The following table gives the comparison in AM and FM.
| S.NO | AMPLITUDE MODULATION | FREQUENCY MODULATION |
| 1. | Band width is very small which is one of the biggest advantage | It requires much wider channel ( 7 to 15 times ) as compared to AM. |
| 2. | The amplitude of AM signal varies depending on modulation index. | The amplitude of FM signal is constant and independent of depth of the modulation. |
| 3. | Area of reception is large | The are of reception is small since it is limited to line of sight. |
| 4. | Transmitters are relatively simple & cheap. | Transmitters are complex and hence expensive. |
| 5. | The average power in modulated wave is greater than carrier power. This added power is provided by modulating source. | The average power in frequency modulated wave is same as contained in un-modulated wave. |
| 6. | More susceptible to noise interference and has low signal to noise ratio, it is more difficult to eliminate effects of noise. | Noise can be easily minimized amplitude variations can be eliminated by using limiter. |
| 7. | it is not possible to operate without interference. | it is possible to operate several independent transmitters on same frequency. |
| 8. | The maximum value of modulation index = 1, other wise over-modulation would result in distortions. | No restriction is placed on modulation index. |
This entry was posted
on Monday, June 1, 2009
at 6/01/2009 12:01:00 AM
and is filed under
AM,
amplitude,
BANDWIDTH,
communication,
communication system,
comparison in AM and FM,
FM,
frequency,
modulation,
signal,
transmitter,
TRANSMITTERS
. You can follow any responses to this entry through the
comments feed
.
