Capture effect

Capture effect

In telecommunication, the capture effect, or FM capture effect, is a phenomenon associated with FM reception in which only the stronger of two signals at, or near, the same frequency will be demodulated.

The capture effect is defined as the complete suppression of the weaker signal at the receiver limiter (if it has one) where the weaker signal is not amplified, but attenuated. When both signals are nearly equal in strength, or are fading independently, the receiver may switch from one to the other and exhibit picket fencing.

Amplitude Modulation, or AM radio, transmission is not subject to this effect. This is one reason that the aviation industry, and others, have chosen to use AM for communications rather than FM, allowing multiple signals to be broadcast on the same channel. Similar phenomena to the capture effect are described in AM when offset carriers of different strengths are present in the passband of a receiver. For example, the aviation glideslope vertical guidance clearance beam is sometimes described as a "capture effect" system, even though it operates using AM signals.

For digital modulation schemes it has been shown that for properly implemented OOK/ASK systems, co-channel rejection can be better than for FSK systems.

Notes and References

Source: from Federal Standard 1037C and from MIL-STD-188


Wikimedia Foundation. 2010.

Игры ⚽ Поможем решить контрольную работу

Look at other dictionaries:

  • Channel capture effect — The channel capture effect is a phenomenon where one user of a shared medium captures the medium for a significant time. During this period (usually 16 frames)[clarification needed], other users are denied use of the medium. This effect was first …   Wikipedia

  • capture — [kap′chər] n. [Fr < L captura < captus: see CAPTIVE] 1. a taking or being taken by force, surprise, or skill, as enemy troops, an opponent s piece in chess, etc. 2. that which is thus taken or seized; specif., a prize or booty in war 3. the …   English World dictionary

  • Capture of Shusha — Infobox Military Conflict conflict=Capture of Shusha caption= Gagik Avsharyan s restored T 72 tank stands as a memorial commemorating the capture of Shusha. partof=the Nagorno Karabakh War place=Shusha, town in Nagorno Karabakh date=May 8, 1992 – …   Wikipedia

  • Capture of Cyane — HMS Cyane was a British warship captured by the USS Constitution on 20 February 1815 during the War of 1812. Cyane was sailing in company with HMS Levant .The Capture of HMS CyaneHMS Cyane was a British 6th rate 22 gun frigate build ship in… …   Wikipedia

  • Capture of USS President — Infobox Military Conflict conflict=Capture of USS President caption= partof=the War of 1812 date=December 13, 1814 place=outside of New York Harbor, New York, New York result=British victory combatant1=flag|Great Britain combatant2=flag|United… …   Wikipedia

  • Effect of the Siege of Leningrad on the city — Timeline of the Siege of Leningrad 1941 *June 22: Operation Barbarossa begins. *June 29: Evacuation of children and women from Leningrad starts. *June–July: Over 300 thousand civilian refugees from Pskov and Novgorod manage to escape from the… …   Wikipedia

  • Races of the Mass Effect universe — This article is about the fictional races found within the Mass Effect universe. These races are explored in the novels Mass Effect: Revelation and Mass Effect: Ascension, and the video games Mass Effect, Mass Effect Galaxy, and Mass Effect 2.… …   Wikipedia

  • Characters of the Mass Effect universe — This article describes notable characters who appear in the Mass Effect fictional universe. These characters are explored in the novels Mass Effect: Revelation, Mass Effect: Ascension, Mass Effect: Retribution, and Mass Effect: Deception; the… …   Wikipedia

  • Mass Effect (video game) — Mass Effect Developer(s) BioWare (Xbox 360) Demiurge Studios (Microsoft Windows[1] …   Wikipedia

  • Stream capture — Stream capture, river capture, or stream piracy is a geomorphological phenomenon occurring when a stream or river drainage system or watershed is diverted from its own bed, and flows instead down the bed of a neighbouring stream. This can happen… …   Wikipedia

Share the article and excerpts

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