYSTEM BASED ON
A RESONANT STRUCTURE OPERATING AT 1.8 AND 2.2 GHz EMCABS: 12-2-2003 PARAMETRIC ANALYSIS OF VERTICAL RISERS EFFECTS IN RANDOMLY EXTERNALLY-EXCITED
TRANSMISSION LINES Abstract: In this work, transmission line (TL) terminations
are modeled as the series connection of vertical TLs (risers)
with lumped impedances attached to ground. Effects of the vertical
risers on the terminal currents induced by external electromagnetic
interference (EMI) are investigated. A low-frequency lumped-parameter
model is developed that extends the conventional TL model. By
modeling EMI in terms of random plane waves, the proposed model
is then used to derive a statistical characterization of the effects
related to field-coupling with the vertical risers. The statistics
of the current magnitude induced in one of the line loads are
also derived in closed-form, as a function of the line aspect-ratio. |
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