ANALOG-TO-ANALOG
CONVERSION
n Analog-to-analog conversion, or analog
modulation, is the representation of analog
information by an analog signal.
n One may ask why we need to modulate an
analog signal; it is already analog.
n Modulation is needed if the medium is bandpass
in nature or if only a bandpass channel is
available to us.
n Analog-to-analog conversion can be
accomplished in three ways: AM FM and PM.