Analog Communication

Jan 12 • Notes • 3349 Views • 6 Comments on Analog Communication

What is the difference between digital communication and analog communication?

Analog means continuous transmission of data whereas digital means discrete transmission of data. In analog communications we are transmitting finite amount of data in infinite amount of information. so,there is a possibility of occurrence of noise. where as in digital we are transmitting finite amount of data in finite amount of information. so , out of these two, digital is most efficient.
Analog means continuous transmission of data whereas digital means discrete transmission of data. In analog communications we are transmitting finite amount of data in infinite amount of information. so,there is a possibility of occurrence of noise. where as in digital we are transmitting finite amount of data in finite amount of information. so , out of these two, digital is most efficient.

What are the objectives met by analog modulation?

Length of antenna is shortened, signal loss is reduced, ease of radiation, adjustment of bandwidth, shifting signal frequency of the assigned value.

What are advantages of analog communication?

It is simpler No coding and Decoding problem.
It require only easy demodulation and modulation circuitry
Process is inexpensive and low transmission and reception cost
occupy lower bandwidth as compared to digital communication.

What is analog-to-digital conversion of signals?

A discrete-time signal is defined by specifying its value only at discrete times, called sampling instants. When the sampled values are quantised and encoded, a digital signal is obtained. A digital signal is obtained from the analog signal by using an analog-to-digital converter. This entire process is referred to as the conversion of signals from analog to digital form.

What is Frequency modulation (FM)?

Ans:Frequency modulation is the process of varying the frequency of a carrier wave in proportion to the instantaneous amplitude of the modulating signal without any variation in the amplitude of the carrier wave. In Frequency modulation is the process of varying the frequency of a carrier wave in proportion to the instantaneous amplitude of the modulating signal without any variation in the amplitude of the carrier wave. In analog applications, the difference between the instantaneous and the base frequency of the carrier is not directly proportional to the instantaneous value of the input-signal amplitude but it is proportional to frequency.

What is amplitude modulation?

Amplitude modulation (AM) is a technique used in electronic communication, most commonly for transmitting information via a radio carrier wave. AM works by varying the strength of the transmitted signal in relation to the information being sent. For example, changes in signal strength may be used to specify the sounds to be reproduced by a loudspeaker, or the light intensity of television pixels

In radio communication, a continuous wave radio-frequency signal (a sinusoidal carrier wave) has its amplitude modulated by an audio waveform before transmission. The audio waveform modifies the amplitude of the carrier wave and determines the envelope of the waveform.

 

Why negative feedback is applied in AM transmitters?

Ans. Generally, negative feedback is provided in AM transmitters in relation to the modulating signal. The radiated signal is picked up from the antenna, demodulated and combined with the modulated signal and used as negative feedback at the appropriate point. The negative feedback can be used with low level modulators, as well as with high level modulators.

Advantages of using negative feedback with transmitters are same as with amplifiers. The negative feedback reduces amplitude as well as frequency distortion thus increases faithfulness of the transmitter. The negative feedback also reduces the undesirable hum and noise in the transmitter.

Classify AM modulators.

The AM modulators may be classified as

(1) Linear Modulators—These make use of linear part of the V-I curve of the transistors (or diodes). The examples of these are collector modulators and base modulators.

linear modulators are of two types-(i) Collector Modulator

(ii) Base Modulator.

(2) Non linear or Square Law Modulators—These make use of non linear part of the VI characteristic of the transistors (or diodes).

non-linear modulators are of two types-(a) Product modulator(b) Ring modulator.

What is the basic requirement of an AM transmitter?

To generate AM waves we supply current pulses to a tuned (tank) circuit. Each pulse is made proportional in amplitude to the size of the modulating sine wave. This will be followed by the next sine wave proportional to the next applied pulse and so on. At least 10 times pulses per cycle should be fed to the circuit; and if the current pulses are made proportional to the modulating voltage, we get a good AM wave.

– This is called “Flywheel Effect” of the tuned circuits and holds good for a tuned circuit whose Q factor is of moderate value.

How FM transmitters differ from AM Transmitters?

Ans. The FM transmitters have a very large bandwidth as compared to AM transmitter. In FM transmission ground wave and sky wave propagation is not possible, and signals in VHF and UHF bands are proppagated by line of site propagation, which restricts the range upto 50 km.

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6 Responses to Analog Communication

  1. Ritika says:

    Analog communication was a very important part of communication & still finds usage at places.

  2. sakshi chaudhary says:

    Satisfactory and useful explanation of analog communication..!!!!
    Analog communication includes transfer of continuous data from transmitter to the receiver but sometime it is affected by the noise and other factors so in order to reduce this problem now a days digital communication has over come analog communication…

  3. Ankita Prajapati says:

    This post contains information about “Analog Communication”..its really helpful!!!!

  4. Saurabh Singh says:

    this post contains good collection of question and it is very helpful to those students who are related to communication field..check this for more information..

  5. Siddhant Tripathi says:

    Important concepts and informative stuff over analog communication.

  6. lubna khan says:

    If you will add some picture of modulated and unmodulated waveforms ,THIS WILL BE MORE UNDERSTANDABLE.

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