What is Modulation?
The process of changing some characteristics like Amplitude, Frequency and Phase of a career wave in accordance with the intensity of the signal is called as Modulation.
Why Modulation Needed?
The necessary basic reasons for the modulation is:
- Operating range
- Practical antenna length
- Wireless communication
Therea are different types of modulations which are more necessary for the communicationn system. These are:
(A) Amplitude MOdulation
(B) Frequency Modulation
(C) Phase Modulation
(A) Amplitude Modulation:
It is the change of high frequency career wave in accordance with the intensity of signal, which is called as Amplitude modulation.
In this modulation the frequency of the modulated wave remains constant.
Limitations of Amplitude Modulation:
(i) Small operating range
(ii) Lack of audio quality
(iii) Low frequency
(iv) Noise reception
(B) Frequency Modulation:
When the frequency of the career wave is changed in accordance with the intensity of the signal, it is called frequency modulation.
(i) High frequency reception
(ii) High frequency transmission
(iii) Large operating system
(iv) Noiseless reception
(v) It is used nfor the streo sound transmission.
(i) Frequency Modulation is more extensive as compared to Amplitude Modulation.
(ii) Frequency Modulation reception is limited to line of sight.
(iii) High wider band is required i.e. 7 to 8 times more as compared to Amplitude Modulation.
(C) Phase Modulation:
When the phase angle of the career wave is changed in accordance with the modulationg signal, the resultant wave is called as Phase Modulation.