Emg Yagi-uda Antenna

8/2/2019 Emg Yagi-uda Antenna

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LECTURER:

EN. MUHAMAD HAFIZ BIN SHAFIE


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GROUP MEMBER:

MOHAMAD AZWAN B. HUSSAIN DE100042

CT SHUHANA BINTI BAHAYAHKHI CE100150SAIDATUL RABIAH BINTI MD FADZIL CE090047

HASMAH BT IBERAHIM CE090134


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The Yagi-Uda array was invented in 1926 byShintaro Uda of Tohoku Imperial University,

Japan, with a lesser role played by his

colleague Hidetsugu Yagi.

The work was originally done by Shintaro Uda,but published in Japanese.

The work was presented for the first time in

English by Yagi (who was either Uda's professor

or colleague) who went to America and gavethe first English talks on the antenna, which led

to its widespread use.


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Hence, even though the antenna is often

called a Yagi antenna, Uda probablyinvented it.

Its one of the most famous and used

directional parasitic antennas.


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A picture of Professor Yagi with a Yagi-Udaantenna


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The Yagi-Uda antenna is directional antenna

designed to maximize reception over long distances.

Generating a much higher signal-to-noise ratio than other

antenna designs, the Yagi-Uda antenna has become the de

factor standard in antenna applications in almost all

stationary applications utilizing frequencies above 10 MHz.


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A Yagi-Uda antenna is familiar as the commonest

kind of terrestrial TV antenna to be found on the

rooftops of houses. It is usually used at frequencies

between about 30MHz and 3GHz, or a wavelength range

of 10 metres to 10 cm.


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Yagi antenna usually used at frequencies betweenabout 30MHz and 3GHz


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This middle element is generically called the"driven element". This is because this is the only

element that is connected directly to the radio,

it actually drives the whole antenna.

The other two outer elements are generically

called parasitic elements. One is called the

Reflector and the other one is called the

Director element.

These elements get their name from the job

they do. The reflector reflects RF energy, the

director directs RF energy.


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Driven element with twin lead cable connection

Twin lead


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Driven element with coaxial cable connection


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The entire range of radiation covering the frequencies from 0 to

approximately 10^23 hertz. In order of decreasing frequency the radiation

goes, cosmic rays, gamma rays, x-rays, UV radiation, visible light, infrared

radiation, microwaves, and radio waves.

A simple antenna with two equal length rods extending outward from

each other in a straight line. When current passes through the dipole,

radiation is emitted.

The element of a Yagi-Uda array that is connected to the signal

generator. The remaining elements are known as directors or reflectors.


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The element of a Yagi-Uda array that reflects the focused signal back

toward the driven element.

The distance it takes for a waveform to propagate one cycle.

The elements of a Yagi-Uda array that direct and focus the signal

towards the driven element and reflector.


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The number of cycles a waveform completes in one second.

A term referring to electrical charge passing through a medium.

The measure of how much the signal is amplified by the antenna.


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Refers to the current that is produced in a medium when that medium is

exposed to a magnetic field (and the medium is not directly coupled with the

magnetic field source).


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In the field of antenna design the term radiation

pattern (or antenna pattern or far-field

pattern) refers to the directional (angular)

dependence of the strength of the radio

waves from the antenna or other source.


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There is no magic circuit located inside the elements, theyare simply straight rods!

The reflector element is typically 5 % longer than the

driven element and the director is typically 5 % shorted than

the driven element.


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Schematic of the operating principle of the original YagiUda

antenna for radio frequencies.


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Signal comes in-phase


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Yagi-Uda antenna pattern (2D)


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Signal comes out-phase


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Signal comes out-phase


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We can even add more directors elements to increase the gain.

Adding more reflector elements has NO more effect on the gain of

the antenna.


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Yagi-Uda antenna pattern (2D)
http://principle%20of%20a%20yagi%20antenna%20%281%29.flv/


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http://users.marktwain.net/aschmitz/anten

nas/calcantenna.html

http://mapleleafcom.com/calculator_3element_yagi.shtml


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www.authorstream.com/Presentation/saharan49-605897-antenna-ppt/

www.hamuniverse.com/yagibasics.html

en.wikipedia.org/wiki/Yagi-Uda_antenna

signalengineering.com/ultimate/yagi.html

www.authorstream.com/Presentation/sachin

sachin-180517-basic-antenna-theory-

concepts-entertainment-ppt-powerpoint/

mapleleafcom.com/calculator_3element_yag

i.shtml

www.changpuak.ch/electronics/yagi_uda_an

t h

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Emg Yagi-uda Antenna