AEI Conference 2013 S LOVAK ELECTROTECHNICAL SOCIETY INTERNATIONAL CONFERENCE ON APPLIED ELECTRICAL ENGINEERING AND INFORMATICS 2013 AEI 3 S EPTEMBER 02 – 10, ITALY K SLOVAK REPUBLIC EDITOR: LIBERIOS VOKOROKOS ISBN 978-80-553-1459-4 3 AEI Conference 2013 ISBN: 978-80-553-1459-4 2013 ice, Slovak Republic 2013 All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior written permission of the publisher. No responsibility is assumed by the publisher for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions or ideas contained in the material herein. Editor: Liberios Vokorokos Published by the Faculty of Electrical Enginnering and Informatics, Technical University ISBN 978-80-553-1459-4 3 AEI Conference 2013 LIST OF PAPERS TESTING OF ENHANCED DSR ROUTING PROTOCOL FOR TEMPORARY DISCONNECTED MOBILE AD-HOC NETWORKS 8 THE SELECTION OF THE CANDIDATES FOR OPPORTUNISTIC FORWARDING: STATE OF THE ART ubo J PAPAJ, Roman PALITEFKA 14 ANALYSIS AND VERIFICATION OF SECURITY PROTOCOLS USING SPI-CALCULUS 18 AN INTERNET APPLICATIONS BASED ON THE MULTI-AGENT SYSTEM 22 HARMONIC ANALYSIS OF CONVERTERS WITH PWM OUTPUT VOLTAGE CONTROL FOR TWO-PHASE MOTOR APPLICATIONS 26 POWER SYSTEM STABILITY IMPROVEMENT USING FACTS DEVICES Michal KOLCUN Jr. 32 AGILENT USING AS HUMAN-MACHINE Roman CIMBALA, 37 FACE ANALYSIS ALGORITHM Liberios VOKOROKOS, Eva CHOVANCOV 40 MEASURING OF SHIELDING EFFECTIVENESS OF WET MATERIALS IN THE FREQUENCY RANGE FROM 1 GHZ TO 13 GHZ Alexander 44 EXPERIENCE IN THE DIAGNOSTIC OF AERIAL MASTS 49 ISBN 978-80-553-1030-5 2 AEI Conference 2013 MEASURING OF SHIELDING EFFECTIVENESS OF WET MATERIALS IN THE FREQUENCY RANGE FROM 1 GHZ TO 13 GHZ , Iraida -mail: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected] ABSTRACT This paper deals with measuring of shielding effectiveness of electromagnetic field. The measurements were focused on shielding effectiveness while gradually drying out building materials in the range of high frequencies from 1 GHz to 13 GHz. The measured object was fiber cement board facade Eterplan and exterior facade board Natura Pro. Thickness of the boards were 8 mm. Keywords: shielding effectiveness, electromagnetic field, high frequencies 1. INTRODUCTION associated concept of electromagnetic compatibility. We are witnessing an increase of resources of electromagnetic radiation which in the past were not so 2. SHIELDING EFFECTIVENESS great. Wireless on the one hand provides convenience and speed of communication but on the other hand brings Shielding of electromagnetic field can be defined as a some negatives that are in the world more and more ability of material to defend of the penetration of the discussed topic. electromagnetic field. Various types of equipment use It should be noted that the sources of the shielding in various fields of our daily lives. This is electromagnetic field not only negatively affect the human mobile phones, mobile stations, wifi devices to provide body. A well-known example of the beneficial uses of internet through a variety of medical devices, source of electromagnetic radiation at higher frequencies communications networks, electronic devices and so on. This concept closely related with electromagnetic is the thermal hyperthermia which is described in [1]. compatibility. Electromagnetic compatibility could be Wireless communication is not only represented in the defined as the ability of devices to coexist in the same IT sector, but also the constant development in the electromagnetic environment [1] [3]. medical environment requires the use of this type of communication. In the medical field, there are many Quality shielding material are determined by three applications using wireless communication just for coefficients, KS shielding coefficient, absorption capturing and monitoring of the human body, the output coefficient A and a reflection coefficient R. With these data are collected as the human body. three factors closely related to the shielding effectiveness The wireless communication provides long-term SE. Shielding coefficient KS is determined by the electric monitoring activities of the human body even under field strength E, possibly based on the intensity of the severe conditions [2]. magnetic field H by the relation: We are exposed electromagnetic radiation everytime E H and everywhere. The increasing trend of volume of 2 2 (1) K S ; K S sources of electromagnetic radiation will still continue to E1 H1 increase. As an ordinary person we can not with our where E2 is electric field measured using the antenna senses perceive electromagnetic radiation. This mean that placed in the prescribed configuration within the human is so benevolent