Radio frequency

Radio frequency, or RF, is a carrier, or alternating current with or without a signal, at a frequency that can radiate, or propagate, if not shielded. Such frequencies account for the following parts of the electromagnetic spectrum:

Very low frequency VLF: 3-30 kHz

Low frequency LF: 30-300 kHz

Medium frequency MF: 300-3000 kHz

High frequency HF: 3-30 MHz

Very high frequency VHF: 30-300 MHz

Ultra high frequency UHF: 300-3000 MHz

Super high frequency SHF[?]: 3-30 GHz[?]

Extremely high frequency EHF[?]: 30-300 GHz

Note: above 300 GHz, the absorption of electromagnetic radiation by Earth's atmosphere is so great that the atmosphere is effectively opaque to higher frequencies of electromagnetic radiation, until the atmosphere becomes transparent again in the so-called infrared and optical window freqency ranges.

Analog signals that are not RF include IF (intermediate frequency) and AF (audio frequency[?], 20-20000 Hz).

Electrical connectors designed to work at radio frequencies are known as RF connectors. RF is also the name of a standard audio/video connector, also called BNC (BayoNet Connector).

Named Frequency Bands

• Band III[?] - 174-245 MHz
• L-Band[?] - 1.2-1.7 GHz
• S-Band[?] - 1.7-2.4 GHz
• C-Band - 5.8-6.5 GHz
• X-Band[?] - 7.2-8.5 GHz
• Ku-Band - 13.7-14.5 GHz
• K-Band[?] - 21.2-23.6 GHz