communications engg 1

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INTRODUCTION TO ELECTRONIC

COMMUNICATIONS


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ELECTRONICS

Computers largest field in terms of sales of

equipment and services and number of employees

Computer Industry concerned with the

development and servicing of computer hardware

and software used by businesses, industry and

government for the processing, storage andretrieval of data.


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ELECTRONICS

Communications

second largest in size

Communications Industry

concerned with electronic equipment

used for transfer ofinformation between

two or more points.


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ELECTRONICS

Control

smallest field

Control Field

concerned with electric power as wellas various kinds of electronic

components and circuits used to operatelights, heating elements, electric motorsand other devices.


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ELECTRONICS

Communications

- components

- circuits- techniques

- applications


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COMMUNICATION

Communication

basic process of exchanginginformation

transferring of information from oneplace to another

Human

convey their thoughts, ideas andfeelings to one another

- spoken words / non-verbal / letters


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COMMUNICATION

Barriers of Human Communications

1. Language

2. Distance


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ELECTRONIC COMMUNICATIONS

Electronic Communication

transmission, reception and

processing ofinformation

between twoor more locations using electronic

circuits.


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History

Late 19th century electricity was discovered

1837 1844 FirstE

lectronic CommunicationsSystem


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1866 First Successful use of a Transatlantic

Telegraph Cable


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1876 Telephone


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1887 Hertz discovers Radio Waves


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1894 95 Wireless Telegraphy


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1901 First Transatlantic Radio Transmission


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1903 Fleming Valve was invented


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1906 08 Triode Vacuum Tube / First Radio

Telephone Broadcast


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1920 First Commercial Radio (AM)


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1923 Television was invented


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1931 Radio Astronomy


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1933 FM


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1936 First FM Commercial Broadcasting


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1940-45 RADAR was perfected


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1948 Transistor was invented


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1954 Colored Television


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1959 - Integrated Circuits


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1962 First Commercial Satellite


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Modern Electronic Communications System

1. metallic cable systems

2. microwave and satellite radio systems

3. optical fiber systems


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Elements of a Communication System

TransmitterCommunication

Channel or

Medium

Receiver

Noise

Message for

Human

Application

Human

Message

Input


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Transmitter

collection of electronic components

and circuits designed to convert the

information into a signal suitable for

transmission over a given

communications medium


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Communication Channel

medium by which the electric signal is

sent from one place to another

Radio

general term applied to any form of

wireless communications


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Receiver

electronic components and circuits that

accept the transmitted message from the

channel and convert it back into a form

understandable by humans


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Noise

random, undesirable electric energy

that enters the communication system

via the communication medium and

interferes with the transmitted message.


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Types ofElectronic Communications

A. One Way or Two Way

B. Types of Intelligence Signals TransmittedC. Baseband or Modulated Signals


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One Way or Two Way Transmission

1. Simplex one way communicationcommunications

2. Half Duplex one party transmits at a time

3. Full Duplex can transmit and receivesimultaneously

4. Full Full Duplex possible to transmit andreceive simultaneously, but not necessarilybetween the same two locations.


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Types of Intelligence Signals Transmitted

1. Analog Signal a continuously varying

voltage or current

2. Digital Signal digital codes / data

Digital Communications

1. Digital Transmission2. Digital Radio


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Baseband or Modulated Signals

Baseband Transmission putting the original

voice, video, or digital signals directly into the

medium.

Modulation process of having a baseband

voice, video, or digital signal modify another

higher frequency signal.

communications engg 1

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