Frequency Bands

Frequency bands provide a structure for the classification of electromagnetic waves based on frequency. Essentially, frequency bands allow us to subdivide the most common types of electromagnetic waves in a structure that is useful for radio communications. The classification system itself is called the radio spectrum.

The lowest frequency band (ITU Band 1) is called “Extremely Low Frequency” and includes waves that have frequencies between 3 and 30 Hz. The highest frequency band (ITU Band 12) is called “Tremendously High Frequency” and includes frequencies from 300 GHz to 3 THz.

Lower frequencies have longer wavelengths and lower energy, while higher frequencies have shorter wavelengths and higher energy.

This system is highly useful in radio and satellite communications. Electronics used in communications will typically have circuits that allow for tuning within or across bands using filter circuits.

Table of Radio Spectrum Frequency Bands

Band Name	Abbreviation	Frequency	Wavelength	ITU Band
Extremely Low Frequency	ELF	3 Hz – 30 Hz	100 Mm – 10 Mm	1
Super Low Frequency	SLF	30 Hz – 300 Hz	10 Mm – 1 Mm	2
Ultra Low Frequency	ULF	300 Hz – 3 kHz	1 Mm – 100 km	3
Very Low Frequency	VLF	3 kHz – 30 kHz	100 km – 10 km	4
Low Frequency	LF	30 kHz – 300 kHz	10 km – 1 km	5
Medium Frequency	MF	300 kHz – 3 MHz	1 km – 100 m	6
High Frequency	HF	3 MHz – 30 MHz	100 m – 10 m	7
Very High Frequency	VHF	30 MHz – 300 MHz	10 m – 1 m	8
Ultra High Frequency	UHF	300 MHz – 3 GHz	1 m – 100 mm	9
Super High Frequency	SHF	3 GHz – 30 GHz	100 mm – 10 mm	10
Extremely High Frequency	EHF	30 GHz – 300 GHz	10 mm – 1 mm	11
Tremendously High Frequency	THF	300 GHz – 3 THz	1 mm – 100 µm	12

Electromagnetic Frequency and Wavelength

The frequency and wavelength of electromagnetic radiation is always linked by the speed of light:

Wavelength (λ) x Frequency (f) = Speed of Light (c)
λf = c

This is why the wavelength decreases as frequency is increased.

The energy of the wave is linearly proportional to the frequency. A constant is required for the two terms to equal each other. This is called Planck’s constant and is an important topic in physics:

Energy (E) = Frequency (f) x Planck’s constant (h)
E = hf