electronics The field of electronics is a branch of physics and electrical engineering that deals with the emission, behaviour and effects of electrons using electronic devices. Electronics uses active devices to control electron flow by amplification ...

, a synchronous detector is a device that recovers information from a modulated signal by mixing the signal with a replica of the unmodulated carrier. This can be locally generated at the receiver using a

phase-locked loop A phase-locked loop or phase lock loop (PLL) is a control system that generates an output signal whose phase is related to the phase of an input signal. There are several different types; the simplest is an electronic circuit consisting of a ...

or other techniques. Synchronous detection preserves any phase information originally present in the modulating signal. With the exception of

SECAM SECAM, also written SÉCAM (, ''Séquentiel de couleur à mémoire'', French for ''color sequential with memory''), is an analog color television system that was used in France, some parts of Europe and Africa, and Russia. It was one of th ...

receivers, synchronous detection is a necessary component of any analog

color television Color television or Colour television is a television transmission technology that includes color information for the picture, so the video image can be displayed in color on the television set. It improves on the monochrome or black-and-white t ...

receiver, where it allows recovery of the phase information that conveys hue.Donald G. Fink (ed.)., ''Electronics Engineers' Handbook'', McGraw Hill, 1975 page 20-57 Synchronous detectors are also found in some

shortwave radio Shortwave radio is radio transmission using shortwave (SW) radio frequencies. There is no official definition of the band, but the range always includes all of the high frequency band (HF), which extends from 3 to 30 MHz (100 to 10 me ...

receivers used for audio signals, where they provide better performance on signals that may be affected by

fading In wireless communications, fading is variation of the attenuation of a signal with various variables. These variables include time, geographical position, and radio frequency. Fading is often modeled as a random process. A fading channel is a ...

References

{{technology-stub Electronic engineering

See also

References