Amplitude Modulation

Amplitude Modulation

. Speech and music are transmitted hundreds of kilometers away by a radio transmitter. the picture
taken by the TV camera is sent many kilometers away to viewers. in all these cases, the career of
speech or picture is a high-frequency radio wave. the information is superposed on the radio wave.
it is carried along with it to the destination.

. Modulation is the process of com meaning the low frequency signal with a high-frequency radio
wave. the resultant wave is called modulated carrier wave.

 .  The high-frequency radio wave is modulation is called carrier wave. the low-frequency signal
is modulation is known as a modulation signal.

. Modulation is achieved by changing the amplitude are the frequency of the carrier wave is
accordance with the modulating signal. there are two types of modulations.

. Amplitude modulation a. M

  . Frequency modulation  f.m

. In in this type of modulation, the amplitude of the carrier wave is increased or decreased as
the amplitude of the superposing modulating signal increases and decreases.

 . Represent high-frequency carrier wave of consistent amplitude and frequency.

. Represents a low or radio frequency signal of the sine waveform.

. Shows the result obtained by modulating the carrier waves with the modulating wave.

the a.m. transmission frequencies range from 540 kilos Giga hard to 16 so gigahertz.

to transmit the signal for large range. M audio wave has a low-quality transmission of sound.

. In this type of modulation the frequency of the carrier wave increased or decreased as the modulatin
g signal amplitude increases or decreases but the carrier wave amplitude reminds system consists.
the frequency of the modulated carrier wave is highest when the signal amplitude is at its maximum
positive value.

. The frequency of the modulated carrier wave is lowest when the signal amplitude has maximum
aggregate value.