Lecture 2-Radio Theory

8/7/2019 Lecture 2-Radio Theory

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RANRANLecture 2:Lecture 2:

Radio Theory

By: Zuliana Ismail, 2010


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At the end of this lecture, the student shouldbe able to:

Describe about radio principles

Explain the applications of HF, VHF, UHF in aviations


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Radio is wireless transmission through space ofELECTROMAGNETIC WAVES in the approximate

frequency range from 10kHz to 300000MHz.


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Radio theory is essential knowledge for theunderstanding of the reasons why particularfrequencies are used for particular navigational

aids system (DME,VOR

& etc)


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Communication is a process of transmittingINFORMATIONfrom one location to another

MEDIUMis required for the delivery of the

information to be exchanged.

For example,

Transmission medium for television or

telephone is cable or fiber optics


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Radio transmission starts in US in 1920 with theinvention ofRADIO TRANSMITTINGEQUIPMENT that capable of transmitting voice

and music.


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TRANSMITTER : a device used to generate andtransmit radio signals [ELECTROMAGNETICWAVES].

RECEIVER : a device that receives incoming radiosignals andconverts themto sound or light.Example: receiver on radio or television convertingbroadcast signals into sound or images.


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In communication link, the TRANSMITTERisconnected through a cable to one ANTENNA.

ANTENNAis a device which provides means for

radiating or receiving radio waves.The signal is radiated to ANOTHERANTENNA,and then passes through another cable to theRECEIVER.

Broadcast systems such as TV or radio can usedone transmitter to serve many receivers via afree space link.


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Types of antennaTypes of antennaArr

ayA

ntenna

Reflector

antenna

WireAntennas


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Electromagnetic Wave = Electric wave + Magnetic Wave

Electromagnetic wave are used to transmit informationby wave motion.

Both waves oscillate at the same frequency

z

x

y

Electric Field

Magnetic Field


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The types of electromagnetic wave including:

RADIO WAVES(for TV, radio, aircraftcommunication)

Microwaves (radar, microwave oven)Infrared radiation (Body screening, remotes)

Visible Light (Bulb)

Ultraviolet (Medical Equipments)X-rays (Medical X-rays, Baggage Screening)

Gamma rays (Space Observations)


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Everyday technologies that depend on radio waves:

Standard broadcast radio and television

Wireless networks

Cell phones

GPS receiversAircraft Communications

ATC communications

Satellite communications

Police radios, Wireless clocks, Cordless phones ,Garage door openers


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PropertiesofRadio

Waves

In free space, they travel in

straight lines at the speedof

light c= 3v108 m/s.

Can be reflected,

refracted and

diffracted

Radio waves areradiated energy.

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Lecture 2-Radio Theory