What type of modulation leads to the generation of sideband frequencies?

Amplitude modulation (AM) leads to the generation of sideband frequencies because it involves varying the amplitude of a carrier wave according to the amplitude of the audio or information signal being transmitted. When this modulation occurs, the process creates new frequency components in the output signal: the carrier frequency itself and two additional frequencies, which are known as sidebands.

These sidebands are positioned at frequencies above and below the carrier frequency. Specifically, in AM, the upper sideband is the carrier frequency plus the modulating signal frequency, while the lower sideband is the carrier frequency minus the modulating signal frequency. This unique aspect of amplitude modulation allows it to effectively transmit information over long distances, as the sidebands carry the actual audio or data content.

In contrast, pulse modulation, digital modulation, and polar modulation do not inherently produce sidebands in the same manner as amplitude modulation. Each of those methods operates under different principles and does not result in the creation of side frequencies that typify the amplitude modulation technique.