AM
A radio modulation technique that conveys information by varying the amplitude of a carrier wave. The signal can travel along the ground and reflect off the ionosphere, giving extremely wide coverage, but with narrow bandwidth and poor audio quality. It is suited to broadcast coverage in sparsely populated areas.
Timeline (last 90 days)
Aviation communications use amplitude modulation (AM) technology rather than frequency modulation (FM).
When multiple stations transmit simultaneously, AM signals produce an audible beat phenomenon that allows both parties to detect channel conflicts.
One reason the airband persists in using AM is that its demodulation circuit is relatively simple, resulting in lower receiver complexity and cost.
Envelope detection is the most classic implementation method in AM demodulation, restoring the baseband audio by tracking the amplitude envelope of the modulated signal.
The AM system developed by Doug Lenat in the 1970s rediscovered the concept of prime numbers and Goldbach's conjecture within set theory through heuristic rules.
All Facts (5)
Aviation communications use amplitude modulation (AM) technology rather than frequency modulation (FM).
50%UnverifiedWhen multiple stations transmit simultaneously, AM signals produce an audible beat phenomenon that allows both parties to detect channel conflicts.
50%UnverifiedOne reason the airband persists in using AM is that its demodulation circuit is relatively simple, resulting in lower receiver complexity and cost.
50%UnverifiedEnvelope detection is the most classic implementation method in AM demodulation, restoring the baseband audio by tracking the amplitude envelope of the modulated signal.
50%UnverifiedThe AM system developed by Doug Lenat in the 1970s rediscovered the concept of prime numbers and Goldbach's conjecture within set theory through heuristic rules.
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