Frequency Ranges and Radio Licensing Regulations Frequency Ranges Used Because RFID systems generate and radiate electromagnetic waves, they are legally classified as radio systems. The function of other radio services must under no circumstances be disrupted or impaired by the operation of RFID systems. | RFID Handbook Fundamentals and Applications in Contactless Smart Cards and Identification Second Edition Klaus Finkenzeller 5 Copyright 2003 John Wiley Sons Ltd. ISBN 0-470-84402-7 Frequency Ranges and Radio Licensing Regulations Frequency Ranges Used Because RFID systems generate and radiate electromagnetic waves they are legally classified as radio systems. The function of other radio services must under no circumstances be disrupted or impaired by the operation of RFID systems. It is particularly important to ensure that RFID systems do not interfere with nearby radio and television mobile radio services police security services industry marine and aeronautical radio services and mobile telephones. The need to exercise care with regard to other radio services significantly restricts the range of suitable operating frequencies available to an RFID system Figure . For this reason it is usually only possible to use frequency ranges that have been reserved specifically for industrial scientific or medical applications. These are the frequencies classified worldwide as ISM frequency ranges Industrial-Scientific-Medical and they can also be used for RFID applications. In addition to ISM frequencies the entire frequency range below 135 kHz in North and South America and Japan 400 kHz is also suitable because it is possible to work with high magnetic field strengths in this range particularly when operating inductively coupled RFID systems. The most important frequency ranges for RFID systems are therefore 0-135 kHz and the ISM frequencies around not yet available in Germany MHz MHz MHz MHz MHz MHz not in Europe GHz GHz and GHz. An overview of the estimated distribution of RFID transponders at the various frequencies is shown in Figure . Frequency range 9-135 kHz The range below 135 kHz is heavily used by other radio services because it has not been reserved as an ISM frequency range. The .
