COMMUNICATION SYSTEMS LAB
AM MODULATION USING MC 1496
Group members
M.Fuzail Awan(15020019020)
Ahmed Adnan Mirza(15020019014)
M. Sheriyar Munawar(15020019034)
Submitted To
Sir Abdullah Khalid
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COMMUNICATION SYSTEMS LAB
Modulation:
In electronics and telecommunications, modulation is the process of
varying one or more properties of a periodic waveform, called the carrier
signal, with a modulating signal that typically contains information to be
transmitted. Most radio systems in the 20th century used frequency
modulation (FM) or amplitude modulation (AM) to make the carrier carry
the radio broadcast.
Circuit diagram:
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COMMUNICATION SYSTEMS LAB
AM Modulation:
Amplitude modulation (AM) is a modulation technique used in electronic
communication, most commonly for transmitting information via
a radio carrier wave. In amplitude modulation, the amplitude (signal
strength) of the carrier wave is varied in proportion to that of the message
signal being transmitted. The message signal is, for example, a function of
the sound to be reproduced by a loudspeaker, or the light intensity of pixels
of a television screen. This technique contrasts with frequency modulation,
in which the frequency of the carrier signal is varied, and phase modulation,
in which its phase is varied.
Applications of AM modulator:
Amplitude modulation is used in a variety of applications. Even though it is
not as widely used as it was in previous years in its basic format it can
nevertheless still be found.
Broadcast transmissions: AM is still widely used for broadcasting
on the long, medium and short wave bands. It is simple to demodulate
and this means that radio receivers capable of demodulating amplitude
modulation are cheap and simple to manufacture. Nevertheless many
people are moving to high quality forms of transmission like frequency
modulation, FM or digital transmissions.
Air band radio: VHF transmissions for many airborne applications
still use AM. . It is used for ground to air radio communications as well
as two way radio links for ground staff as well.
Single sideband: Amplitude modulation in the form of single
sideband is still used for HF radio links. Using a lower bandwidth and
providing more effective use of the transmitted power this form of
modulation is still used for many point to point HF links.
Quadrature amplitude modulation: AM is widely used for the
transmission of data in everything from short range wireless links such
as Wi-Fi to cellular telecommunications and much more. Effectively it
is formed by having two carriers 90° out of phase.
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COMMUNICATION SYSTEMS LAB
Amplitude modulation advantages & disadvantages
Advantages
1. It is simple to implement
2. It can be demodulated using a circuit consisting of very few
components
3. AM receivers are very cheap as no specialized components are
needed.
Disadvantages
1. An amplitude modulation signal is not efficient in terms of its power
usage
2. It is not efficient in terms of its use of bandwidth, requiring a
bandwidth equal to twice that of the highest audio frequency
3. An amplitude modulation signal is prone to high levels of noise
because most noise is amplitude based and obviously AM detectors
are sensitive to it.
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