Technical Visit
of
Measurement Facilities
in
Laboratoire de RadioPropagation
et Electronique
Université des Sciences et Technologies de Lille
LRPE Bat. P3
59655 Villeneuve d'Ascq cedex
France
Contact:
Pr. Bernard Démoulin:
Tel : + 33 (0)3 20 43 48 56
Fax: + 33 (0)3 20 43 67 98
Pr. Pierre Degauque:
Tel : + 33 (0)3 20 43 48 49
Fax: + 33 (0)3 20 33 72 07
Bernard.Demoulin@univ-lille1.fr
Pierre.Degauque@univ-lille1.fr
Visit of the Laboratoire de RadioPropagation et Electronique LRPE
In connection with the COST’meeting a visit of the measurement facilities of the LRPE will
be organized. The visit is focused toward the activities of the laboratory in the domains of
EMC. Short conferences about the works performed by the LRPE in the field of numerical
simulations applied to solve EMC problems and examples of tests carried out in mode stirred
reverberation chamber, anechoic chamber and TEM cell are presented.
Program of the visit
S. Baranowski
Theoretical simulation of mode stirred reverberation chambers by means of optical
approaches
L. Koné, A. Lorthois
Behavior of small rectangular shaped cavities tested in mode stirred reverberation chambers
B. Démoulin, L. Koné
Transfer impedance measurements of shielded cables and connectors
R. Razafferson, P. Mariage
Measurements of Emission due to Power Line Communication Systems
J. Baudet, I. Abadi
Characterization of the Emission of Integrated Circuits and PCBs
The location of the visit will be at the ground of building P3 on the campus of Villeneuve
d’Ascq.
The name of the laboratory is changing, the new will be: TELICE (Laboratoire de
Télécommunications, Interférences et Compatibilité Electromagnétique)
Theoretical Simulation of Mode Stirred Reverberation Chambers
by means of Optical Approaches
S. Baranowski
Université des Sciences et Technologies de Lille
LRPE (TELICE)
Sylvie.Baranowski@univ-lille1.fr
Summary of the activities of LRPE (TELICE) in theoretical simulation of mode
stirred reverberation chamber (MSRC)
Theoretical simulation of the field distribution inside MSRC are today considered, in
order to improve the mode stirred methods and to characterize the electromagnetic
coupling phenomena introduced by the devices under test.
At high frequencies range, we can consider that the dimensions of the reverberation
chamber are large compared to the wavelength. In these conditions an optical
approach may be used to predict the field distribution in the room. Then, the
electromagnetic field at any point within the cavity may be considered as the sum of
the incident wave merging from the source antenna and the multiple reflections
occurring on the walls of the room. Paths and amplitude of the reflected waves are
equivalent to the radiation of N shifted images of the antenna source weighted by the
reflection parameters of the walls.
Due to the high conductivity of the walls, the reflection parameters are closed to one,
and then a too large number of images is required to reach a numerical convergence.
In order to solve this problem, different solutions are studied:
• statistical analysis of the field distribution
According to many authors, the field distribution provided by a perfect mode stirred
method is governed by the well known χ distribution; a similar distribution is also
observed for a lot of receiving points randomly spaced in the room and for short
variations of the carrier frequency of the source. Consequently, the number N of
images, required by the computation, are determined when the cumulative
distribution function of the field amplitude becomes stationary. The use of this
criterion may reduce seriously the consuming time of the computation.
Theses results are compared with others obtained with FDTD or finite element codes
developed by EADS.
• 2D approach
A less consuming time 2D approach can be useful to evaluate the method (in this
case, the cavity is modelized by a wave guide cross section, fed by a line of dipoles).
The considered number of images can then be very high (compared to a 3D
approach) and the convergence phenomenon can be studied.
The results are compared with others obtained in Supelec, with a 2D finite elements
approach (details can be found in the paper of M. Cauterman).
Behavior of Small Rectangular shaped Cavities tested in
Mode Stirred Reverberation Chamber
L. Kone, A. Lorthois
Université des Sciences et Technologies de Lille
LRPE (TELICE)
Lamine.Kone@univ-lille1.fr
Summary of the activities of LRPE (TELICE) in reverberation chambers
A reverberation chamber of sizes 2.5 m x 1.8 m x 2.8 m was installed in our
laboratory seven years ago. After a first exploration of this measuring tool the studies
were focused toward the characterization of the field distribution in the room and test
on various devices such cable assemblies and more recently on containers of
medium sizes.
Experiment field consists to compare the measurements carried out in mode stirrer
reverberation chamber with anechoic room under the condition of plane wave
illumination. These works are achieved with the cooperation of aircraft industry
especially with EMC group of the French research center of EADS company. To
avoid heavy experiments in reverberating room of large sizes EADS is developing a
specific numerical code devoted to the simulation of the MSRC field distribution.
Experiment presented in the visit deals with the test on small shielded enclosures.
Another study in this area concerns the statistical laws which may use to characterize
the field distribution features in reverberation room. This work relevant to a
cooperation with the Politecnico di Torino (Italy) and Techno Centre RENAULT
(France) is based on statistical tests and measurements carried out in rooms of
different sizes. Use of a transmission line model is considering in order to calibrate
the specified field amplitude in the room.
Third study on MSRC is working with the contribution of Supélec ( France). Aim is to
develop a two dimensional models (wave guide cross section) in order to acquire
amount of data about the distribution of the field versus a wave number scale. This
approach will be connected with the concept of random plane waves distribution and
to test the optical ray approaches. (contribution of S. Baranowski brings details on
this last topic).
