An amplitude modulated (AM) signal carries information by varying the amplitude of a carrier wave in accordance with the modulating signal (e.g., an audio signal). When this modulated signal is received by an AM receiver, the following effects occur:
Demodulation: The primary task of the receiver is to extract the original modulating signal from the received AM signal. This process is called demodulation. Various demodulation techniques are used, such as envelope detection or synchronous detection, to recover the modulating signal.
Signal Reconstruction: Once the modulating signal is extracted, it is used to reconstruct the original information. In the case of audio transmission, the demodulated signal is typically amplified and sent to a speaker to produce sound.
Noise and Interference: The AM signal is susceptible to noise and interference during transmission. The receiver may encounter various sources of noise, including atmospheric noise, electromagnetic interference, or noise introduced by electronic components. These can affect the quality of the received signal and introduce unwanted artifacts or distortions.
Signal Fidelity: The fidelity of the received signal depends on factors such as the signal-to-noise ratio, the quality of the demodulation technique, and the transmission conditions. If the signal-to-noise ratio is low or if interference is significant, the quality of the received signal may degrade, resulting in reduced fidelity.
Overall, the effect of an AM signal on a receiver is to extract and reconstruct the modulating signal, with the quality of the received signal dependent on the demodulation technique used and the presence of noise or interference.