Question

Which of the following is not a type of modulation index ?

• A. Amplitude modulation index
• B. Frequency modulation index
• C. Phase modulation index
• D. Carrier amplitude modulation index

Answer 1

The correct option is D Carrier amplitude modulation index

There are only three types of modulation Index :

1) Amplitude Modulation Index - AM modulation index is the measure based on ratio of the modulation excursion of the RF signal to the level of the

unmodulated carrier .

h = M/A

h= amplitude modulation index

M = modulation amplitude

A =carrier amplitude

2) Frequency Modulation - FM is the encoding of information in a carrier wave by varying the instantaneous frequency of wave .

3) Phase Modulation - Phase modulation (PM) is a modulation pattern for conditioning communication signals for transmission .