Amplitude ModulationPart - 1

The AM waveform

Modulating factor (m)

Sidebands

Forms of Amplitude Mod.

power saving = 66.7% at 100%

modulation

For M = 1,power saved is 1/6

of the total transmitted power

•83.3 % power saving•50 % B.W.•Very small Power Supply•Narrow BPF limits the noise pick up

Generation of DSB-SC Signals

AM using linear devices

ωc ei(t)Bandpass

filterat ωc

eo(t)

Ring modulator

ei(t)

Bandpass filterat ωc

eo(t)

cosωct

f(t)

cosωct

1/2eR 1/2eR

D 1

D2

D 3

D4

a

b

ei(t)eo(t)

Double Ring modulator

THANKS !