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Emission (radiocommunications)
Emission is the radiation or radio signal produced or emitted by a radio transmitting station.ITU Radio Regulations Radio regulation refers to the regulation and licensing of radio in international law, by individual governments, and by municipalities. International regulation The International Telecommunication Union (ITU) is a specialized agency of the Unit ..., Volume 1, Article 1, Provision No. 1.138; Edition of 2008 References Radio {{radio-comm-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiation
In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or a material medium. This includes: * ''electromagnetic radiation'' consisting of photons, such as radio waves, microwaves, infrared, visible light, ultraviolet, x-rays, and Gamma ray, gamma radiation (γ) * ''particle radiation'' consisting of particles of non-zero rest energy, such as alpha radiation (α), beta radiation (β), proton radiation and neutron radiation * ''acoustics, acoustic radiation'', such as ultrasound, sound, and seismic waves, all dependent on a physical transmission medium * ''gravitational radiation'', in the form of gravitational waves, ripples in spacetime Radiation is often categorized as either ''ionizing radiation, ionizing'' or ''non-ionizing radiation, non-ionizing'' depending on the energy of the radiated particles. Ionizing radiation carries more than 10 electron volt, electron volts (eV), which is enough to ionize atoms and molecul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Signal
Radio waves (formerly called Hertzian waves) are a type of electromagnetic radiation with the lowest frequencies and the longest wavelengths in the electromagnetic spectrum, typically with frequencies below 300 gigahertz (GHz) and wavelengths greater than , about the diameter of a grain of rice. Radio waves with frequencies above about 1 GHz and wavelengths shorter than 30 centimeters are called microwaves. Like all electromagnetic waves, radio waves in vacuum travel at the speed of light, and in the Earth's atmosphere at a slightly lower speed. Radio waves are generated by charged particles undergoing acceleration, such as time-varying electric currents. Naturally occurring radio waves are emitted by lightning and astronomical objects, and are part of the blackbody radiation emitted by all warm objects. Radio waves are generated artificially by an electronic device called a transmitter, which is connected to an antenna, which radiates the waves. They are received ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Station
Radio broadcasting is the broadcasting of audio (sound), sometimes with related metadata, by radio waves to radio receivers belonging to a public audience. In terrestrial radio broadcasting the radio waves are broadcast by a land-based radio station, while in '' satellite radio'' the radio waves are broadcast by a satellite in Earth orbit. To receive the content the listener must have a broadcast radio receiver (''radio''). Stations are often affiliated with a radio network that provides content in a common radio format, either in broadcast syndication or simulcast, or both. The encoding of a radio broadcast depends on whether it uses an analog or digital signal. Analog radio broadcasts use one of two types of radio wave modulation: amplitude modulation for AM radio, or frequency modulation for FM radio. Newer, digital radio stations transmit in several different digital audio standards, such as DAB (Digital Audio Broadcasting), HD radio, or DRM ( Digital Ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Regulations
Radio regulation refers to the regulation and licensing of radio in international law, by individual governments, and by municipalities. International regulation The International Telecommunication Union (ITU) is a specialized agency of the United Nations (UN) that is responsible for issues that concern information and communication technologies. ''ITU Radio Regulations'' are the set of ITU's regulations governing electromagnetic spectrum from 9 kHz to 275 GHz. The reasons are that the radio waves spectrum is on the one hand considered to be a limited natural resource, on the other side some radio waves are able to propagate on considerable distances and interfere with radio services abroad. Government regulation United States In the United States, radio is regulated by the Federal Communications Commission The Federal Communications Commission (FCC) is an independent agency of the United States government that regulates communications by radio, television, wir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
