Radio frequency

From Freepedia

Radio Wave is also the name of a commercial radio station in Blackpool, North West England. See Radio Wave 96.5.

Image:Atmospheric electromagnetic transmittance or opacity.jpg Radio frequency, or RF, refers to that portion of the electromagnetic spectrum in which electromagnetic waves can be generated by alternating current fed to an antenna. Such frequencies account for the following parts of the spectrum shown in the table below.

Contents 1 Radio frequency spectrum 2 Named frequency bands 2.1 General 2.2 Amateur radio frequencies 2.3 IEEE US 2.4 EU, NATO 3 See also 4 External links

Radio frequency spectrum

Band name	Abbr	ITU band	Frequency Wavelength	Example uses
			< 3 Hz > 100,000 km
Extremely low frequency	ELF	1	3–30 Hz 100,000 km – 10,000 km
Super low frequency	SLF	2	30–300 Hz 10,000 km – 1000 km
Ultra low frequency	ULF	3	300–3000 Hz 1000 km – 100 km
Very low frequency	VLF	4	3–30 kHz 100 km – 10 km	Military communication
Low frequency	LF	5	30–300 kHz 10 km – 1 km	Navigation, time signals, AM longwave broadcasting
Medium frequency	MF	6	300–3000 kHz 1 km – 100 m	AM broadcasts
High frequency	HF	7	3–30 MHz 100 m – 10 m	Shortwave broadcasts and amateur radio
Very high frequency	VHF	8	30–300 MHz 10 m – 1 m	FM and television broadcasts
Ultra high frequency	UHF	9	300–3000 MHz 1 m – 100 mm	television broadcasts, wireless LAN
Super high frequency	SHF	10	3–30 GHz 100 mm – 10 mm	microwave devices, mobile phones
Extremely high frequency	EHF	11	30–300 GHz 10 mm – 1 mm
			Above 300 GHz < 1 mm

Note:</br> 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 frequency ranges.

The ELF, SLF, ULF, and VLF bands overlap the AF (audio frequency) spectrum, which is approximately 20–20,000 Hz. However, sounds are transmitted by atmospheric compression and expansion, and not by electromagnetic energy.

Named frequency bands

General

• Band III - 174–245 MHz
• ISM band ... specific frequencies vary

Amateur radio frequencies

The range of allowed frequencies vary between countries. These are just some of the more common bands. In the article about amateur radio is another list.

Band	Frequency range
160 m	1.815 to 1.89 MHz
80 m	3.5 to 3.8 MHz
40 m	7 to 7.1 MHz
30 m	10.1 to 10.15 MHz
20 m	14 to 14.35 MHz
15 m	21 to 21.45 MHz
12 m	24.89 to 24.99 MHz
10 m	28.0 to 29.7 MHz
6 m	50.08 to 51 MHz
2 m	144 to 146 MHz
70 cm	430 to 440 MHz
23 cm	1240 to 1300 MHz

IEEE US

Band	Frequency range
I band	to 0.2GHz
G band	0.2 to 0.25 GHz
P band	0.25 to 0.5 GHz
L band	0.5 to 1.5 GHz
S band	2 to 4 GHz
C band	4 to 8 GHz
X band	8 to 12 GHz
Ku band	12 to 18 GHz
K band	18 to 26 GHz
Ka band	26 to 40 GHz
V band	40 to 75 GHz
W band	75 to 111 GHz

EU, NATO

Band	Frequency range
A band	to 0.25 GHz
B band	0.25 to 0.5 GHz
C band	0.5 to 1.0 GHz
D band	1 to 2 GHz
E band	2 to 3 GHz
F band	3 to 4 GHz
G band	4 to 6 GHz
H band	6 to 8 GHz
I band	8 to 10 GHz
J band	10 to 20 GHz
K band	20 to 40 GHz
L band	40 to 60 GHz
M band	60 to 100 GHz

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See also

• Radio propagation
• Frequency allocation

Radio spectrum
	ELF		SLF		ULF/VF		VLF		LF/LW		MW		HF/SW		VHF		UHF		SHF		EHF
3 Hz		30 Hz		300 Hz		3 kHz		30 kHz		300 kHz		3 MHz		30 MHz		300 MHz		3 GHz		30 GHz		300 GHz

Electromagnetic Spectrum Gamma ray | X-ray | Ultraviolet | Optical spectrum | Infrared | Terahertz radiation | Microwave | Radio waves Optical (visible) spectrum: Violet | Indigo | Blue | Cyan | Green | Yellow | Orange | Red

External links

• Radio and light waves conversion: frequency to wavelength and vice versa