Lecture 2-Radio Theory

RAN Lecture 2: Radio Theory  By: Zuliana Ismail, 2010

At the end of this lecture, the student should be able to: Describe about radio principles Explain the applications of HF, HF, VHF, VHF, UHF in i n aviations aviatio ns

Radio

is wireless transmission through space of  ELECTROMAGNETIC WAVES in the approximate ap proximate frequency range from 10kHz to 300000MHz.

Radio

theory is essential e ssential knowledge for the understanding of the reasons why particular frequencies are used for particular navigational aids system (DME,VOR & etc)

Communication

is a process of transmitting INFORMATION from one location to another MEDIUM is required for the delivery of the information to be exchanged.

For example, Transmission medium for television or telephone is cable or fiber optics

Radio

transmission starts starts in US in 1920 with the RADIO TRANSMITTING invention of  transmitting voice EQUIPMENT that capable of transmitting and music.

TRANSMITTER : a device used to generate and transmit radio signals [ELECTROMAGNETIC WAVES]. RECEIVER :

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

In communication link, the TRANSMITTER is connected through a cable to one ANTENNA. ANTENNA

is a device which provides means for radiating or receiving radio waves. The signal is radiated radiated to ANOTHER ANTENNA, and then passes through another cable to the RECEIVER. Broadcast systems such as TV or radio can used one transmitter to serve many receivers via a free space link.

Types of antenna ay ay Antenna Arr 

Reflector  antenna

Wir  e Antennas

Electromagnetic Electromagnetic Wave = Electric wave + Magnetic Wave Wave

Electromagnetic wave are used to transmit information by wave motion. Both waves oscillate at the same frequency Electric Field

z

y Magnetic Field x

The types of electromagnetic wave wave including: RADIO WAVES (for TV, radio, aircraft communication)

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 Observa Obser vations) tions)

Everyday technologies that depend on radio waves : Standard broadcast radio and television Wireless networks Cell phones

GPS receivers Aircraft Communications ATC

communications

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

Radio waves are

radiated energy ene rgy..

Properties of  Radio

Waves

Can be reflected,

refracted and diffracted

travel in In free space, they travel of  straight straight lines at the speed  8 light c  =  3 v10 m/s.