What does amplitude modulation in a waveform produce in the spectrum?

Amplitude modulation (AM) occurs when the amplitude of a waveform is varied in accordance with the characteristics of a message signal. In the context of the spectrum, these variations create additional frequencies known as sidebands.

When a carrier wave is modulated, two sidebands are produced: the upper sideband and the lower sideband. These sidebands are located at frequencies above and below the carrier frequency, respectively. The spacing of these sidebands from the carrier frequency corresponds to the frequency components of the modulating signal.

For example, if a carrier frequency is modulated by a lower frequency signal, the upper sideband will be at a frequency equal to the carrier frequency plus the modulating frequency, while the lower sideband will be at the carrier frequency minus the modulating frequency. These sidebands effectively convey the information from the modulating signal and are crucial for demodulation in communication systems.

Through this mechanism, amplitude modulation effectively utilizes and occupies a broader bandwidth than just the carrier frequency alone, allowing for the transmission of complex information over radio waves and other communication mediums.