AM VS FM Have you ever wondered why the FM radio in your car has higher sound quality than AM radio? But why does AM radio have a longer range than FM radio wave? The following excerpt will cover wave theory, wave carriers, and modulation to provide an in-depth understanding of am and fm waves and the concepts surrounding them. WAVE THEORY: Wave theory states that: waves transfer energy from one point to another; however they do so without transferring matter. They consist of disturbances within the wave, which is what creates the two different types of waves: longitudinal and transverse. A transverse wave is a wave in which the vibrations or particles of the medium travel perpendicular to the direction in which the wave travels. example: if a buoy were placed in the middle of the ocean where multiple groups of waves occur, the buoy would only move up and down, yet the groups of waves continue to move forward towards the shore; the same principle applies to sound waves, indicating that the particles of the medium travel perpendicular to the direction of the wave. Refer to Figure 2 for a visual understanding. The height of the crest from equilibrium is known as the amplitude. A longitudinal wave on the other hand is where the particles of the medium move in the same direction as the wave. Energy is transmitted along air molecules through the longitudinal vibrations of a longitudinal wave. This process continues throughout the wave and t...... middle of paper ....... To calculate the bandwidth produced by an FM wave, the sum of the modulating frequency is doubled, as is the frequency deviation. For example, if the frequency deviation is 75kHz and the frequency of the modulating signal is 15kHz, the bandwidth required to transmit the signal must be 180kHz. Frequency deviation refers to the maximum instantaneous difference between an FM modulated frequency and the carrier frequency. As stated in "AM vs FM", each type of modulation has its pros and cons. Although AM has the ability to have multiple channels available within a given range, the overall sound quality is not particularly good, due to the sound being stored in the amplitude part of the wave; and obviously this is what is being modulated. Therefore, FM radio broadcasts are better overall due to the higher quality of sound it produces.