1、 Report ITU-R SM.2180(09/2010)Impact of industrial, scientific and medical (ISM) equipment on radiocommunication services SM SeriesSpectrum managementii Rep. ITU-R SM.2180 Foreword The role of the Radiocommunication Sector is to ensure the rational, equitable, efficient and economical use of the rad
2、io-frequency spectrum by all radiocommunication services, including satellite services, and carry out studies without limit of frequency range on the basis of which Recommendations are adopted. The regulatory and policy functions of the Radiocommunication Sector are performed by World and Regional R
3、adiocommunication Conferences and Radiocommunication Assemblies supported by Study Groups. Policy on Intellectual Property Right (IPR) ITU-R policy on IPR is described in the Common Patent Policy for ITU-T/ITU-R/ISO/IEC referenced in Annex 1 of Resolution ITU-R 1. Forms to be used for the submission
4、 of patent statements and licensing declarations by patent holders are available from http:/www.itu.int/ITU-R/go/patents/en where the Guidelines for Implementation of the Common Patent Policy for ITU-T/ITU-R/ISO/IEC and the ITU-R patent information database can also be found. Series of ITU-R Reports
5、 (Also available online at http:/www.itu.int/publ/R-REP/en) Series Title BO Satellite delivery BR Recording for production, archival and play-out; film for television BS Broadcasting service (sound) BT Broadcasting service (television) F Fixed service M Mobile, radiodetermination, amateur and relate
6、d satellite services P Radiowave propagation RA Radio astronomy RS Remote sensing systems S Fixed-satellite service SA Space applications and meteorology SF Frequency sharing and coordination between fixed-satellite and fixed service systems SM Spectrum management Note: This ITU-R Report was approve
7、d in English by the Study Group under the procedure detailed in Resolution ITU-R 1. Electronic Publication Geneva, 2011 ITU 2011 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without written permission of ITU. Rep. ITU-R SM.2180 1 REPORT ITU-R SM.2180 I
8、mpact of industrial, scientific and medical (ISM) equipment on radiocommunication services (2010) TABLE OF CONTENTS Page 1 Introduction 2 2 Definition and frequency bands 2 3 Applications of ISM equipment . 3 4 Characteristics of radiation . 5 4.1 Induction heating 6 4.2 Dielectric heating 7 4.3 Med
9、ical applications . 8 5 Analysis of potential interference . 8 5.1 CISPR interference models . 8 5.1.1 Basic model 8 5.1.2 CISPR model for the frequency range below 1 GHz . 10 5.1.3 CISPR model for the frequency range above 1 GHz . 13 5.2 Review of CISPR limits 15 5.3 Characteristics and protection
10、criteria of radiocommunication services 18 5.4 Field measurement of radiation 19 5.4.1 Magnetic resonance imaging . 20 5.4.2 Induction heating equipment 21 5.4.3 Microwave oven . 21 6 Conclusion 22 References 23 Attachment 1 Measurement results of MRI 24 Attachment 2 Measurement results of induction
11、 heating equipment 30 2 Rep. ITU-R SM.2180 1 Introduction The industrial, scientific and medical (ISM) equipment for non-communications applications has been extensively used for various purposes, i.e., drying, melting, heating, welding, thawing, cooking, tempering, soldering, brazing, moulding, ima
12、ging, and so on. Recently, ITU-R developed the Recommendation ITU-R SM.1056 regarding the protection of radio services from the emission radiated by the ISM equipment. The emission limits for ISM equipment recommended by ITU-R has reference to the limits of the International Special Committee on Rad
13、io Interference (CISPR) Publication 11. It is known that the limits of CISPR 11 are based on the interference model provided in CISPR 16-4-4. It is expected that both ISM equipment and radio transceivers are used in close proximity with each other since the number of these RF devices is on the incre
14、ase. Thus, there is a need to examine impact of the ISM equipment on radio services. 2 Definition and frequency bands This section is concerned with: 1. the definitions of ISM; 2. the frequency bands; 3. interference from ISM equipment as given in the Radio Regulations (RR). The following is excerpt
15、ed from the RR regarding the three items: 1. Definition “1.15 industrial, scientific and medical (ISM) applications (of radio frequency energy): Operation of equipment or appliances designed to generate and use locally radio frequency energy for industrial, scientific, medical, domestic or similar p
16、urposes, excluding applications in the field of telecommunications.” 2. Frequency bands “5.138 The following bands: 6 765-6 795 kHz (centre frequency 6 780 kHz), 433.05-434.79 MHz (centre frequency 433.92 MHz) in Region 1 except in the countries mentioned in No. 5.280, 61-61.5 GHz (centre frequency
17、61.25 GHz), 122-123 GHz (centre frequency 122.5 GHz), and 244-246 GHz (centre frequency 245 GHz). are designated for industrial, scientific and medical (ISM) applications. The use of these frequency bands for ISM applications shall be subject to special authorization by the administration concerned,
18、 in agreement with other administrations whose radiocommunication services might be affected. In applying this provision, administrations shall have due regard to the latest relevant ITU-R Recommendations. 5.280 In Germany, Austria, Bosnia and Herzegovina, Croatia, The Former Yugoslav Republic of Ma
19、cedonia, Liechtenstein, Montenegro, Portugal, Serbia, Slovenia and Switzerland, the band 433.05-434.79 MHz (centre frequency 433.92 MHz) is designated for industrial, scientific and medical (ISM) applications. Radiocommunication services of these countries operating within this band must accept harm
20、ful interference which may be caused by these applications. ISM equipment operating in this band is subject to the provisions of No. 15.13 (WRC-07)”. Rep. ITU-R SM.2180 3 “5.150 The following bands: 13 553-13 567 kHz (centre frequency 13 560 kHz), 26 957-27 283 kHz (centre frequency 27 120 kHz), 40.
