RFID Frequencies

Frequency Ranges

The need to exercise care with regard to other radio services significantly restricts the range of suitable operating frequencies available to an RFID system. For this reason, it is usually only possible to use frequency ranges that have been reserved specifically for industrial, scientific or medical applications or for short range devices. These are the frequencies classified worldwide as ISM frequency ranges (Industrial-Scientific-Medical) or SRD frequency ranges, and they can also be used for RFID applications.

frequency range comment allowed fieldstrength / transmission power
< 135 kHz low frequency, inductive coupling 72 dBµA/m max
3.155 ... 3.400 MHz EAS 13.5 dBµA/m
6.765 .. 6.795 MHz medium frequency (ISM), inductive coupling 42 dBµA/m
7.400 .. 8.800 MHz medium frequency, used for EAS (electronic article surveilance) only 9 dBµA/m
13.553 .. 13.567 MHz medium frequency (13.56 MHz, ISM), inductive coupling, wide spread usage for contactless smartcards (ISO 14443, MIFARE, LEGIC, ...), smartlabels (ISO 15693, Tag-It, I-Code, ...) and item management (ISO 18000-3) 60(!) dBµA/m
26.957 .. 27.283 MHz medium frequency (ISM), inductive coupling, special applications only 42 dBµA/m
433 MHz UHF (ISM), backscatter coupling, rarely used for RFID 10 .. 100 mW
865 .. 868 MHz UHF (RFID only), Listen before talk 100 mW ERP
Europe only
865.6 .. 867.6 MHz UHF (RFID only), Listen before talk 2W ERP (=3.8W EIRP)
Europe only
865.6 .. 868 MHz UHF (SRD), backscatter coupling, new frequency, systems under developement 500 mW ERP,
Europe only
902 .. 928 MHz UHF (SRD), backscatter coupling, several systems 4 W EIRP - spread spectrum, USA/Canada only
2.400 .. 2.483 GHz SHF (ISM), backscatter coupling, several systems, 4 W - spread spectrum, USA/Canada only
2.446 .. 2.454 GHz SHF (RFID and AVI (automatic vehicle identification)) 0.5 W EIRP outdoor
4 W EIRP, indoor
5.725 .. 5.875 GHz SHF (ISM), backscatter coupling, rarely used for RFID 4 W USA/Canada,
500 mW Europe

Picture: Frequency-ranges used for RFID-systems shown with the corresponding field strength and power levels.