Radio Electromagnetic Spectrum Frequency Bands

This chart shows the relative positions of the most common frequency bands, and is not to scale.

ELF = Extremely Low Frequency
VF = Voice Frequency
VLF = Very Low Frequency
LF = Low Frequency
MF = Medium Frequency
HF = High Frequency
VHF = Very High Frequency
UHF = Ultra High Frequency
SHF = Super High Frequency
EHF = Extremely High Frequency

If you do a search on the origin of the designations for the various frequency bands, what you will find that nobody really knows. I have seen some pretty bogus explanations for how the band designation came to be, but I seriously doubt that the letters were assigned in order to confuse the enemy during WWII, or that "X" band was named for "cross," like in the cross hairs of precision targeting radars.

There is some logic in the upper and lower frequencies of the bands, however. The "3x10ⁿ" frequencies derive from wavelength in meters. Recalling that the speed of light in air is 300,000 km/s, that means a 1 meter wavelength translates to a frequency of 300 MHz, 10 meters is 30 MHz, 100 meters is 3 MHz, etc.

At some point, some wise soul decided that it was time to start over at a single digit for L-band at 1 GHz. The new regions are in octaves, except for 3 GHz, to 8 GHz. If anyone knows why 12.5, 18, and 26.5 GHz band edges were chosen, I would appreciate your letting me know.

Regarding the Ku, K, and Ka bands, supposedly K was named after the German word for "short," as in shortwave - Kurz. Ku is supposedly for K-under and Ka is supposedly K-above. That, of course, is inconsistent since since the K, if is derives from Kurz in wavelength, so K-under would be a lower (lesser) wavelength (hence higher frequency) and K-above would be a longer (greater) wavelength (hence lower frequency). Mostly likely, the certain origins are buried with their progenitors.

High Level Divisions in Frequency Band Designations:

Extremely low-frequency (ELF) band: 30 Hz to 300 Hz (10 megameter down to 1 megameter)

Voice-frequency (VF) band: 300 Hz to 3 kHz (1 megameter to 100 kilometer)

Very low-frequency (VLF) band: 3 kHz to 30 kHz (100 km to 10 km)

Low-frequency (LF) band: 30 kHz to 300 kHz (10 km to 1 km)

Medium-frequency (MF) band: 300 kHz to 3 MHz (1 km to 100 m)

High-frequency (HF) band: 3 MHz to 30 MHz (100 m to 10 m)

Very high-frequency (VHF) band: 30 MHz to 300 MHz (10 m down to 1 m)

Ultra high-frequency (UHF) band: 300 MHz to 3 GHz (1 m to 10 cm)

Super high-frequency (SHF) band: 3 GHz to 30 GHz (1 cm to 1 cm)

Extremely high-frequency (EHF) band: 30 GHz to 300 GHz (1 cm down to 1 mm)

Widely Accepted Lettered Frequency Band Designations:

L band: 1 GHz to 2 GHz (30 cm to 15 cm)

S band: 2 GHz to 4 GHz (15 cm to 7.5 cm)

C band: 4 GHz to 8 GHz (7.5 cm to 3.75 cm)

X band: 8 GHz to 12 GHz (3.75 cm to 2.5 cm )

Ku band: 12 GHz to 18 GHz (2.5 cm to 1.67 cm)

K band: 18 GHz to 26.5 GHz (1.67 cm to 1.13 cm)

Ka band: 26.5 GHz to 40 GHz (1.13 cm to 7.5 mm)

Q band: 32 GHz to 50 GHz (9.38 mm to 6 mm)

U band: 40 GHz to 60 GHz (7.5 mm to 5 mm)

V band: 50 GHz to 75 GHz (6 mm to 4 mm)

W band: 75 GHz to 100 GHz (4 mm to 3.33 mm)

Alternate Lettered Frequency Band (UHF, SHF, EHF) Designations:

L band: 1.12 GHz to 1.7 GHz (26.8 cm to 17.6 cm)

LS band: 1.7 GHz to 2.6 GHz (17.6 cm to 11.5 cm)

S band: 2.6 GHz to 3.95 GHz (11.5 cm to 7.59 cm)

C (G) band: 3.95 GHz to 5.85 GHz (7.59 cm to 5.13 cm)

XN (J, XC) band: 5.85 GHz to 8.2 GHz (5.13 cm to 3.66 cm)

XB (H, BL) band: 7.05 GHz to 10 GHz (4.26 cm to 3 cm)

X band: 8.2 GHz to 12.4 GHz (3.66 cm to 2.42 cm)

Ku (P) band: 12.4 GHz to 18 GHz (2.42 cm to 1.67 cm)

K band: 18 GHz to 26.5 GHz (1.67 cm to 1.13 cm)

V (R, Ka) band: 26.5 GHz to 40 GHz (1.13 cm to 7.5 mm)

Q (V) band: 33 GHz to 50 GHz (9.09 mm to 6 mm)

M (W) band: 50 GHz to 75 GHz (6 mm to 4 mm)

E (Y) band: 60 GHz to 90 GHz (5 mm to 3.33 mm)

F (N) band: 90 GHz to 140 GHz (3.33 mm to 2.14 mm)

G (A) band: 140 GHz to 220 GHz (2.14 mm to 1.36 mm)

R band: 220 GHz to 325 GHz (1.36 mm to 0.923 mm)

Subdivided Lettered Frequency Band (VHF, UHF, SHF, EHF) Designations:

A band: 100 MHz to 250 MHz (3 m to 1.2 m)

B band: 250 MHz to 500 MHz (1.2 m to 60 cm)

C band: 500 MHz to 1 GHz (60 cm to 30 cm)

D band: 1 GHz to 2 GHz (30 cm to 15 cm)

E band: 2 GHz to 3 GHz (15 cm to 10 cm)

F band: 3 GHz to 4 GHz (10 cm to 7.5 cm)

G band: 4 GHz to 6 GHz (7.5 cm to 5 cm)

H band: 6 GHz to 8 GHz (5 cm to 3.75 cm)

I band: 8 GHz to 10 GHz (3.75 cm to 3 cm)

J band: 10 GHz to 20 GHz (3 cm to 1.5 cm)

K band: 20 GHz to 40 GHz (1.5 cm to 7.5 mm)

L band: 40 GHz to 60 GHz (7.5 mm to 5 mm)

M band: 60 GHz to 100 GHz (5 mm to 3 mm)

Commercial Broadcast Bands:

Longwave Radio: 150 – 290 kHz

AM Radio: 550 – 1640 kHz (1.640 MHz) (107 Channels, 10-kHz separation)

International Radio: 3 – 30 MHz

Shortwave Radio: 5.95 – 26.1 MHz (8 bands)

VHF Television (channels 2 – 4): 54 – 72 MHz

VHF Television (channels 5 – 6): 76 – 88 MHz

FM Radio: 88 – 108 MHz

VHF Television (channels 7 – 13): 174 – 216 MHz

UHF Television (channels 14 – 83): 470 – 890 MHz