What does AM stand for in modulation terminology?

What does AM stand for in modulation terminology?

• A. Amplitude Modulation
• B. Analog Modulation
• C. Angular Modulation
• D. Amplitude Modulator

Answer: (A)

Amplitude modulation is the idea that information is carried by changing how tall the carrier wave is, while the carrier’s frequency stays constant. In AM, the instantaneous amplitude of the carrier follows the signal you want to send, so the envelope of the modulated wave mirrors the information signal. A receiver using an envelope detector can then extract that information from the varying amplitude. That’s why the phrase stands for Amplitude Modulation. It’s not simply a general term like Analog Modulation or a device name like Amplitude Modulator, and it isn’t about changing the angle (phase) or frequency of the carrier, which are other forms of modulation. If you hear about envelope-following detection and broadcast radio, you’re in the realm of AM.

Amplitude modulation is the idea that information is carried by changing how tall the carrier wave is, while the carrier’s frequency stays constant. In AM, the instantaneous amplitude of the carrier follows the signal you want to send, so the envelope of the modulated wave mirrors the information signal. A receiver using an envelope detector can then extract that information from the varying amplitude.

That’s why the phrase stands for Amplitude Modulation. It’s not simply a general term like Analog Modulation or a device name like Amplitude Modulator, and it isn’t about changing the angle (phase) or frequency of the carrier, which are other forms of modulation. If you hear about envelope-following detection and broadcast radio, you’re in the realm of AM.