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 NameAbbreviationFrequencyWavelengthITU Band
Extremely Low FrequencyELF3 Hz – 30 Hz100 Mm – 10 Mm1
Super Low FrequencySLF30 Hz – 300 Hz10 Mm – 1 Mm2
Ultra Low FrequencyULF300 Hz – 3 kHz1 Mm – 100 km3
Very Low FrequencyVLF3 kHz – 30 kHz100 km – 10 km4
Low FrequencyLF30 kHz – 300 kHz10 km – 1 km5
Medium FrequencyMF300 kHz – 3 MHz1 km – 100 m6
High FrequencyHF3 MHz – 30 MHz100 m – 10 m7
Very High FrequencyVHF30 MHz – 300 MHz10 m – 1 m8
Ultra High FrequencyUHF300 MHz – 3 GHz1 m – 100 mm9
Super High FrequencySHF3 GHz – 30 GHz100 mm – 10 mm10
Extremely High FrequencyEHF30 GHz – 300 GHz10 mm – 1 mm11
Tremendously High FrequencyTHF300 GHz – 3 THz1 mm – 100 µm12

Electromagnetic Frequency and Wavelength

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