Typical frequencies for devices generating radio frequency fields

Radio frequency fields	100 kHz to 300 GHz
Radio transmitters operated in the long wave range	30 kHz to 300 kHz
Welding devices	up to a few hundred kHz
Electrosurgery systems	some hundred kHz
clinical MRI devices use radio frequency fields in addition to static and intermediate frequency fields	63 MHz
Mobile telephony: GSM 900	about 900 MHz
Mobile telephony: GSM 1800	about 1800 MHz
Mobile telephony: UMTS 2100	about 2100 MHz
anti-theft devices	Ranging from some tens of Hz to a few GHz depending on the type of system

Source: SCENIHR  Possible effects of Electromagnetic Fields (EMF) on Human Health