Frequency Modulation |
Amplitude Modulation |
|
1) The
amplitude of FM signal is constant and in depth of Modulation. |
1) Amplitude of AM signal varies depending on Modulation index. |
|
2) It
requires much wider channel (7-15 times) as compared to AM |
2) Band width, is very small, which is one of the biggest
disadvantages. |
|
3) Transmitters
are complex and hence expensive |
3) Relatively simple and cheap |
|
4) Area
of reception is small since it is limited to line of sight |
4) Area of reception is large |
|
5) Noise
can be easily minimized. Amplitude variations can be eliminated by using
limiter. |
5) More susceptible to noise, interference & low signal to noise
ratio. Difficult to eliminate effects of noise. |
|
6) Average
power in frequency modulated wave is same as contained in un-modulated wave. |
6) Average power in modulated wave is greater than carrier power.
This added power is provided by modulating source. |
|
7) No
restriction is placed on modulated index. |
7) Maximum modulation index is 1 otherwise over modulation would
result in distortion. |
|
8) Possible
to operate several independent transmitters on same frequency. |
8) Not possible to operate out interference. |
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