Microwaves are a type of electromagnetic radiation, as are radio waves, ultraviolet radiation, X-rays and gamma-rays. Microwaves have a range of applications, including communications, radar and, perhaps.
Microwave is a form of electromagnetic radiation with wavelength ranging from about one meter to one millimeter corresponding to frequencies between 300 MHz and 300 GHz respectively. Different sources define different frequency ranges as microwaves; the above broad definition includes both UHF and EHF(millimeter wave)) bands. A more common definition in radio-frequency is the range between 1 and 100 GHz (wavelengths between 0.3 m and 3 mm). In all cases, microwaves include the entire SHF band (3 to 30 GHz, or 10 to 1 cm) at minimum. Frequencies in the microwave range are often referred to by their IEEE radar band designations: S, C, X, K, K, or K, band
The apertures of the dishes are covered by plastic sheets (radomes) to keep out moisture.
Ultra high frequency (UHF)
Ultra high frequency (UHF) refers to the band of electromagnetic radiation with a radio frequency range between 300 MHz and 3 GHz (3000 MHz). This band is also known as the decimeter band, with a wavelength ranging from 1 m to 1 dm. The UHF radiations are least affected by environmental factors, that is why they are most commonly used for TV and radio transmission and channel broadcasting. They have strong directivity, but, at the same time, the receiving error increases.
Ultra high frequency (UHF) is the ITU designation for radio frequencies in the range between 300 megahertz (MHz) and 3 gigahertz (GHz), also known as the decimetre band as the wavelengths range from one meter to one tenth of a meter (one decimeter). Radio waves with frequencies above the UHF band fall into the super-high frequency (SHF) or microwave frequency range. Lower frequency signals fall into the VHF (very high frequency) or lower bands. UHF radio waves propagate mainly by line of sight; they are blocked by hills and large buildings although the transmission through building walls is strong enough for indoor reception. They are used for television broadcasting, cell phones, satellite communication including GPS, personal radio services including Wi-Fi and Bluetooth, walkie-talkies, cordless phones,and numerous other applications
|Ultra high frequency|
|Ultra high frequency (ITU)|
|Frequency range||300 MHz to 3 GHz|
|Wavelength range||1 m to 1 dm|
|Related bands||B / C / D / E bands (NATO)UHF and L / S bands (IEEE)|
|Ultra high frequency (IEEE)|
|Frequency range||300 MHz to 3 GHz|
|Wavelength range||1 m to 3 dm|
|Related bands||UHF (ITU)B / C bands (NATO)|
Extremely high frequency (EHF)
Extremely high frequency (EHF) is the International Telecommunication Union (ITU) designation for the band of radio frequencies in the electromagnetic spectrum from 30 to 300 (GHz). It lies between the super high frequency band and the far infrared band, the lower part of which is the terahertz band, Radio waves in this band have wavelengths from ten to one millimetre, so it is also called the millimetre band and radiation in this band is called millimetre waves, sometimes abbreviated MMW or mmWave. Millimetre-length electromagnetic waves were first investigated by Indian physicist Jagdish Chandra Bose during 1894–1896, when he reached up to 60 GHz in his experiments
|Extremely high frequency|
|Extremely high frequency (ITU)|
|Frequency range||30 to 300 GHz|
|Wavelength range||10–1 mm|
|Related bands||K / L / M (NATO)K / V / W / mm (IEEE)|
|Millimetre band (IEEE)|
|Frequency range||110 to 300 GHz|
|Wavelength range||2.73 to 1 mm|
|Related bands||EHF (IEEE)|
Radio-frequency (RF) engineering
Radio-frequency (RF) engineering is a subset of electronic engineering involving the application of transmission line, waveguide, antenna and electromagnetic field principles to the design and application of devices that produce or utilize signals within the radio band, the frequency range of about 20 KHz up to 300 GHz.
Super high frequency (SHF)
Super high frequency (SHF) is the ITU designation for radio frequencies (RF) in the range between 3 and 30 (GHz). This band of frequencies is also known as the centimetre band or centimetre wave as the wavelengths range from one to ten centimetres. These frequencies fall within the microwave band, so radio waves with these frequencies are called microwaves. The small wavelength of microwaves allows them to be directed in narrow beams by aperture antennas such as parabolic dishes and horn antennas, so they are used for point to point communication and data links and for radar. This frequency range is used for most radar transmitters, wireless LANs, satellite communication, microwave radio relay links, and numerous short range terrestrial data links. They are also used for heating in industrial microwave heating, medical diathermy, microwave hyperthermy to treat cancer, and to cook food in microwave ovens.