Horn Antenna is a kind of aperture antenna that is constructed uniquely with a flaring. It is one of the coolest kinds of systems in electromagnetism. Has understanding electromagnetic equipment like antennas has always been difficult for you?
No worries, today you’ll learn about it; especially about Horn Antennas in the simplest way that neatly accommodates the basic to advanced level knowledge in one place. Let’s not waste any more time and straightly jump into the details of Horn Antennas.
Basics Of Horn Antenna
Like I said earlier, Horn Antenna belongs to an individual category of antennas named Aperture Antenna. You know, Aperture Antenna consists of an aperture or an opening that helps the electromagnetic radio waves to go a certain way.
That’s why a waveguide is the best example for an Aperture Antenna. When a directional funnel shaped structure is added to the end of a waveguide, it is called a Horn Antenna. You can find an air horn shape extension (flaring) on the Horn Antenna; just like the name says. See, as simple as that!
Who Invented The First Horn Antenna?
Wilmer Barrow and G.C. Southworth 1938 invented today’s modern Horn Antenna. The first ever horn antenna was created by a Bengali-Indian radio researcher Jagadish Chandra Bose in 1897 while he was experimenting with microwaves at the very beginning
Why Is Horn Antenna Important?
Horn Antenna is important to make the maximum power transmission within the frequency range from a waveguide to the free space. Let’s see how. As a basis of electromagnetic radio wave factor you must know that the impedance between the waveguide and the free space needs to be matched in order to output a maximum power transmission.
A waveguide’s job is to restrict the transmission in a specific direction to guide the electromagnetic radio waves to the particular direction. Generally, a waveguide’s impedance is 50±10 ohms. On the other hand, the impedance of the free space around the waveguide is 377 ohms. You can clearly see it’s a big mismatch.
Working Of Horn Antenna
When the impedances don’t match the signals won’t be able to radiate from the waveguide to the free space, resulting in weak transmission.
To solve the issue a flaring is added and it is when the Horn Antenna enters. When the flaring is added at the end of the waveguide it assists to radiate the signals properly from the waveguide to the free space. And thus, the propagation is completed and turns into successful transmission.
Types Of Horn Antenna
Generally the frequency range of a Horn Antenna is 300MHz to 30GHz. It works both for UHF and SHF ranges.
Now, let’s learn about the different varieties of Horn Antennas. The four types of Horn Antennas are remarkable and used immensely. They are-
- Sectoral Horn Antenna
- Conical Horn Antenna
- Exponential Horn Antennas
- Pyramidal Horn Antenna
There are other variety of Horn Antennas-
- Corrugated Horn Antennas
- Dual-mode conical horn
- Diagonal horn
- Ridged horn
- Septum horn
- Aperture-limited horn
These Horn Antennas are also used and known for their individual advantages in many cases.
Structure Of Different Types Of Horn Antennas
Sectoral Horn Antenna was the primary structure of Horn Antenna. Later on other types were created as the need and broad categories of usage.
- Sectoral Horn Antenna
Sectoral Horn Antenna has only one sided directional flaring. It creates a fan shaped beam that is wide in the surface of the narrow sides and narrow in the surface of the wide sides.
This kind of Horn Antenna is widely used for broadband or broadcasting type coverage which is seen at base station transmission systems because of its wide frequency range. There Are two kinds of Sectoral Horn Antenna. They are-
1. Sectoral E Plane Horn Antenna
E Plane Sectoral Horn Antenna is a type of antenna where the direction is mouthed towards an electric vector.
2. Sectoral H Plane Horn Antenna
On H Plane Sectoral Horn Antenna is a type of antenna where the direction is mouthed towards the magnetic vector.
- Pyramidal Horn Antenna
Adding flaring on both sides a Pyramidal Horn Antenna is created. It has flaring on E and H both the walls and connected to make a four sided Pyramid shape. Pyramidal or Pyramid Horn Antenna generally works with rectangular waveguides.
- Conical Horn Antenna
Conical Horn Antenna forms a Cone/Circular shape with the flaring to the end. It is used with a circular waveguide.
- Exponential Horn Antennas
Exponential Horn Antennas are generally used in high frequency ranged applications, such as feed horns. Feed horns are used for communication satellite antennas and radios.
This horn antenna has curved sides, a constant impedance, and a very minimal level of internal reflection. They are also called Scalar Horn Antennas. Exponential Horn Antennas can have pyramidal or conical cross sections.
Advantages Of Horn Antennna
The structure of a Horn Antenna may confuse you but it surely has advantages.
- Horn antenna is made with a simple flaring which is shaped like a horn. That’s why the construction is very easy and simple.
- The shape of a Horn antenna also benefits the interface to the waveguide because of its simple design.
- There is no resonant element there in Horn Antennas. So, they can easily cover a large bandwidth.
Applications Of Horn Antenna
Horn Antennas are used in a variety of cases. Let’s discuss some of them.
- Microwave Engineering
Microwaves have to deal with shorter wavelengths and a directional way. They are not reflected and travel through a straight line in order of transmission.
These microwaves need a one directional antenna that can help the energy radiate correctly and make the best output. That’s why Horn Antenna is widely used in Microwave Engineering. It is also referred to as Microwave Horn Antenna.
- Feed For Parabolic Reflector
Parabolic Reflector Antennas contain reflector elements. It needs to be illuminated by some other method. Horn Antenna works great for illuminating the reflector element from the Parabolic Reflectors and works as the feed for Parabolic Reflector Antenna because of the wide bandwidth.
- Short Range Radar
One best example for it can be speed enforcement cameras. A Horn Antenna stops other reflections to interfere and precisely brings the actual response wanted.
Conclusion
As you’re still reading, I can assume this knowledge has helped you learn about Horn Antenna in detail. If you’re an enthusiast about antennas and electromagnetic radio signals, consider reading our other articles regarding antennas and radio signals.
Make sure you put your valuable comment down below to let us know how much this piece has helped you. Also write to us about what topic you want to know about further.
Others antenna
- Vivaldi Antenna
- Slotted Waveguide Antenna
- Telescope Antenna
- Slot Antenna
- Inverted-F Antenna
- Cavity-Backed Slot Antenna
References:
https://en.wikipedia.org/wiki/Horn_antenna
https://www.tutorialspoint.com/antenna_theory/antenna_theory_horn.htm
https://www.electronics-notes.com/articles/antennas-propagation/horn-antenna/basics-primer.php