21、66-40.70 MHz (centre frequency 40.68 MHz), 902-928 MHz in Region 2 (centre frequency 915 MHz), 2 400-2 500 MHz (centre frequency 2 450 MHz), 5 725-5 875 MHz (centre frequency 5 800 MHz), and 24-24.25 GHz (centre frequency 24.125 GHz) are also designated for industrial, scientific and medical (ISM) a
22、pplications. Radiocommunication services operating within these bands must accept harmful interference which may be caused by these applications. ISM equipment operating in these bands is subject to the provisions of No. 15.13.” 3. Interference from ISM equipment “15.12 8 Administrations shall take
23、all practicable and necessary steps to ensure that the operation of electrical apparatus or installations of any kind, including power and telecommunication distribution networks, but excluding equipment used for industrial, scientific and medical applications, does not cause harmful interference to
24、 a radiocommunication service and, in particular, to a radionavigation or any other safety service operating in accordance with the provisions of these Regulations1. 15.13 9 Administrations shall take all practicable and necessary steps to ensure that radiation from equipment used for industrial, sc
25、ientific and medical applications is minimal and that, outside the bands designated for use by this equipment, radiation from such equipment is at a level that does not cause harmful interference to a radiocommunication service and, in particular, to a radionavigation or any other safety service ope
26、rating in accordance with the provisions of these Regulations1.” 3 Applications of ISM equipment In accordance with Recommendation ITU-R SM.1056, examples of ISM applications are as follows: Induction heating equipment (below 1 MHz) Domestic induction cookers. Metal melting. Billet heating. Tube wel
27、ding. Soldering and brazing. Component heating. Spot welding. Selective surface heat treating of metal parts. Semiconductor crystal growing and refining. Seam bonding of auto body surfaces. Package sealing. Heating strip steel for galvanizing, annealing and paint drying. 115.12.1 and 15.13.1 In this
28、 matter, administrations should be guided by the latest relevant ITU-R Recommendations. 4 Rep. ITU-R SM.2180 RF dielectric heating equipment (1-100 MHz) Veneer and lumber drying. Textile drying. Fibreglass drying. Paper and paper coating drying. Plastic pre-heating. Plastic welding and moulding. Foo
29、d post baking and drying. Meat and fish thawing. Foundry core drying. Glue drying. Film drying. Adhesive curing. Material preheating. Medical equipment Short-wave and microwave diathermy and hyperthermia equipment. Electrical surgical units (ESU). Magnetic resonance imaging (MRI). Ultrasonic diagnos
30、tic imaging. Microwave equipment (above 900 MHz) Domestic and commercial microwave ovens. Food tempering, thawing and cooking. UV paint and coating curing. Rubber vulcanization. Pharmaceutical processing. Miscellaneous equipment RF excited arc welders. Spark erosion equipment. Laboratory and scienti
31、fic equipment Signal generators. Measuring receivers. Frequency counters. Flow meters. Spectrum analysers. Weighing machines. Chemical analysis machines. Electronic microscopes. Switched mode power supplies (not incorporated in an equipment). Table 1 shows various applications of ISM equipment by op
32、erating frequency. Rep. ITU-R SM.2180 5 TABLE 1 Example applications of ISM equipment Frequency (MHz) Applications Below 0.15 Industrial induction heating (welding and melting of metals) Ultrasonic cleaning (15-30 kHz) Medical applications (ultrasonic diagnostic imaging) 0.15-1 Induction heating (he
33、at treating, package sealing, welding and melting of metals) Ultrasonic medical diagnostics 1-10 Surgical diathermy (1-10 MHz dampened wave oscillator) Wood gluing and wood curing (3.2 and 6.5 MHz) Valve induction generators production of semi-conductor material RF arc stabilized welding (1-10 MHz d
34、ampened wave oscillator) 10-100 Dielectric heating (the majority operate on frequencies in the ISM bands at 13.56, 27.12 and 40.68 MHz, but many also operate on frequencies outside the ISM bands): Ceramics Foundry core drying Textile drying Business products (books, paper, gluing and drying) Food (p
35、ost baking, meat and fish thawing) Solvent drying Wood drying and gluing (veneer and lumber drying) General dielectric drying Plastic heating (die sealing and plastic embossing) Medical applications: Medical diathermy (27 MHz) Magnetic resonance imaging (10-100 MHz in large shielded rooms) 100-1 000
