Horn Antennas in Microwave Technology

Antenna and Microwave Laboratory
Babol Noshirvani University of Technology, Iran
In the name of God
Horn Antenna
 
Horn Antennas
 
Characteristics:
High gain
Low VSWR
Relatively Wide Bandwidth
Low weight
simplicity in construction
ease of excitation
One of the 
simplest
 and probably the most widely used 
microwave
 antenna is the horn.
its revival began in the late 1930s from the interest
in 
microwaves and waveguide transmission lines
during the period of World War II
The horn is nothing more than a hollow pipe of different cross sections,
which has been 
tapered
 (flared) to a larger opening.
The 
type
, 
direction
, and 
amount of taper 
(flare) can have a profound effect on the
overall performance of the element as a radiator
 
Horn Antennas
 
Horn is widely used as a 
feed element 
for large radio astronomy, satellite, tracking, and
communication dishes.
It is a common element of phased arrays and serves as a universal standard for calibration and gain
measurements of other high gain antennas.
They take many different forms as:
 
Horn Antennas
The horn is nothing more than a hollow pipe of different cross sections,
which has been 
tapered
 (flared) to a larger opening.
The 
type
, 
direction
, and 
amount of taper 
(flare) can have a profound effect on the
overall performance of the element as a radiator
 
 
Which is referred to as spherical phase term.
E-Plane Sectoral Horn Antennas
 
Aperture Fields:
Horn can be treated as an aperture antenna.
To find its radiation characteristics, equivalent principle techniques can be utilized.
Fields within horn can be expressed in terms of cylindrical TE and TM wave functions.
 
 
 
 
 
 
Fields can be found using:
 
 
 
 
 
 
Example:
an horn having 
a
=0
.
5
λ
, 
b
=0
.
25
λ
, 
b
1
=2
.
75
λ
 so that maximum phase deviation at aperture of horn is
56
.
72
o
.  Find Sectoral
 
angle
 
E-Plane Sectoral Horn Antennas
 
E-Plane Sectoral Horn Antennas
 
E-Plane 
Patterns:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
H-Plane 
Patterns:
 
 
 
 
 
 
 
 
 
 
 
 
 
H-Plane Sectoral Horn Antennas
 
 
Pyramidal Horns:
Most widely used horn is one which is flared 
in both
directions
 as:
Its radiation characteristics are a combination of 
E
 and
H 
plane Sectoral horns.
Aperture fields:
 
 
 
 
Equivalent currents:
 
 
 
 
 
 
Radiation fields:
Pyramidal Horn Antennas
 
 
Radiation fields (cont.):
 
 
It can be shown:
 
 
 
 
 
Far zone fields:
Pyramidal Horn
 
Pyramidal Horn
 
Radiation fields (cont.):
 
Pyramidal Horn
 
Radiation fields (cont.):
 
Pyramidal Horn
 
Pyramidal Horn
 
A commercial standard gain 
X
-band (8.2–12.4 GHz) horn:
It is a lightweight precision horn antenna for:
Standard for calibrating other antennas.
Feed for reflectors and lenses.
Pickup (probe) horn for sampling power.
Receiving and/or transmitting antenna.
 
Corrugated Horn
 
Corrugated Horn:
A large emphasis on horn antenna research in 1960s was:
Reduce spillover efficiency.
Cross-polarization losses.
Increase aperture efficiencies of large reflectors used in radio
astronomy and satellite.
In 1970s, high-efficiency and rotationally symmetric antennas were
needed in microwave radiometry.
Using conventional feeds, aperture efficiencies of 50–60% were
obtained.
However, efficiencies of order of 75–80% can be obtained with
improved feed systems utilizing corrugated horns.
Antenna pattern structure in back lobe region is strongly influenced
by diffractions from edges, especially from those that are
perpendicular
 
Corrugated Horn
 
17
Stack of sectoral feed horns for air
search radar antenna
50 ft. Holmdel horn antenna at Bell labs in Holmdel,
New Jersey, USA, with which Arno Penzias and
Robert Wilson discovered cosmic microwave
background radiation in 1964.
 
18
Feeding of Horn
 
Now, Let`s get familiar with a
brand new software:
Antenna Magus
 
Go to CST and simulate a example
And complete the work sheet
 
Worksheet
Please complete the work sheet to your example:
Frequency band :             ………
The figure of  antenna in CST :              ………
The of size antenna in 
λ
 and in cm/mm  :      ………
S
11 
:          ………              (set Z0=75 ohm)
Zin (Re and Im) in CST  :   ………
Surface Current (phase=0 deg) :    ………
linear 3D Power Pattern in CST :  ………
2D Power Pattern for theory & CST :    ………
HPBW for theory & CST :   ………
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Horn antennas are integral in microwave technology, offering high gain, low VSWR, and wide bandwidth. Widely used for radio astronomy, satellite communication, and more, horns play a crucial role in various applications. Learn about the design, characteristics, and radiation properties of horn antennas through insightful descriptions and visuals from the Antenna and Microwave Laboratory at Babol Noshirvani University of Technology in Iran.


