Advantages and disadvantages of amplitude modulation

AM stands for Amplitude modulation, the amplitude of the RF carrier is varied in accordance with the amplitude of modulating signal input. The transmission of a wave signal by modulating the amplitude of the signal is an amplitude modulation. Amplitude modulation is widely used in radio communication over long distances in transmission. Here this article gives the advantages and disadvantages of analog modulation to better understand this topic.

Advantages of Amplitude modulation:

  • AM signal is reflected back to earth from the ionosphere layer. Due to this fact, AM signals can reach far places that are thousands of miles from the source. Hence amplitude modulation the radio has coverage wider as compared to the Frequency modulation radio.
  • It is a low cost.
  • It requires a lower carrier frequency.
  • It is easily available.
  • Require a simple and cheaper transmitter and receiver.
  • An easier method for transmitting and receiving an audio signal
  • It is simple with proven reliability.

Disadvantages of Amplitude modulation:

  • The most natural as well as man-made radio noise are too much of in this type of modulation. The AM receivers will not have any means to reject this kind of noise is to be generated.
  • This modulation will require more than twice the amplitude-frequency to modulate the signal with a carrier.
  • The quality of the audio signal is poor.
  • Weak AM signal has a low magnitude compare to strong signals. This requires AM receiver to have circuitry to compensate for the signal level difference.
  • Low efficiency as the information is contained only in the sideband.
  • AM requires a bandwidth which is double to the audio frequency.
  • The efficiency of such a system is very low as it consumes a lot of power for modulations and this causes a considerable operational cost.
  •  This limits the application of amplitude modulation to radios, VHF, and system used for one to one communication only.
  • This deteriorates the quality of the original signal at the receiving end and causes problems in the quality of the signal.