36、 Food processing (915 MHz) Medical applications (433 MHz) RF plasma generators Rubber vulcanization (915 MHz) Above 1 000 RF plasma generators Domestic microwave ovens (2 450 MHz) Commercial microwave ovens (2 450 MHz) Rubber vulcanization (2 450 MHz) RF excited ultraviolet curing 4 Characteristics
37、of radiation In general, the radiation characteristics of ISM equipment depend on operating frequency, waveform of RF source, structure of radiator, surrounding structure of radiator, etc. Also, the radiation characteristics depend on distance from ISM equipment. Using the conventional antenna theor
38、y, the space surrounding a radiator is subdivided into three regions: a) reactive near-field; b) radiating near-field (Fresnel); c) far-field (Fraunhofer) regions as shown in Fig. 1. Therefore, the radiation characteristics impacting on radiocommunication devices may be different according to the di
39、stance between radiators and victims. 6 Rep. ITU-R SM.2180 FIGURE 1 Field regions of an antenna Report SM.2180-01Far-field(Fraunhofer)RadiatingNear-field(fresnel)Reactiverear-field4.1 Induction heating Induction heating is a process which is used to bond, harden, or soften metals or other conductive
40、 materials with the application of the transformer theory. When an alternating electrical current is applied to the primary of a transformer, an alternating magnetic field is created. According to Faradays Law, if the secondary of the transformer is located within the magnetic field, an electric cur
41、rent will be induced, which is called an eddy current. In basic induction heating equipment, the coil serves as the transformer primary and the target conductor to be heated becomes a short circuit secondary. Since the shape of the induction heating coil is similar to a circular loop antenna, the ra
42、diation characteristics of induction heating coil are also similar to those of a circular loop antenna. Especially, since the operating frequency for induction heating is lower than 1 MHz, the wavelength is greater than 300 m, which is very large compared with the radius of induction heating coil. T
43、herefore, the induction heating coil can be considered as a small circular loop antenna. FIGURE 2 Geometry for circular loop antenna Report SM.2180-02zpyxaI0Rep. ITU-R SM.2180 7 When a radiocommunication system locates near the induction heating coil (kr 1), the predominant electromagnetic fields ca
44、n be approximated as: jkrerIkaH024sin)(=(5) jkrerIkaE024sin)( =(6) 0=EEHErr(7) The electric and magnetic fields are in time-phase and inversely proportional to r. The electric and magnetic fields of the small loop in the far-field region are perpendicular to each other and transverse to the directio
45、n of propagation. They form a uniform spherical plane wave whose wave impedance is equal to the intrinsic impedance of the medium. 4.2 Dielectric heating Dielectric heating equipment is to heat targeted dielectric material such as food, textile, lumber, etc. This is accomplished by using microwave r
46、adiation to heat polarized molecules within dielectric materials. Dielectric heating equipment consists of a RF power generator such as magnetron, a cavity or chamber, a waveguide, and a RF power controller. In general, the cavity is composed of metal plates and the microwaves produced by magnetron
47、are reflected within the metal wall of the cavity where they are absorbed by dielectrics. 8 Rep. ITU-R SM.2180 If the dielectric heating equipment is totally enclosed in a metal structure, no radiation is supposed to be emitted from the equipment. Since dielectric materials are placed through a door
48、 in the cavity, microwave leakage occurs through the small gap caused by the opening and closing of the door, which serves as aperture antennas. Thus, the radiation characteristics of dielectric heating equipment are similar to those of aperture antennas. For example, wavelength of microwaves for di
49、electric heating equipment is around 10 cm30 m. Domestic microwave ovens use 2.45 GHz and its wavelength is about 12.2 cm. Since this wavelength is not greater than the dimension of the equipment, the aperture size or length becomes comparable to wavelength. The radiation emitted from the dielectric heating equipment may act as the radiation from a phased array antenna. 4.3 Medical applications Magnetic resonance imaging (MRI), or nuclear ma
