What term describes the ratio of the peak frequency deviation of a signal to the modulating frequency?

The term that describes the ratio of the peak frequency deviation of a signal to the modulating frequency is known as the modulation index. This concept is particularly important in frequency modulation (FM), where the modulation index provides a measure of how much the frequency of the carrier wave is varied in relation to the amplitude of the input signal.

The modulation index helps determine the bandwidth of the FM signal, contributing to how much information can be transmitted effectively. A higher modulation index typically results in a greater frequency deviation, leading to a wider bandwidth, which is crucial in ensuring that multiple signals can occupy the same frequency spectrum without interference.

Understanding the modulation index is essential for designing and analyzing communication systems, as it affects both the quality of signal transmission and the efficiency of frequency use.