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Frequency modulation (FM) is the encoding of information in either analogue or digital form into a carrier wave by variation of its instantaneous frequency in accordance with an input signal. This is typically accomplished using radio waves. The most typical use is radio broadcasting.
Frequency modulation requires a wider bandwidth than amplitude modulation by an equivalent modulating signal, but this also makes the signal more robust against interference. Frequency modulation is also more robust against simple signal amplitude fading phenomena. As a result, FM was chosen as the modulation standard for high frequency, high fidelity radio transmission: hence the term " FM radio" (although for many years the BBCThe British Broadcasting Corporation BBC is primarily a national publicly-funded broadcaster based in the United Kingdom, which also has some international services. Some of the international services (such as BBC cable TV in America, Canada and elsewhere insisted on calling it "VHF radio", which is quite logical, since commercial FM broadcasting uses a well-known part of the VHF frequency band; in certain countries, expressions referencing the more familiar wavelength notion are still used in place of the somewhat mysterious modulation technique name).
An FM signal can also be used to carry a stereoStereo or stereophony generally refers to dual-channel sound recording and sound reproduction sound that contains data for more than one speaker simultaneously. Compact disc audio and some radio broadcasts are stereo. The purpose of stereo recording is to signal: see FM stereo. However, this is done by using multiplexing and demultiplexing before and after the FM process, and is not part of FM proper. The rest of this article ignores the stereo multiplexing and demultiplexing processed used in "stereo FM", and concentrates on the FM modulation and demodulation process, which is identical in stereo and mono processes.
Before the New YorkNew York is a state in the northeastern United States whose U. postal abbreviation is NY . It is sometimes called New York State when there is need to distinguish it from New York City. History See: History of New York New York was one of the thirteen col section of the Institute of Radio EngineersFollowing several attempts to form a technical organization of wireless practitioners in 1908-1912, the Institute of Radio Engineers (IRE) was finally established in 1912 in New York. Among its founding organizations were the Society of Wireless Telegraph on November 6November 6 is the 310th day of the year (311th in leap years) in the Gregorian Calendar, with 55 days remaining. From September 23, there are 88 days in a fall ( autumn) season. We are considered halfway through fall (autumn) on November 6. Events 1528 Sh, 1935Events January January 1 Italian colonies of Tripoli and Kyrenaika are joined together as Libya January 7 World War II: Italian premier Benito Mussolini and French foreign minister Pierre Laval conclude agreement in which each power undertakes not to oppo, Edwin Armstrong presented his paper "A Method of Reducing Disturbances in Radio Signaling by a System of Frequency Modulation" which first described FM radio.
Analogue-tuning FM receivers inherently exhibit a phenomenon called capture, where the tuner's frequency drift or lack of selectivity will cause one station or signal to be suddenly overtaken by another on an adjacent channel. This is generally not the case with digital tuners, which use a PLL circuit to prevent this.