Begining in 1998, workshops dedicated to a special field were incorporated to the programme of the MIDEM Conferences. During the workshop, five to seven invited speakers present papers on the chosen topics from different aspects within their special field, thus offering the audience valuable information. Time for thorough discussions is provided between invited presentations. Conference attendees are encouraged to present their research results in the Conference session dealing with the dedicated topic. Attendance at the workshop is included in the Conference registration fee.

For the year 2004, we are pleased to announce a

This year the workshop is focused upon the ways and means of protection against the various non-ionizing electromagnetic field (EMF) disturbances which not only may adversely affect the performance but may equally well detrimentally influence the normal operating conditions of the electronic devices and electric equipments as practiced in such areas as for instance telecommunications, information technologies, power generation and power transmission and the like. The discussion will be, by and large, centered upon the features such as electromagnetic compatibility (EMC), overvoltage protection (the protection of circuitry against the over voltage conditions resulting in damage or degradation of circuits performance - metal-oxide varistors, spark gap devices and other semiconductor protection elements), protection against the electrostatic discharge effects (the reduction of the effects of current and voltage spikes and transients by combination of resistors and voltage-sensitive semiconductor elements as well as by the use of spark gap devices), and the power-system protection, where the protective relaying for both the power lines and power equipment must satisfy the three stringent fundamental requirements: sensitivity, selectivity, and the speed of its response. (+ return to normal state).

It is a fact of life that the general public is nowadays perpetually exposed to wide variety of the non-ionizing electromagnetic fields as present in the environment. The EMF are characterized by different EMF amplitudes as well as by the extremely large spread of frequencies ranging from static and almost quasi-static fields (power transmission), high (medical applications, broadcasting industries) to the very highest frequencies as for instance used in modern mobile telecommunication systems and military applications. Consequently, the mankind is increasingly beset by the question of the possible harmful effects the EMF may exert on various biological systems and consequently on humans. In mostly the tutorial part of the workshop in conjunction to the previously described topics above, the related question of the effect of the non-ionizing EMF on the biological systems will be addressed, the current understanding of its possible health risk effects to the public will be discussed and the international guidelines for limiting exposure from EMF sources will be presented.

The workshop is jointly organized by MIDEM-Society for Microelectronics, Electronic Components and Materials, Ljubljana, Slovenia and University of Maribor, Faculty of Civil Engineering, Chair of Applied Physics, Maribor, Slovenia.

The programme committee is pleased to announce the following invited speakers, who will do their presentations on the following subjects.

Gregor Kovac,
SIQ Ljubljana, Slovenia

Basic EMC phenomena and worldwide EMC regulation for future VLSI Solutions

Electromagnetic compatibility (EMC) became one of the most important technical characteristics of new electronic devices for free access on global markets. The article describes:

Vladimir Murko, Andrej Pirih,
Iskra Zascite d.o.o., LJubljana, Slovenia

The new modern, integrated approach to effective external and internal overvoltage protection

The overvoltage protection represents the whole systematic approach: understanding atmospheric discharges and the origin of lightning, the way of catching the strike and take it to the ground and during that time how to protect devices against their influence. For simulation lightning strike, in the laboratory, two basic transient wave shapes of current impulses are used : 10/350 µs and 8/20 µs. These waves are also used as criteria for current absorption by overvoltage protective elements.

This paper deals with so called 6 level protection plan, which covers systematically and efficiently all effects of atmospheric discharges:
  1. capture the lightning strike to a preferred point
  2. conduct it to ground safely
  3. dissipate energy into earth
  4. bound to create equipotential ground plane
  5. protect incoming power circuits
  6. protect incoming telephone/data circuit

The overvoltage level, as the consequence of atmospheric discharge, has to be reduced to low enough safety value for the electric and electronic devices. Further are given average statistic parameters of atmospheric discharges, the geometry of external protection elements, their influence on the shape of electric field and how to use them in construction of the whole catching system. The technology of conducting current after lightning strike through special constructed conductor is shortly described.

The special emphasize is on the internal overvoltage protection: how to project the Surge Protection Devices-SPD and their proper choice. The areas of discussion are:
  1. Energetics
  2. Informatics
  3. Telecommunications
  4. The program of equipotential sparks based on own Gas Discharge Tube-GDT
The proper choice of SPD has to include the next starting parameters:
    a.) Maximal connecting voltage
    b.) Expected loading of transient appearances (Impulse current, Iimp, and Rated surge current, In)
    c.) Desired protection level, Up
    d.) In the case of damaging energetic system, that occurs overvoltage TOV, and telecommunication system what situation will be expected
    e.) coordination with other SPD in the protection system
    f.) Maximal allowed current
    g.) Frequency ranges

Further, a comparison is given between different SPD's: sparks, metal-oxide varistors and semiconductive protective elements.

Peter Gajsek,
Institute of Non-ionizing Radiation, Ljubljana, Slovenia

EMF Sources and Dosimetry

The industrialization and electrification of society has resulted in the exposure of population to a complex environment of electromagnetic fields (EMFs), which include static electric and magnetic fields, extremely low frequency fields (normally having frequencies up to about 300 Hz) and radiofrequency (RF) fields (3 kHz to 300 GHz). While EMFs in our environment extend over all frequency ranges, the dominant exposure to the general public is due to the generation, distribution and domestic use of electricity at a power frequency of 50 or 60 Hz. Public exposures may also result from high frequency sources such as computer monitors, microwave ovens, radio and TV broadcast stations, radio communication equipment, security and surveillance systems, and traffic and navigation radars. In many workplaces, employees may be exposed to high intensity EMFs during the course of their jobs. This includes individuals working in electrical utility substations and persons working near active power lines, induction furnaces, RF heating devices, and radio and TV antennas.

