With the help of block diagram describe how an amplitude modulated signal is detected by a radio receiver. Show graphically the detected wave and the msg signal retrieved.
The amplitude modulated signal is detected by the receiver as shown in the block diagram below.
The modulated signals are transmitted from the broadcasting stations. These signals are later received by the receivers. But the transmitted signal gets attenuated while passing through the channel. So, once the signal is received at the receiving antenna, it is passed through an amplifier. Then the carrier frequency is changed to lower frequency using an intermediate frequency (IF) stage and it is fed to the detector. The detected signal is again amplified. The process of recovering the modulating signal from the modulated carrier wave is called detection. The rectified output is received. The envelope of this output gives the message signal. This is passed through an envelope detector (RC circuit) and at the output the original message is recovered.
The graph of detected wave and the message signal retrieved is shown below.
