Frequency Modulation

In telecommunications and signal processing, frequency modulation (FM) conveys information over a carrier wave by varying its instantaneous frequency. This contrasts with amplitude modulation, in which the amplitude of the carrier is varied while its frequency remains constant. In analog applications, the difference between the instantaneous and the base frequency of the carrier is not directly proportional to the instantaneous value of the input-signal amplitude but it is proportional to frequency. Digital data can be sent by shifting the carrier's frequency among a range of settings, a technique known as frequency-shift keying (FSK). FSK is widely used in data and fax modems, and can be used to send Morse code. Radioteletype also uses FSK. Frequency modulation is also used in telemetry, radar, seismic prospecting and newborn EEG seizure monitoring. Frequency modulation is known as phase modulation when the carrier phase modulation is the time integral of the FM signal. FM is widely used for broadcasting music and speech, two-way radio systems, magnetic tape-recording systems and some video-transmission systems. In radio systems, frequency modulation with sufficient bandwidth provides an advantage in cancelling naturally-occurring noise.

Read more about Frequency ModulationTheory, Noise Reduction

Other articles related to "frequency modulation, modulation, frequency":

Frequency Modulation - Applications - Radio
... (1890–1954) was an American electrical engineer who invented wideband frequency modulation (FM) radio ... "A Method of Reducing Disturbances in Radio Signaling by a System of Frequency Modulation", (which first described FM radio) before the New York section of the Institute of Radio Engineers on November 6, 1935 ... (WFM) requires a wider signal bandwidth than amplitude modulation by an equivalent modulating signal this also makes the signal more robust against noise and interference ...
Allan Variance - Confidence Intervals and Equivalent Degrees of Freedom - Effective Degrees of Freedom
... to be Allan variance degrees of freedom Noise type degrees of freedom white phase modulation (WPM) flicker phase modulation (FPM) white frequency modulation (WFM) flicker frequency modulation (FFM) random ...
Armstrong Phase Modulator
... Armstrong patented a method for generating frequency modulation of radio signals ... shifts this signal, and then reinserts the carrier to produce a frequency modulated signal ... Frequency modulation generates high quality audio and greatly reduces the amount of noise on the channel when compared with amplitude modulation ...
Saturn V Instrument Unit - Subsystems - Radio Communications - Measuring and Telemetry
... velocity, flow rate, position, pressure, temperature, voltage, current, frequency, and others ... Both frequency sharing and time sharing multiplexing techniques were used to accomplish this ... The two modulation techniques used were pulse code modulation/frequency modulation (PCM/FM) and frequency modulation/frequency modulation (FM/FM) ...
Angle Modulation
... Angle modulation is a class of analog modulation ... Angle Modulation is modulation in which the angle of a sine-wave carrier is varied by a modulating wave ... Frequency Modulation (FM) and Phase Modulation (PM) are two types of angle modulation ...

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