Question

Write the functions of the following in communication systems:
A) Transmitter
B) Modulator

Answer 1

Hint: A communication system is an integrated whole of different units that are transmission systems, communication channels and receivers. Transmitter is used in relaying signals whereas a modulator is used whenever required to avoid dispersion of signals.

Complete answer:
First of all let us examine a communication system. So, communication is the process of transferring information to the receiver from the sender. And a communication system is a network of interconnected systems used in the process of communication. It primarily has three units. They are transmitter unit, communication channel and receiver.
Both transmitter and modulator are important units in a communication system. The message cannot be transmitted through the communication channels in its raw form. Therefore the transmitter is used.
As the name suggests, a transmitter is a device that is used to transmit the information to the receiver from the sender. This is possible by converting the information which is to be relayed, into a form which can be transmitted through the communication channels. Again based on the requirements, a modulator may be used.
The function of a modulator is to modulate the signal, which is the information, in order to transmit it over longer distances. When message signals are transmitted over longer distances, there is a chance for the signal to get dispersed. To avoid this, the low frequency message signal is superimposed on a high frequency carrier. This is the process of modulation. Examples of communication systems that we see around us are the internet, mobile networks, television etc.

Note: In a communication system, generally a transmitter is placed at one place and the receiver is located at some other place, and is connected by a medium. For example, the radio broadcasting or mobile service.