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Radio frequency (RF) is the oscillation rate of an alternating electric current or voltage or of a magnetic, electric or electromagnetic field or mechanical system in the frequency range from around 20 kHz to around 300 GHz.This is roughly between the upper limit of audio frequencies and the lower limit of infrared frequencies, and also encompasses the microwave range, though other definitions ...
The radio spectrum is the part of the electromagnetic spectrum with frequencies from 3 Hz to 3,000 GHz (3 THz).Electromagnetic waves in this frequency range, called radio waves, are widely used in modern technology, particularly in telecommunication.To prevent interference between different users, the generation and transmission of radio waves is strictly regulated by national laws ...
The invention of radio is a complex and disputed topic that involves many individuals and experiments. This article provides an overview of the history and development of radio technology, from the early discoveries of electromagnetic waves to the modern applications of radio communication. Learn more about the pioneers, controversies and innovations that shaped the radio industry.
The International Telecommunication Union uses an internationally agreed system for classifying radio frequency signals. Each type of radio emission is classified according to its bandwidth, method of modulation, nature of the modulating signal, and type of information transmitted on the carrier signal. It is based on characteristics of the ...
Amateur radio, also known as ham radio, is the use of the radio frequency spectrum for purposes of non-commercial exchange of messages, wireless experimentation, self-training, private recreation, radiosport, contesting, and emergency communications. [1] The term "amateur" is used to specify "a duly authorized person interested in radioelectric ...
Radio navigation. Radio navigation or radionavigation is the application of radio frequencies to determine a position of an object on the Earth, either the vessel or an obstruction. [1] [2] Like radiolocation, it is a type of radiodetermination . The basic principles are measurements from/to electric beacons, especially.
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.