Transfer Impedance Measurements of Shielded
Cables and Connectors
B. Démoulin, L. Koné
Université des Sciences et Technologies de Lille
LRPE (TELICE)
Bernard.Demoulin@univ-lille1.fr
Summary of the activities of LRPE (TELICE) in transfer impedance
measurements
Since 1973 the LRPE group acquired experience in the domain of transfer
impedance measurements. Firstly were developed a triaxial bench test and use of
transient current injection in order to determine the absolute value and phase angle
of leaky feeders’ Zt with low optical coverage braided shield.
Afterward, these studies were extended to the measurement of Zt at increase
frequencies up to few GHz. Special bench test proposed by our group in eighty nine
was developed In order to avoid phase delay due to the propagation phenomena.
Therefore the measurements are carried out on a small gap (10 cm) of the cable
shield. The outer disturbing current is generated by means of a short circuited
coaxial cavity of 70 cm long. Below 100 MHz the measurement is like the usual
triaxial method while above 100 MHz Zt is given at specific frequencies fitted with the
resonance of the cavity. This method is also applied to test the transfer impedance of
connectors.
Illustration of this method is proposed in the visit.
Other works about the characterization of the shielding effectiveness of cable
assemblies are also turned toward the transfer impedance concept applied to the
multi wires shielded cables. Theoretical simulations and measurements were aimed
to point out the effect of the expected inner eigen modes.
More recently these studies were extended to micro wave domain especially to
compare various measurements tools as TEM cell, GTEM cell, Wire injection
method*, INTEC cell**, LRPE cell*** and MSRC****. These studies were performed
under a financial support of the European Project SOBITS managed by Universiteit
Gent (Belgium).
* Wire injection method is found in IEC standard IEC 96-1
** INTEC cell is a small sizes bench test developed by the University of Gent and devoted to the
measurements on small connectors
*** LRPE cell is the bench test mentioned above
**** MSRC is the Mode Stirrer Reverberation Chamber as found in IEC standard( IEC 1726 draft)
Measurements of emission due to
Power Line Communications Systems
R.Razafferson, P.Mariage
Université des Sciences et Technologies de Lille
LRPE (TELICE)
Richard.raza@univ-lille1.fr
Summary of the activities of LRPE (TELICE) in anechoic chamber
Actual trend of telecommunication systems is to use the power lines as
electromagnetic guide in order to travel digital data on short distance as the indoor
power network. Some scientific works are achieving in order to determine the
maximum available power of high frequency signals injected on these lines and
specify the immunity level of the concerned circuits.
Early 2001 our laboratory started some studies about this subject under cooperation
with France Telecom R&D. Aim was to perform experiments and simulation to
understand the physical mechanisms involved trough the propagation, radiation and
induction phenomena of transmission lines with random parameters.
The experiment proposed in the visit deals with the measurements carried out on low voltage
power line tested inside the anechoic chamber installed in our laboratory. Size of the room
being 5.4 m x 5.17 m x 2.45 m a cable sample of four meters long may be tested without
connection on the local power network. Aim of the measurements is to determine the
magnetic field amplitude in the vicinity of the cable at distance from 20 cm up 1 meter. The
concerned frequency range goes from 1 MHz to 30 MHz. The collected measurements
correspond to the curves giving the variation of the magnetic field amplitude versus the
frequency under various configurations of the indoor line model test cable with random
arrangement of phase, neutral and ground wires. An Ideal transmission line like a bifilar with
parallel wires is also tested in order to compare the results with the predictive models based
on the uniform parameters transmission line theory.
Future developments of these studies will concern other experiments performed
inside a room equipped with a real power line network.
Characterization of the Emission of Integrated Circuits and PCBs
J. Baudet , I. Abadi
Université des Sciences et Technologies de Lille
LRPE (TELICE)
Jacques.Baudet@univ-lille1.fr
Summary of the activities of LRPE (TELICE) in electronic components and EMC
Studies relevant to electronic components and EMC were started by our group in
1988 in order to determine the sensitivities of various usual ICs technologies. These
works were performed under the cooperation with INRETS (French ministry of
transportation) to insure safety of automatic vehicles controlled by aboard electronic
equipment. These studies concerned the sensitivity estimation of digital circuits
against disturbances sent toward the input, output and supply ports of the
component.
Another project was connected with the disturbances applied at operational amplifier
ports. Sensitivity against destructive and non destructive disturbances was
concerned respectively. Physical interpretation of the spurious phenomena as off set
voltage or rectification due to non destructive incoming interference was achieved
with the help of specified test board and theoretical simulation taking into account the
contribution of expected inner parasitic parameters of the circuit.
More recently activities in this domain was turned toward the emission of the digital
circuits and immunity under combination of interference sources.
Study of the emission was performed in cooperation with ALCATEL Bell in
Antwerpen (Belgium). Aim was to link the radiation of the circuit with the
characteristics of the inner working signals. TEM cell was an attractive tool to collect
data about the radiation of the chip and its connected traces board.
Experiment presented in the visit deals with this topic.
Another work about EMC coupling and electronic component is leading under a
France-Morocco cooperation with the Ecole Supérieure de Technologie de Fès
(Morocco) on the effect of combination of disturbances occurring at the input of a
digital circuit. Especially are concerned the addition of the effect due to
electromagnetic cross talk coupling throughout the trace on board and induced
voltages (or current) by an external radio frequency source working above 100 MHz.
Under these conditions we show that external field controls the sensitivity toward the
cross talk coupling.