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  1. In the name of God Antenna and Microwave Laboratory Babol Noshirvani University of Technology, Iran Horn Antenna Antenna and Microwave Laboratory Babol Noshirvani University of Technology zakeri@nit.ac.ir

  2. Horn Antennas One of the simplest and probably the most widely used microwave antenna is the horn. its revival began in the late 1930s from the interest in microwaves and waveguide transmission lines during the period of World War II Characteristics: High gain Low VSWR Relatively Wide Bandwidth Low weight simplicity in construction ease of excitation The horn is nothing more than a hollow pipe of different cross sections, which has been tapered (flared) to a larger opening. The type, direction, and amount of taper (flare) can have a profound effect on the overall performance of the element as a radiator Antenna and Microwave Laboratory Babol Noshirvani University of Technology zakeri@nit.ac.ir

  3. Horn Antennas Horn is widely used as a feed element for large radio astronomy, satellite, tracking, and communication dishes. It is a common element of phased arrays and serves as a universal standard for calibration and gain measurements of other high gain antennas. They take many different forms as: Antenna and Microwave Laboratory Babol Noshirvani University of Technology zakeri@nit.ac.ir

  4. Horn Antennas The horn is nothing more than a hollow pipe of different cross sections, which has been tapered (flared) to a larger opening. The type, direction, and amount of taper (flare) can have a profound effect on the overall performance of the element as a radiator Antenna and Microwave Laboratory Babol Noshirvani University of Technology zakeri@nit.ac.ir

  5. E-Plane Sectoral Horn Antennas Aperture Fields: Horn can be treated as an aperture antenna. To find its radiation characteristics, equivalent principle techniques can be utilized. Fields within horn can be expressed in terms of cylindrical TE and TM wave functions. Fields can be found using: Difference in path of travel designated as: Which is referred to as spherical phase term. Example: an horn having a=0.5 , b=0.25 , b1=2.75 so that maximum phase deviation at aperture of horn is 56.72o. Find Sectoralangle Using Binomial Expansion: Antenna and Microwave Laboratory Babol Noshirvani University of Technology zakeri@nit.ac.ir

  6. E-Plane Sectoral Horn Antennas Where: Antenna and Microwave Laboratory Babol Noshirvani University of Technology zakeri@nit.ac.ir

  7. E-Plane Sectoral Horn Antennas E-Plane Patterns: Antenna and Microwave Laboratory Babol Noshirvani University of Technology zakeri@nit.ac.ir

  8. H-Plane Sectoral Horn Antennas H-Plane Patterns: Antenna and Microwave Laboratory Babol Noshirvani University of Technology zakeri@nit.ac.ir

  9. Pyramidal Horn Antennas Pyramidal Horns: Most widely used horn is one which is flared in both directions as: Its radiation characteristics are a combination of E and H plane Sectoral horns. Aperture fields: Equivalent currents: Radiation fields: Antenna and Microwave Laboratory Babol Noshirvani University of Technology zakeri@nit.ac.ir

  10. Pyramidal Horn Radiation fields (cont.): It can be shown: Far zone fields: Antenna and Microwave Laboratory Babol Noshirvani University of Technology zakeri@nit.ac.ir

  11. Pyramidal Horn Radiation fields (cont.): Antenna and Microwave Laboratory Babol Noshirvani University of Technology zakeri@nit.ac.ir

  12. Pyramidal Horn Radiation fields (cont.): Antenna and Microwave Laboratory Babol Noshirvani University of Technology zakeri@nit.ac.ir

  13. Pyramidal Horn Antenna and Microwave Laboratory Babol Noshirvani University of Technology zakeri@nit.ac.ir

  14. Pyramidal Horn A commercial standard gain X-band (8.2 12.4 GHz) horn: It is a lightweight precision horn antenna for: Standard for calibrating other antennas. Feed for reflectors and lenses. Pickup (probe) horn for sampling power. Receiving and/or transmitting antenna. Antenna and Microwave Laboratory Babol Noshirvani University of Technology zakeri@nit.ac.ir

  15. Corrugated Horn Corrugated Horn: A large emphasis on horn antenna research in 1960s was: Reduce spillover efficiency. Cross-polarization losses. Increase aperture efficiencies of large reflectors used in radio astronomy and satellite. In 1970s, high-efficiency and rotationally symmetric antennas were needed in microwave radiometry. Using conventional feeds, aperture efficiencies of 50 60% were obtained. However, efficiencies of order of 75 80% can be obtained with improved feed systems utilizing corrugated horns. Antenna pattern structure in back lobe region is strongly influenced by diffractions from edges, especially from those that are perpendicular Antenna and Microwave Laboratory Babol Noshirvani University of Technology zakeri@nit.ac.ir

  16. Corrugated Horn Antenna and Microwave Laboratory Babol Noshirvani University of Technology zakeri@nit.ac.ir

  17. Stack of sectoral feed horns for air search radar antenna 50 ft. Holmdel horn antenna at Bell labs in Holmdel, New Jersey, USA, with which Arno Penzias and Robert Wilson discovered cosmic microwave background radiation in 1964. zakeri@nit.ac.ir 17 Antenna and Microwave Laboratory Babol Noshirvani University of Technology

  18. Feeding of Horn zakeri@nit.ac.ir 18 Antenna and Microwave Laboratory Babol Noshirvani University of Technology

  19. Now, Let`s get familiar with a brand new software: Antenna Magus Antenna and Microwave Laboratory Babol Noshirvani University of Technology zakeri@nit.ac.ir

  20. Go to CST and simulate a example And complete the work sheet Antenna and Microwave Laboratory Babol Noshirvani University of Technology zakeri@nit.ac.ir

  21. Worksheet Please complete the work sheet to your example: Frequency band : The figure of antenna in CST : The of size antenna in and in cm/mm : S11 : (set Z0=75 ohm) Zin (Re and Im) in CST : Surface Current (phase=0 deg) : linear 3D Power Pattern in CST : 2D Power Pattern for theory & CST : HPBW for theory & CST : Antenna and Microwave Laboratory Babol Noshirvani University of Technology zakeri@nit.ac.ir

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