Frequency deviation

Frequency deviation

Frequency deviation (Δf) is used in FM radio to describe the maximum instantaneous difference between an FM modulated frequency and the nominal carrier frequency. The term is sometimes mistakenly used as synonymous with frequency drift, which is an unintended offset of an oscillator from its nominal frequency.

The frequency deviation of a radio is of particular importantance in relation to bandwidth, because less deviation means that more channels can fit into the same amount of frequency spectrum. The FM broadcasting range (88-108 MHz) uses a channel spacing of 200 kHz, with a maximum frequency deviation of 75 kHz, leaving a 25 kHz buffer above and below the center frequency to reduce interaction with other channels. [http://hyperphysics.phy-astr.gsu.edu/hbase/audio/radio.html] AM broadcasting uses a channel spacing of 10 kHz, but with amplitude modulation frequency deviation is irrelevant.

FM applications use peak deviations of 75 kHz (200 kHz spacing), 5 kHz (25 kHz spacing), 2.25 kHz (12.5 kHz spacing), and 2 kHz (8.33 kHz spacing). [http://www.rsgb-spectrumforum.org.uk/Papers/VHF/Davos%20C5%20Papers/DV05_C5_17%20SARL%20NBFM.pdf]

See also

* Frequency modulation

References

*Federal Standard 1037C
*MIL-STD-188


Wikimedia Foundation. 2010.

Игры ⚽ Поможем решить контрольную работу

Look at other dictionaries:

  • frequency deviation — dažnio nuokrypis statusas T sritis automatika atitikmenys: angl. frequency departure; frequency deviation vok. Frequenzablage, f; Frequenzabwanderung, f; Frequenzabweichung, f rus. отклонение частоты, n pranc. écart de fréquence, m; dérive de… …   Automatikos terminų žodynas

  • frequency deviation — dažnio nuokrypis statusas T sritis radioelektronika atitikmenys: angl. frequency departure; frequency deviation vok. Frequenzablage, f; Frequenzabwanderung, f; Frequenzabweichung, f rus. отклонение частоты, n pranc. écart de fréquence, m; dérive… …   Radioelektronikos terminų žodynas

  • frequency deviation — dažnio nuokrypis statusas T sritis fizika atitikmenys: angl. frequency deviation vok. Frequenzabweichung, f rus. отклонение частоты, n pranc. déviation de fréquence, f; excursion de fréquence, f …   Fizikos terminų žodynas

  • absolute frequency deviation — absoliutusis dažnio nuokrypis statusas T sritis Standartizacija ir metrologija apibrėžtis Didžiausias skirtumas tarp moduliuotojo dažnio bangos akimirkinio dažnio ir nešlio bangos vidutinio dažnio. atitikmenys: angl. absolute frequency deviation… …   Penkiakalbis aiškinamasis metrologijos terminų žodynas

  • Deviation — may refer to: Deviation (statistics), the difference between the value of an observation and the mean of the population in mathematics and statistics Standard deviation, which is based on the square of the difference Absolute deviation, where the …   Wikipedia

  • Frequency modulation — See also: Amplitude modulation In telecommunications, frequency modulation (FM) conveys information over a carrier wave by varying its frequency (contrast this with amplitude modulation, in which the amplitude of the carrier is varied while its… …   Wikipedia

  • Frequency — For other uses, see Frequency (disambiguation). Three cyclically flashing lights, from lowest frequency (top) to highest frequency (bottom). f is the frequency in hertz (Hz), meaning the number of cycles per second. T is the period in seconds (s) …   Wikipedia

  • Frequency-shift keying — Passband modulation v · d · e Analog modulation AM · …   Wikipedia

  • déviation de fréquence — dažnio nuokrypis statusas T sritis automatika atitikmenys: angl. frequency departure; frequency deviation vok. Frequenzablage, f; Frequenzabwanderung, f; Frequenzabweichung, f rus. отклонение частоты, n pranc. écart de fréquence, m; dérive de… …   Automatikos terminų žodynas

  • déviation de fréquence — dažnio nuokrypis statusas T sritis radioelektronika atitikmenys: angl. frequency departure; frequency deviation vok. Frequenzablage, f; Frequenzabwanderung, f; Frequenzabweichung, f rus. отклонение частоты, n pranc. écart de fréquence, m; dérive… …   Radioelektronikos terminų žodynas

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”