\[m=\frac{A_m}{A_c}\]
Variables
mmodulation index
Ammodulating signal amplitude
Accarrier signal amplitude
Description
What is this formula?
The modulation index is a dimensionless parameter that measures the degree of modulation applied to a carrier signal in amplitude modulation (AM) systems. It represents the ratio between the amplitude of the modulating signal and the amplitude of the carrier.
When to use it
Use this formula when analyzing or designing AM communication systems, radio transmitters, broadcast equipment, and laboratory modulation experiments.
Example
An AM transmitter uses a carrier amplitude of 10 V and a modulating signal amplitude of 6 V.
Formula:
m = Am/Ac
Substitution:
m = 6/10
Result:
m = 0.6
The modulation index is 0.6 or 60%.
Applications
AM radio broadcasting, communication system design, transmitter testing, signal quality analysis, telecommunications education, and RF laboratory measurements.