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![ 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](https://image.slidesharecdn.com/presentation1-141210234020-conversion-gate02/75/Generation-of-SSB-and-DSB_SC-Modulation-5-2048.jpg)
![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](https://image.slidesharecdn.com/presentation1-141210234020-conversion-gate02/75/Generation-of-SSB-and-DSB_SC-Modulation-7-2048.jpg)
Uploaded byJoy Debnath
Generation of SSB and DSB_SC Modulation
The document discusses two methods of single sideband (SSB) modulation and balanced modulator modulation. It explains that SSB modulation eliminates one sideband from an amplitude modulated wave. It then describes the balanced modulator method, which uses two balanced modulators and a 90 degree phase shift to cancel out one sideband. The document also provides a brief overview of double sideband suppressed carrier (DSB-SC) modulation and notes that it uses two methods: multiplier modulation and balanced modulator.
In this document
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Presented by Joy Debnath and MD. Omar Faroque Tanzell, IDs 121-33-836 and 121-33-858.
SSB modulation eliminates components of one sideband; methods include Filter and Balanced modulator.
The balanced modulator method uses phase shifting to remove one sideband from an SSB signal.
Uses two balanced modulators to eliminate the carrier and produce SSB by algebraically combining outputs.
Modulated signal equation generates sum and difference frequencies for upper and lower sidebands.
DSB-SC modulation symmetrically spaces frequencies around carrier; composed with two methods: Multiplier and Balance.
Balance modulator suppresses the carrier by utilizing two amplitude modulations, producing the message signal.
A block diagram representation to visualize the modulation process.
Expresses thanks to the audience, concluding the presentation.
More Related Content
Generation of SSB and DSB_SC Modulation
- 1. Presented by JoyDebnath 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 usestwo 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 carriersignal 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 Abalance 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
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