hertz | Hz | cycles per second | 100 Hz | 1 Hz |
kilohertz | kHz | one thousand hertz | 103 Hz | 1,000 Hz |
megahertz | MHz | one million hertz | 106 Hz | 1,000,000 Hz |
gigahertz | GHz | one billion hertz | 109 Hz | 1,000,000,000 Hz |
terahertz | THz | one trillion hertz | 1012 Hz | 1,000,000,000,000 Hz |
Band | Frequency | Wavelength | Notes |
---|---|---|---|
S | 2.455 GHz | 4.827 in 12.261 cm |
obsolete |
X | 9.41 GHz | 1.254 in 3.186 cm |
Europe |
X | 9.90 GHz | 1.192 in 3.028 cm |
Europe |
X | 10.525 GHz | 1.121 in 2.848 cm |
USA |
Ku | 13.450 GHz | 0.878 in 2.229 cm |
Europe Middle East |
K | 24.125 GHz | 0.4892 in 1.243 cm |
USA, Australia, Europe |
K | 24.150 GHz | 0.4897 in 1.241 cm |
USA |
Ka | 33.4 - 36.0 GHz | 0.353 - 0.328 in 8.976 - 8.328 mm |
USA, Australia, Europe |
IR -- Infrared | 331.6 THz | 904 nm | Laser Radar |
Frequency Band Designations |
Military Radar Bands
Military radar band nomenclature, L, S, C, X, Ku, and K bands originated during World War II as a secret code so scientists and engineers could talk about frequencies without divulging them. After the war the codes were declassified and Ka band and millimeter (mm) were added. Military radar band nomenclature is widely used today in radar, satellite and terrestrial communications, and military electronic countermeasure applications.
Radar Band | Frequency | Notes |
---|---|---|
HF | 3 - 30 MHz | High Frequency |
VHF | 30 - 300 MHz | Very High Frequency |
UHF | 300 - 1000 MHz | Ultra High Frequency |
L | 1 - 2 GHz | |
S | 2 - 4 GHz | |
C | 4 - 8 GHz | |
X | 8 - 12 GHz | |
Ku | 12 - 18 GHz | |
K | 18 - 27 GHz | |
Ka | 27 - 40 GHz | |
mm | 40 - 300 GHz | millimeter wavelength |
Military HF, VHF, UHF same as Radio Band HF, VHF, UHF respectively.
ITU Radar Bands
The International Telecommunications Union (ITU) specifies bands designated for radar systems. The ITU radar bands are sub-bands of military designations.
ITU Band | Frequency |
---|---|
VHF | 138 - 144 MHz 216 - 225 MHz |
UHF | 420 - 450 MHz 890 - 942 MHz |
L | 1.215 - 1.400 GHz |
S | 2.3 - 2.5 GHz 2.7 - 3.7 GHz |
C | 5.250 - 5.925 GHz |
X | 8.500 - 10.680 GHz |
Ku | 13.4 - 14.0 GHz 15.7 - 17.7 GHz |
K | 24.05 - 24.25 GHz |
Ka | 33.4 - 36.0 GHz |
VHF -- Very High Frequency
UHF -- Ultra High Frequency
Radio Bands
Radio band designations are summarized below. Note that the radio band chart includes wavelength. In the early days of radio it was easier to measure wavelength than frequency.
Band | Nomenclature | Frequency | Wavelength |
---|---|---|---|
ELF | Extremely Low Frequency | 3 - 30 Hz | 100,000 - 10,000 km |
SLF | Super Low Frequency | 30 - 300 Hz | 10,000 - 1,000 km |
ULF | Ultra Low Frequency | 300 - 3000 Hz | 1,000 - 100 km |
VLF | Very Low Frequency | 3 - 30 kHz | 100 - 10 km |
LF | Low Frequency | 30 - 300 kHz | 10 - 1 km |
MF | Medium Frequency | 300 - 3000 kHz | 1 km - 100 m |
HF | High Frequency | 3 - 30 MHz | 100 - 10 m |
VHF | Very High Frequency | 30 - 300 MHz | 10 - 1 m |
UHF | Ultra High Frequency | 300 - 3000 MHz | 1 m - 10 cm |
SHF | Super High Frequency | 3 - 30 GHz | 10 - 1 cm |
EHF | Extremely High Frequency | 30 - 300 GHz | 1 cm - 1 mm |
ECM Bands
The electronic countermeasures (ECM) industry has it's own band designations.
|
Sound Waves |
Sound waves are air pressure waves that travel at 765 mph at sea level, not like electromagnetic radio or radar waves that travel at the speed of light. Sound is a pressure wave of vibrating air molecules, and does not exits in the vacuum of outer space.
Most people at best can hear sound waves between 20 and 20,000 Hertz, the audio band. Sound, pressure waves, can extend as high as 10 MHz, however above 160 kHz propagation range greatly decreases due to absorption by atmospheric gases, air.
|
Frequency Range | Use | Band |
---|---|---|
0 - 20 Hz | Elephants, Whales | infrasound |
20 - 20,000 Hz | Humans, Animals, Fish, SONAR | audio |
10 - 30 kHz | Rodents | audio - ultrasound |
20 - 75 kHz | Insects | audio - ultrasound |
20 - 160 kHz | Bats, Dolphins | ultrasound |
100 kHz - 2 MHz | Structures Test | ultrasound |
1 - 10 MHz | Medical Applications | ultrasound |
AM radio broadcast electromagnetic waves from 0.5 - 1.6 MHz