what is the necessity of modulation?
modulation smply means to increase the frequency of the signal,for better transmission.
modulation is important due to following reasons:
- height of antenna:for better transmission the height of antenna should be quarter half of the wavelength of wave to be transmitted.so,frequency is increased(wavelength decreased) to make it practically possible.
- power radiated:the power is inversly proportional to the height of antenna or wavelenth.so frequency is increased.
- need of bandwidth:suppose many people are talking at the same time,we just cant make out the difference who is talking what,so bandwidth is provided to each wave and it is done over high frequency to save the quality of signal.
Basically the mean of modulation is that to inclrease the frequency of message signal for long distance .The first and major importance of modulation is to achive long distance communication,
If we transmit a message singnal directly then it would attain a certain and short distance,
to achive long distance communication we will add a high frequncy signal with the message singnal and finally the frequncy of message signal will increases and now it will be possible to achive long distance communication.