# Why is there a phase reversal in DSB-SC?

## Why is there a phase reversal in DSB-SC?

The ‘phase-reversal’ is the generated DSB-SC waveform can be seen during every zero-crossing of the message because it is accompanied by the zero- crossing of the carrier. waveform, obtained when the message and carrier are from a single phase-synchronized dual function generator.

### Can envelope detector be used for DSB-SC?

Unfortunately, the envelope detector cannot be used to demodulate a DSBSC signal. To understand why, recall that the envelope detector outputs a signal that is a copy of its input’s envelope.

#### What are the types of DSB-SC modulators?

The following two modulators generate DSBSC wave.

• Balanced modulator.
• Ring modulator.

What are DSB modulators?

Double-sideband suppressed-carrier (DSB-SC) modulation is an amplitude modulation that consists only of the two symmetrical sidebands and no carrier band. I came across this scheme in an ultrasound application, where power utilization can be maximized when all power is available on the sidebands.

What is meant by phase reversal?

A phase reversal fault is a situation where two phases in a three phase system have been swapped. This typically occurs during equipment installation, upgrades or general maintenance. 3-phase motors and other rotating equipment rely on the order of the phases to be correct.

## What is phase reversal modulation?

[′fāz ri‚vər·səl ‚mäj·ə′lā·shən] (communications) Form of pulse modulation in which reversal of signal phase serves to distinguish between the two binary states used in data transmission.

### How do you demodulate a DSB-SC?

Demodulation. For DSBSC, Coherent Demodulation is done by multiplying the DSB-SC signal with the carrier signal (with the same phase as in the modulation process) just like the modulation process. This resultant signal is then passed through a low pass filter to produce a scaled version of the original message signal.

#### How is DSB-SC signal detected?

Coherent Detector Here, the same carrier signal (which is used for generating DSBSC signal) is used to detect the message signal. Hence, this process of detection is called as coherent or synchronous detection. Following is the block diagram of the coherent detector.

How DSB-SC is modulated?

Double-sideband suppressed-carrier transmission (DSB-SC) is transmission 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.

How DSBSC is modulated?

## Which type of modulator is suitable for DSB AM signal?

The type of modulation that will be studied in this chapter is called double-sideband suppressed-carrier amplitude modulation (DSBSC-AM). A close approximation to an ideal coherent demodulator called a Costas loop will be implemented.

### Why is the phase reversal?

Incorrect phase sequence within a three phase system is called phase reversal. Phase reversal usually occurs as a result of mistakes made during equipment installation, maintenance, or modifications to the facility power system.

#### What are the application of SSB?

Application of SSB SSB transmission is used in the applications where the power saving and low bandwidth requirements are important . The application areas are land and air mobile communication, telemetry, military communications, navigation and amateur radio .

What is switching modulator?

Switching modulator is similar to the square law modulator. The only difference is that in the square law modulator, the diode is operated in a non-linear mode, whereas, in the switching modulator, the diode has to operate as an ideal switch.

What is the bandwidth of DSB-SC signal?

2fm
We know that the DSBSC modulated wave contains two sidebands and its bandwidth is 2fm.

## How are DSB-SC signals generated?

DSB-SC is generated by a mixer. This consists of a message signal multiplied by a carrier signal. The mathematical representation of this process is shown below, where the product-to-sum trigonometric identity is used.