to potential threats. That is why it enclosure, E1 is electric field measured using the antenna is a topic of increasing sources of electromagnetic placed in the prescribed configuration in the absence of radiation and its impact on human body for the general the enclosure, H2 is magnetic field measured using the public so current. antenna placed in the prescribed configuration within the The opinions on this topic are different. On the one enclosure, H1 is magnetic field measured using the hand manufacturers of devices operating on the principle antenna placed in the prescribed configuration in the of electromagnetic field claiming that their funds are safe. absence of the enclosure And on the other stands the World Health Organization Shielding effectiveness SE is calculated using the which say opposite. The time of use of such devices is formula: relatively short. We can not say with certainty whether 1 H E these devices cause health risks or not. SE 20.log 20.log 1 20.log 1 dB (2) K H E Wide professional community more and more focused S 2 2 to resources of electromagnetic fields, their impact and the Formula varies for determining of the shielding effectiveness SE according to the frequency range. ISBN 978-80-553-1459- Measuring of Shielding Effectiveness of Wet ... According to [4], the shielding effectiveness is determined 3. WORKPLACE FOR THE PURPOSE OF by the relationship: MEASURING SHIELDING EFFECTIVENESS OF H V ELECTROMAGNETIC FIELD SE 20.log 1 20.log 1 dB (3) H V 2 2 Block diagram for the purpose of measuring of For the frequency range from 50 Hz to 20 MHz and for shielding effectiveness SE of the electromagnetic field is the frequency range from 20 MHz to 300 MHz and also the shown in Fig.1 and view to the workplace for the purpose same applies to the frequency range 300 MHz to 100 GHz of measuring of the shielding effectiveness in Fig.1 and Fig.2. This workplace consists of a pulse generator E1 P Agilent N5181A spectrum analyzer Agilent N9038A SE 20.log 10.log 1 dB (4) MXE EMI (Fig.2), the receiving antenna and transmitting E2 P2 antenna horn type (Fig.3). Measured object was placed at where H2, E2 is magnetic and electric field measured using the antenna placed in the prescribed configuration a distance of 30 cm from the transmitting antenna. The whole measurement was carried out in an anechoic within the enclosure, H1, E1 is magnetic and electric field measured using the antenna placed in the prescribed chamber at the Department of Electrical Power configuration in the absence of the enclosure, V is voltage Engineering of FEI TU and there is no extraneous 2 influence of electromagnetic field on the measurement. reading within the enclosure, V1 is voltage reading in the absence of the enclosure and P2 is power detected within the enclosure, P1 is power detected in absence of the enclosure. According to [5] shielding effectiveness is the sum of the reflection R, multiple reflection B and absorption A of electromagnetic field derived as [5]: SE A R B (5) . f 2t SE 15,4t 168,16 10log R 20log 1 e R where t is material thickness, is conductivity of shielding material, R is permeability of shielding material, f is frequency, is depth of penetration. For simplicity, it is possible to determine the shielding effectiveness SE as: SE A R (6) Fig. 1 The block diagram of measurement of shielding effectiveness t 1 SE 8,69. 20.log . 2 4 . r . 0 . where is permeability which is included permeability of the shielding material, 0 is permittivity of vacuum. From equation (6) we can see, the relative permeability and relative conductivity affect shielding effectiveness SE [5]. Shielding effectiveness can be calculated according to the relations (7-10) if the value of the transmitted signal is set in logarithmic units. SE E1 dB E2 dB (7) SE H1 dB H 2 dB (8) SE V1 dB V2 dB (9) SE P dB P dB (10) 1 2 Formula (7), (8), (9), (10) is used according to the Fig. 2 View of the measuring instruments available measuring equipments. ISBN 978-80-553-1459-4 2013 AEI Conference 2013 46 Fig. 4 Dependence of change shielding effectiveness of electromagnetic field on the time from 1 GHz to 6 GHz for Eterplan Fig. 3 View of the measuring antennas Measured object were fiber cement board facade Eterplan and exterior facade board Natura Pro. Thickness of the plates was 8 mm. Board size were 0.7 x 0.7 m. Shielding effectiveness was measured in the frequency range from 1 GHz to 13 GHz in steps of 1 GHz. The first step was measured electromagnetic fields dry plates in frequency from 1 GHz up to 13 GHz in steps of 1 GHz. After this measurement the plate sprayed volume of water corresponding with the rainfall 0.15 mm.