The past 15 years have seen remarkable advances in personal communication technology and a rapid expansion in the use of mobile phones. The rapid growth of the mobile phone industry has resulted in the installation of numerous base stations to relay phone calls. Base station antennas appear everywhere in both urban and rural areas, either mounted on freestanding towers or attached to rooftops or the sides of buildings. In the assessment of risks from EMF exposures, it is important to understand the characteristics of exposure fields and how they interact with biological organisms. EMFs from different sources may have widely different characteristics, and thus their effects on biological organisms should not be assumed to be the same.

Thus, accurate dosimetry is a critical part of any scientific effort to assess the effects of electromagnetic fields (EMF) on biological systems. In addition, conducting high quality dosimetry and reporting detailed descriptions of the dosimetry are essential to permit precise replications of experiments by independent laboratories. Dosimetry includes the prediction and/or measurement of the incident and internal fields. These fields can be quite different, depending upon the characteristics of the object, including: size and shape, electrical properties, orientation with respect to the incident field, and the frequency of the incident field. The development of mathematical dosimetry modeling techniques and relatively powerful computer hardware has resulted in computer modeling as a principal tool in assessing the biological dose resulting from EMF exposure. Only with the use of realistic anatomical models and methods such as the finite difference time domain (FDTD) has the ability to estimate both whole body and localized specific absorption rate (SAR) values become possible.

Because of the complex mechanisms of interaction, the study of the biological effects of EMFs requires knowledge in a wide range of disciplines, including engineering, biology, chemistry, environmental health, mathematics, medicine and physics.

Tadej Kotnik,
University of Ljubljana, Faculty of Electrical Engineering, Ljubljana, Slovenia

Dielectric Power Dissipation in Biological Cells Exposed to RF Fields

Michael Kundi,
Medical University of Vienna, Institute of Environmental Health, Austria

Biological and Health Relevant Effects From Exposure to High-Frequency EMFs

Although there are natural sources of electromagnetic fields (EMFs), there is no significant level of natural energy at radio or microwave frequencies (RF/MW). Whenever there are exposures to factors for which no evolutionary adaptation occurred, we have to start with the assumption that such exposures pose a health hazard. Only a few years after the first experimental steps towards wireless communication, radio stations were operating all over the world. Subsequently remote sensing systems, television, telecommunication systems and other applications were introduced that led to a considerable increase of environmental exposure levels. During world war II and in the early 1950s some physicians and other scientists - especially in military and occupational settings - observed effects in subjects exposed to presumably high levels of microwave energy that can now be described as thermal effects. Although the microwave oven was already invented, early experiments that demonstrated hemorrhages and disseminated tissue damage in rabbits after exposure to high-frequency fields were answered with disbelief by the scientific community. The same happened with early reports of potential chronic effects of radar exposure. Only after the epidemiological study of Wertheimer and Leeper, published in 1979, that indicated a leukemogenic effect of power-line frequencies, a renewed interest in effects of weak chronic exposures resulted in a number of studies that included exposures to RF/MW fields. Up to now about 50 epidemiological studies, mainly with respect to RF/MW exposure and cancer, have been published. Although the majority of these studies show indications of an increased risk, methodological limitations allow no far reaching conclusions. It is significant that despite a decade long controversy about potential long-term effects of RF/MW exposure, until the early 1980s not a single animal experiment has been conducted that addressed this issue. Since then about 25 long- and medium-term animal assays have been reported, however, not a single one has been conducted following the widely accepted guidelines of NTP (the US National Toxicological Program). Most of these studies cannot contribute to risk evaluation due to methodological shortcomings. Especially after the dramatic success of mobile telecommunication there is an increased interest in potential health effects of long-term exposures. However, present guidelines are predominantly designed to limit immediate acute effects. Although long-term low-level effects cannot be excluded the evidence is insufficient as a basis for deriving exposure limits for to the whole spectrum of RF/MW fields. In environmental toxicology risk assessment is based on three sources of data: epidemiological studies, human and animal experiments, and in vitro studies. There is evidence of harmful effects of RF/MW fields from all these sources of data. However, there are two main problems that have prohibited the inclusion of these data into the derivation of guideline levels: there is no accepted mechanism of action that allows extrapolation to other exposure conditions (and hence there is no basis for generalization); and there is a controversy whether and which biological effects are health relevant. Also this latter problem is related to the mechanism of action, because the same biological effect, depending on the mechanism that produced it, can be adverse, indifferent, or even beneficial. The great challenge is to join widely different disciplines of science in the effort to solve a puzzle that cannot efficiently be tackled by any of the disciplines alone.

Contact person for the Workshop on Non-ionizing Electromagnetic Fields:
From Overvoltage, Overcurrent and Electrostatic Discharge Protection to Bioeffects
Prof. Dr. Bruno Cvikl
Faculty of Civil Engineering
Chair of Applied Physics
Trzaska 25
Si-2000 Maribor, SLOVENIA
tel. +386 2 2294362,+386 1 5885239
fax. +386 2 2524179
email: cvikl@uni-mb.si