The intelligence signal is in the AM envelope.
In AM modulation, the carrier is amplitude modulated by the signal. This signal appears as the envelope of the carrier. You can demodulate it by following the peaks on each cycle of the carrier. You can either follow the positive peaks or the negative peaks - it does not matter if the original modulation is symmetrical.
the low frequency signal which is nothing but the message signalNeither. The envelope will be that of the difference beat frequency. To get the envelope to follow the low frequency input signal you need to mix (multiply) the two signals, not add them.
You need modulation signal(carrier) which is a required signal in order to make envelope of time domained signal(target signal). The modulating signal is imposed on modulation signal.This creates envelope of waveform which is modulated(desired) signal. Now, the desired signals uper and lower sideband of signal strictly depends on modulation signal's bandwidth. Max. peak of that signal is uper sideband and min. peak is lower sideband for this modulated signal.
Pulse-Amplitude Modulation
The diode flips the entire signal to the positive region like a rectifier. Then the parallel rc combination is kept charged or discharged by the carrier frequency, 455kHz. Since the Signal sits on top of the carrier, the output is the original sent signal with some ripple distortion, this can be taken care of with a simple lowpass rc filter
while demodulating the modulated signal using coherent detection at the receiver end we need to generate the same carrier which is a very difficult ,it makes the receiver costlier and complex because the signal get distorted during the transmission process so generating the same carrier is quite impossible . if we are required to transmit the message to a large number of receivers than it will become very complex and costly. secondly when we modulate and send a pilot carrier it become possible to detect the signal by envelope detection method which requires very less circuitry and is very cheap. provided the sum of maximum amplitude of carrier and the message signal must be greater than zero so that the envelope gets a lift up.. the disadvantage of this scheme is that the higher transmission power is required...
Repetition rate of an AM envelope refers to the frequency of the modulating signal thus the shape of the envelope is identical to the shape of the modulating signal.
the low frequency signal which is nothing but the message signalNeither. The envelope will be that of the difference beat frequency. To get the envelope to follow the low frequency input signal you need to mix (multiply) the two signals, not add them.
The envelope of an AM waveform is a curve outlining the peaks of the modulated signal. It represents the variations in amplitude caused by the modulation process. The envelope is essential for demodulating the signal to recover the original message.
COMINT, ELINT, and FISINT
COMINT, ELINT, and FISINT
COMINT, ELINT, and FISINT
COMINT, ELINT, and FISINT
COMINT, ELINT, and FISINT
The envelope of a signal is the "apparent" signal seen by tracking successive peak values and pretending that they are connected. Normally, this question involves amplitude modulation of a radio frequency carrier by an audio frequency signal. The two frequencies involved are very much different - 20 kHz versus 1 mHz, for instance, and this "envelope" effect will be very noticable on an oscilloscope.
COMINT, ELINT, and FISINT
COMINT, ELINT, and FISINT
COMINT, ELINT, and FISINT