Download - Horn Antenna presentation of Antenna Theory

T.CSuleyman Demirel University

College of Engineering Electronic And Communications Eng. Department

Horn Antenna Representation of Antenna Theory

By MSc. Students

Khaled Saeed Al BadriMohammed Mahdi

A COURSE OFFERED BY: Dr. Evren Ekmekçi

What is Horn Antenna:

A horn antenna horn is an antenna that consists of a flaring metal shaped like a Horn.

By Khalid Saeed And Mohammed Mahdi SDU

Horn Antenna- The first horn antennas constructed by Indian radio researcher in 1897. [3]

- In World War 2 the development stimulated horn research to design feed horns for radar antennas.[1] - In 1962 horn antenna has become widely used as a feed horn for microwave antennas such as satellite dishes and radio telescopes.[3]

50 ft. Holmdel horn antennaThe 64 meter radio telescope


How Horn Antenna Work

- Horn Antenna converts the electric power into radio waves and vise versa. It is usually used with a radio

transmitter or radio receiver . -It provides a gradual transition structure to match the impedance of a tube to the impedance of free space, enabling the waves from the tube to radiate efficiently into

space .


Range Of Frequencies:

Horns operates at UHF and Microwave frequencies, above 300 MHz..


Waveguide:

Waveguides are rectangular or circular shaped tubes. They are used for energy and information transfer in electromagnetic systems. Electromagnetic waves travel along waveguides by means of multiple reflections from the metallic walls. Generally metallic waveguides have one conductor and

operate at frequencies above 1 GHz .


Waveguide:

Metallic waveguides is important components of many technologies with practical applications such as radar antenna feeds, circuitry, waveguide slot

antenna arrays, horn antennas, microwave filters and other various other circuit component .


Horn Antenna Types:

1 .Rectangular feed-horns : -Sectoral E-plane horns -Sectoral H-plane horns

-Pyramidal feed-horns

2 .Conical feed-horns .


Sectoral E-plane horns

In E-plane sectoral horn the opening is flared in the direction of the E-field.


The Radiation Pattern Sectoral E-plane horns

The E-plane pattern is much narrower than the H-plane because of the flaring and larger dimensions of the horn in that direction


H-Plane Sectoral Horn:

In H-plane sectoral horn the opening is flared in the direction of the H-field, while keeping the other constant.


Radiation Pattern of H-Plane Sectoral Horn:

The H-plane pattern is much narrower than the E-plane because of the flaring and larger dimensions of the horn in that direction


Pyramidal Horn :

The most widely used horn is the one which is flared in both directions and its radiation characteristics are essentially a combination of the E-and H-plane sectoral horns .


Radiation Pattern of Pyramidal Horn :

the pattern of a pyramidal horn is very narrow in both principal planes and in fact, in all planes .


Conical Horn.

Conical feed-horns are fed with a metallic circular waveguide in mono-mode operation


Gain

Horns have very little loss, so the directivity of a horn is roughly equal to its gain.

The gain G of a pyramidal horn antenna is:

For conical horns, the gain is:

A is the area of the aperture.d is the aperture diameter of a conical hornλ is the wavelength,eA is a dimensionless parameter between 0 and 1 called the aperture efficiency.


Why we use Horn Antennas?

-They can operate over wide ranges of frequencies.

-Very wide bandwidth, for example allowing it to operate

from 1GHz to 20GHz, 20:1.

-High Directivity.

-High gain.

-Support for wide applications .


Applications of Horn Antenna:

-They are used as feeders (called feed horn) for larger antenna structures such as parabolic antennas, as directive antennas for such devices as radar guns, automatic doors openers, microwave radiometer.

-A common element of phase array . -Satellite and microwave communications.

-Used in the calibration, other high gain antenna.-Used for making electromagnetic interference

measurement .


References:

1. Antenna theory analysis and desgin by Balanis.

2. Design and Performance Analysis of 10 GHz Horn Antenna By

ARPN Journal of Science and Technology.

3. http://en.wikipedia.org/wiki/Horn_antenna.

4. Antenna theory by Stutzman.


Download - Horn Antenna presentation of Antenna Theory

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