Definition of modulation index
: a measure of the degree of frequency modulation expressed numerically for a pure tone modulation as the ratio of the frequency deviation to the frequency of the modulating signal
Start your free trial today and get unlimited access to America's largest dictionary, with:
- More than 250,000 words that aren't in our free dictionary
- Expanded definitions, etymologies, and usage notes
- Advanced search features
- Ad free!
Seen and Heard
What made you want to look up modulation index? Please tell us where you read or heard it (including the quote, if possible).