Frequency Ranges and Radio Licensing Regulations - RFID: Fundamentals and Applications in Contactless Smart Cards and Identification - page 158

Frequency Ranges
and Radio Licensing
Regulations

5.1 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 circum-
stances 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 televi-
sion, 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 5.1). 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
andSouthAmericaandJapan: < 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 6.78 (not yet available in Germany), 13.56MHz,
27.125MHz, 40.68MHz, 433.92MHz, 869.0MHz, 915.0MHz (not

in Europe),

2.45GHz, 5.8 GHz and 24.125 GHz.
An overview of the estimated distribution of RFID transponders at the various
frequencies is shown in Figure 5.2.

5.1.1 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 propagation conditions in this long wave