What is is radio transmission?
In the communication engineering transmission means sending some data from one end to another. So radio transmission definition can be written as the process of transmission of data using radio waves. Another name of radio wave is electromagnetic wave.
Radio transmission can be done using many frequency bands. Each band has some pros and cons. The following table will give you an idea of the frequency ranges of different frequency bands.
| Class of Radio Waves | Frequency Range |
| Extremely low frequency (ELF) | 3 Hz – 30 Hz |
| Super low frequency (SLF) | 30 Hz – 300 Hz |
| Ultra low frequency (ULF) | 300 Hz – 3 kHz |
| Very low frequency (VLF) | 3 kHz – 30 kHz |
| Low frequency (LF) | 30 kHz – 300 kHz |
| Medium frequency (MF) | 300 kHz – 3 Mhz |
| High frequency (HF) | 3 MHz – 30 MHz |
| Very high frequency (VHF) | 30 MHz – 300 MHz |
| Ultra high frequency (UHF) | 300 MHz – 3 GHz |
| Super high frequency (SHF) | 3 GHz – 30 GHz |
| Extremely high frequency (EHF) | 30 GHz – 300 GHz |
This radio wave range is described by the two things frequency (f) and wavelength (λ). Both of these parameters are inversely proportional to each other. Relationship between these two is given below
f = c / λ
Where “c” is the speed of light in vacuum which is equal to 2.998 x 10^8 m/s.
What is Extremely Low Frequency (ELF)?
Extremely low frequency range Is from 3 Hz to 30 Hz with wavelengths from 100,000 to 10,000 km.
Who uses extremely low frequency?
Due to the large size of the wavelength, It is very difficult to build antenna (for every application) which can support big wavelength. That is why it is used in very few applications. They have the ability to penetrate into the sea water that is why submarines use ELF.
What is Super Low Frequency (SLF)?
It ranges from 30 Hz to 300 Hz with wavelengths from 10,000 km to 1000 km.
Who uses super low frequency?
Similar to ELF it is very difficult to use huge antennas at every place that can support SLF. But currently some Naval services are using SLF to communicate with their submarines. You can observe this frequency range also includes AC power grid frequency i.e 50Hz and 60Hz.
What is Ultra low frequency (ULF)?
From 300 Hz to 3 kHz frequency range is designated as ULF. The wavelength ranges from 1000 km to 100 km respectively.
Who uses ultra low frequency?
Military services use this for defense purposes. Earth mode communication with the Ultra low frequency range had been used for some time. In earth mode communication a ULF signal is sent through the ground. Receiver at a small distance receives it as a very weak electric current.
What is Very Low Frequency (LF)?
This frequency band comes in the range of 3 kHz to 30 kHz with wavelengths of 100 km to 10 km respectively.
Who uses very low frequency?
Some radio navigation services used VLF. In the 20th century, ships and air crafts used VLF transmitters to find out their geographical location by comparing the phase angle of the wave received from the transmitter. In addition to this VLF radio telegraphy stations were used to transmit textual data.
These waves also have the ability to penetrate into the water up to 120 feet so NAVAL services use VLF to communicate with submarines.
What is Low frequency (LF)?
Its wavelength ranges from 10 km to 1 km. The responding frequency range is 30 kHz to 300 kHz respectively. Because smallest wavelength is 1 km that is why this range is also known as kilometer band.
Who uses low frequency?
Because of the size of their wavelengths, this frequency range is suitable for long distance communication in some parts of the world. LF band is used as AM broadcasting.
What is Medium frequency (MF)?
Radio waves spectrum with the range of 300 kHz o 3 MHz is designated the name medium frequency band. Its wavelength ranges from 1000 m to 100 m respectively.
Who uses medium frequency?
AM broadcast stations use MF with a frequency range of 526.5 kHz to 1606.5 kHz. Another application is Maritime Services which use MF to communicate between ship and the shore.
What is High Frequency (HF)?
International Telecommunication Union (ITU) designated the frequency band between 3 MHz to 30 MHz as high frequency band. In this band minimum wavelength is 10 m whereas maximum wavelength is 100 meter.
Who uses high frequency?
These waves can be reflected back from the ionosphere towards the earth so long distance communication can be done via HF. Many military and government organisations use this frequency range. Other uses are aviation air-to-ground communication, shortwave radio communication, ship-to-ship and ship-to-shore maritime services.
What is very high frequency (VHF)?
VHF frequency range is from 30 MHz to 300 MHz and wavelengths are from 10 m to 1 m.
Who uses very high frequency?
VHF band is used in many applications including FM broadcast, mobile communication, cable TV network, long distance data communication services and air traffic control.
What is ultra high frequency (UHF)?
UHF frequency range is from 300 MHz to 3 GHz. The wavelength of UHF band is as small as one tenth of a meter.
Who uses ultra high frequency?
Many modern technologies of today like GPS, satellite communication, Wi-Fi networks, WiMAX, Bluetooth and many more technologies use UHF frequency band.
What is super high frequency (SHF)?
This radio waves spectrum ranges from 3 GHz to 30 GHz. This might also use to call centimeter band because wavelength range is from 1 to 10 centimeter. SHF band is also known as microwave band. These beams are highly directed so they are used in point-to-point communication.
Who uses super high frequency?
As the name “Microwave” suggests these are used in microwave ovens. Other uses are satellite communication, radar communication. Many research organisations are working to use microwaves as an alternative of UHF to use in mobile communication but directed beam is the prime concern.
What is extremely high frequency (EHF)?
The frequency band from 30 GHz to 300 GHz is designated as extremely high frequency band. The wavelength is very small about 1 millimeter. This is why it is also known as millimeter wave (mmWave) spectrum.
Who uses extremely high frequency?
Because of very small wavelength these waves get very high attenuation from the atmospheric particles. But they are used in some applications For example radio astronomy and remote sensing. IEEE 802.11ad Wi-Fi standard uses 60 gigahertz frequency to achieve data rate of 7 gigabits per second.
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