1. Presented by
Joy Debnath ID:121-33-836
MD. Omar Faroque Tanzell ID:121-33-858

2. Single Sideband (SSB) Modulation
 SSB modulation is a type modulation that elements all
components of one sideband from an amplitude
modulated wave.
 SSB =(message*carrier)+(message with 90⁰ of phase
shift*carrier with 90⁰of phase shift)
 There are two methods used for SSB Modulation.
1.Filter Method
2.Balanced modulator Method

3. Balanced modulator Method
 The Balanced modulator
method of SSB
generation uses a phase
shift technique that
causes one of the side
bands to be connected
out. A block diagram of a
phasing type SSB
generator is shown in fig.

4.  It uses two balanced modulators instead of one. The
balanced modulators effectively eliminate the carrier.
The carrier oscillator is applied directly to the upper
balanced modulator along with the audio modulating
signal. Then both the carrier and modulating signal
are shifted in phase by 90o and applied to the second,
lower, balanced modulator. The two balanced
modulator output are then added together
algebraically. The phase shifting action causes one side
band to be canceled out when the two balanced
modulator outputs are combined

5.  The carrier signal is VcSin2πfct the modulating signal
is VmSin2πfmt. Balanced modulator produces the
product of these two signals.
(VmSin2πfmt)(VcSin2πfct)
Applying a trigonometric identity.
(VmSin2πfmt)(VcSin2πfct) = 1/2[Cos(2πfc - 2πfm)t -
Cos(2πfc + 2πfm)t]
these are the sum and difference frequencies or the
upper and lower side bands.
It is important to remember that a cosine wave is
simply a sine wave shifted by 90o A cosine wave has
exactly the same shape as a sine wave, but it occurs 90o

6. Double-sideband suppressed-carrier
Modulation
 Double-sideband suppressed-carrier modulation
(DSB-SC) is a modulation in which frequencies
produced by amplitude modulation (AM) are
symmetrically spaced above and below the carrier
frequency and the carrier level is reduced to the lowest
practical level, ideally being completely suppressed.
 DSBSC= the message * the carrier
 There are two methods used for DSB-SC Modulation
1. Multiplier modulation
2. Balance modulator

7. Balance Modulator
A balance modulator consists of two standards
amplitude modulations arranged in a balanced
configuration, so as to suppers the
carrier wave, as shown in block.
S₁(t)=Ac[1+Kₐm(t)] cos(2πfᴄt)
S₂(t)=Ac[1-Kₐm(t)] cos(2πfᴄt)
S(t)= S₁(t)- S₂(t)=2KₐAc cos(2πfᴄt) m(t), which is equal
to the produced message signal

8. Block diagram

9. Thanks to all