Amplitude modulation

Definition

Amplitude modulation (AM) is a technique used to encode information onto a carrier wave by varying its amplitude. This method is commonly used in radio broadcasting.

5 Must Know Facts For Your Next Test

1. AM works by varying the amplitude of the carrier wave while keeping its frequency constant.
2. The carrier wave in AM has a much higher frequency than the modulating signal.
3. An AM signal can be demodulated using an envelope detector or synchronous demodulation.
4. AM signals are prone to noise and interference because amplitude variations can be easily affected by external factors.
5. Despite being more susceptible to noise, AM is still widely used in commercial radio broadcasting due to its simplicity and cost-effectiveness.

Review Questions

• What aspect of the carrier wave is varied in amplitude modulation?
• Why are AM signals more susceptible to noise compared to FM signals?
• What is one common use of amplitude modulation in everyday life?

Related terms

Frequency Modulation (FM): A technique where the frequency of the carrier wave is varied in proportion to the modulating signal.

Carrier Wave: A high-frequency electromagnetic wave that can be modulated with a data-bearing signal for transmission.

Demodulation: \text{The process of extracting the original information-carrying signal from a modulated carrier wave.}