Slide on Amplitude Modulation

1. AMPLITUDE
MODULATION

2. CONTENTS
INTRODUCTION
AMPLITUDE MODULATION
COEFFICIENT OF MODULATION
AM VOLTAGE DISTRIBUTION
AM POWER DISTRIBUTION
BENEFITS OF AM

3. INTRODUCTION
Amplitude Modulation is the simplest and
earliest form of transmitters
AM applications include broadcasting in
medium- and high-frequency applications.

4. Amplitude Modulation
 Amplitude Modulation is a process of
changing the amplitude of a relatively high
frequency carrier signal in accordance with
the amplitude of the modulating signal.

5.  The modulating signal:
 The Carrier Signal:
The AM signal
  )cos()]cos([ tctmmVcVtamV 
 tVm
  tVtV ccc cos

7.  The Envelope:
 The AM Signal

8. COEFFICIENT OF AMPLITUDE
 The ratio between the amplitudes between
the amplitudes of the modulating signal and
carrier, expressed by the equation:
c
m
E
E
m =

9. AM VOLTAGE DISTRIBUTION

10. AM POWER DISTRIBUTION
Power in an AM transmitter is
calculated according to the formula
at the right







2
1
2
m
PP ct
USBLSBct PPPP 

11. Benefits of Amplitude Modulation
Modulation can shift the spectral
content of a message signal into a
band which is better suited to the
channel
Hence, to transmit and receive, say,
voice, by radio we need to shift the
voice signal to a much higher
frequency band.

12. THANKS
EVERYONE