Comparison of FM and AM Systems

FM and AM are two basic modulation techniques used in communication systems. Angle modulation, which includes both frequency modulation (FM) and phase modulation (PM), is a type of modulation that is widely used in modern communication systems. Here are some key differences between FM and AM, as well as advantages of angle modulation:

1. Bandwidth: FM signals have a much wider bandwidth compared to AM signals. This is because the frequency deviation in FM is proportional to the amplitude of the modulating signal, resulting in a much larger frequency range than the small sidebands produced by AM. In general, FM signals require more bandwidth to transmit than AM signals.

2. Noise Immunity: FM signals are generally more immune to noise and interference than AM signals. This is because the amplitude of the FM signal is constant, while the frequency varies with the modulating signal. As a result, FM signals are less affected by changes in signal amplitude due to noise or interference.

3. Signal-to-Noise Ratio: FM signals have a higher signal-to-noise ratio (SNR) compared to AM signals. This is because FM signals can be demodulated using a narrowband filter, which can remove most of the noise and interference outside the frequency band of the signal.

4. Modulation Depth: The modulation depth of FM signals is much smaller than that of AM signals. This is because FM signals are more sensitive to changes in the frequency of the modulating signal, while AM signals are more sensitive to changes in the amplitude of the modulating signal.

Overall, angle modulation offers several advantages over traditional AM modulation, including better noise immunity, higher SNR, and more efficient use of bandwidth. FM is particularly well-suited for high-fidelity audio transmission, while PM is commonly used in digital communication systems.

Comparison of FM and AM Systems