The main difference between AM (Amplitude Modulation) and FM (Frequency Modulation) radio waves lies in how the information (audio signal) is encoded onto the carrier wave:
- AM (Amplitude Modulation):
- The strength or amplitude of the radio wave changes according to the sound information.
- The frequency remains constant while the amplitude varies.
- AM signals can travel longer distances, especially at night, but are more prone to noise and interference because noise affects amplitude.
- FM (Frequency Modulation):
- The frequency of the radio wave changes in line with the sound information.
- The amplitude stays constant while the frequency varies.
- FM provides better sound quality with less noise and interference but usually has a shorter range than AM.
In summary, AM changes the height of the wave to carry sound, while FM changes the wave’s frequency.