What is message demodulation, Electrical Engineering

Assignment Help:

Q. What is Message Demodulation?

The major advantage of the conventional (standard) DSB AMsignal transmission is the ease with which the signal can be demodulated. Themessage signal is received by passing the rectified signal through a low-pass filterwhose bandwidthmatches that of themessage signal. The combination of the rectifier and the low-pass filter is known as an envelope detector, which is almost universally used. A standard AMenvelope detector consisting of a diode and an RC circuit (which is basically a simple low-pass filter) and its response are shown in Figure.

During the positive half-cycle of the input signal, the diode is conducting and the capacitor charges up to the peak value of the input signal. When the input falls below the voltage on the capacitor, the diode becomes reverse-biased and the input becomes disconnected from the output. During this period, the capacitor discharges slowly through the load resistor R. On the next cycle of the carrier, the diode conducts again when the input signal exceeds the voltage across the capacitor. The capacitor charges up again to the peak value of the input signal, and the process is continued. The time constant RC must be selected to follow the variations in the envelope of thecarrier-modulated signal. Generally, it is so chosen that

1441_What is Message Demodulation.png

470_What is Message Demodulation1.png

The simplicity of the demodulator has made conventional DSB AM a practical choice for AM radio broadcasting. A relatively inexpensive demodulator is very important in view of the several billions of radio receivers. With only a few broadcast transmitters and numerous receivers, the power inefficiency of conventional AMis justified. Thus, it is cost-effective to construct powerful transmitters and sacrifice power efficiency in order to have simpler signal demodulation at the receivers.


Related Discussions:- What is message demodulation

Diac - power semiconductor devices , Diac Diac is a device which  has d...

Diac Diac is a device which  has di electrode  and as its name suggests it works  on AC. The cross  sectional view of a diac is shown if the four layers are PNPN and PNPN .

Explain soft magnetic materials, Explain Soft magnetic materials. So...

Explain Soft magnetic materials. Soft magnetic materials -They contain small enclosed area of hysteresis loop, high permeability low eddy current losses and high saturation

Octal number systems, Octal Number Systems Now the  question may  arise...

Octal Number Systems Now the  question may  arise in one mind  that why  to learn  octal  number  system when  neither  human  nor the  digital  systems  uses. It  hence it is

Lhld load hl pair direct instruction, LHLD  Load  HL Pair Direct  Instru...

LHLD  Load  HL Pair Direct  Instruction This  instruction is used to copy the  content  of memory  location specified  by opened  in register L  and copy the content of next  m

Analog-to-digital converters, Analog-to-Digital (A/D) Converters An A/D...

Analog-to-Digital (A/D) Converters An A/D converter converts analog input signals into digital output data in many areas such as process control, aircraft control, and telemetr

Necessary conditions to maintain sustained oscillation, Q. What are the nec...

Q. What are the necessary conditions to maintain sustained oscillation? The use of positive feedback that results in a feedback amplifier having closed-loop gain |Af| greater t

Applications platform - gis applications, Applications Platform: GIS a...

Applications Platform: GIS applications should be capable to act as a base system over which the other business process application can be integrated which is the objective of

Determine the input current and input voltage, Q. A 100-kVA, 2300:230-V, 60...

Q. A 100-kVA, 2300:230-V, 60-Hz, single-phase transformer has the following parameters: R 1 = 0.30 , R 2 = 0.003 , RC 1 = 4.5k, X 1 = 0.65 , X 2 = 0.0065 , and Xm 1 = 1.

The time constant of the circuit, A 20µF capacitor is connected in series w...

A 20µF capacitor is connected in series with a 50 kΩ resistor and the circuit is connected to a 20 V, d.c. supply. Verify: a)  The initial value of the current flowing, b)  T

What is the difference between a tem mode and a te mode, Q. (a) What is the...

Q. (a) What is the difference between a TEM mode and a TE mode? (b) Explain the terms "cutoff wavelength" and "dominant mode" as applied to waveguides. Find the cutoff wavelengt

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd