What is synchronous detection of AM signal?

What is synchronous detection of AM signal?

Explanation: Synchronous detection of AM signal requires local generation of the carrier signal at the receiver. The frequency of the locally generated carrier must be identical to that of transmitted carrier.

What is the basic component in a synchronous detector?

A synchronous detector consists of a reference value mixed (multiplied) with a specific modulation frequency to generate a modulated stimulus signal that is fed to the system under test (SUT) (Fig. 1). The SUT output is again mixed with the same modulation frequency.

What is synchronous AM mode?

Using synchronous AM (sometimes referred to as AM-Sync, Sync AM, S-AM or AM-S), the original carrier is mixed with a very stable carrier generated by a circuit known as a synchronous detector. As this signal is very stable, it is not subject to distortion because of fading.

What is the use of synchronous detector?

Synchronous detectors can extract small signals, buried in the noise floor, to measure properties such as very small resistance, light absorption or reflection against bright backgrounds, or strain in the presence of high noise levels. In many systems, the noise increases as the frequency approaches zero.

What is synchronous detection for SSB SC?

Here, the same carrier signal (which is used for generating SSBSC wave) is used to detect the message signal. Hence, this process of detection is called as coherent or synchronous detection.

What is synchronous or coherent detection?

We assume that this locally generated carrier is exactly coherent or synchronized in both frequency and phase with the original carrier wave c(t) used to generate the DSB-SC wave . This method of detection is therefore called as coherent detection or synchronous detection .

Why is it called synchronous detector?

In electronics, a synchronous detector is a device that recovers information from a modulated signal by mixing the signal with a replica of the un-modulated carrier.

Why is synchronous detection of AM signal considered a disadvantage?

Explanation: Disadvantage of synchronous detection of AM signal are that it needs an additional system for generation of carrier. It also needs additional system for synchronization of carrier. Moreover receiver is complex and costly.

What is the difference between coherent and noncoherent detection?

In coherent detection the local carrier generated at the receiver is phase locked with. the carrier at the transmitter. Hence it is also called synchronous detection. In non coherent detection the local carrier generated at the receiver not be phase.

What is the main difference between synchronous detection and envelope detection?

During good signal conditions and little or no interference there is really little audible difference between envelope and synchronous mode. Even when detecting C-QUAM stereo as QUAM your ear will tell a faint difference between the two but not as objectional as light to moderate interference would cause.