A corner reflector antenna is corner formed antenna that has a driven antenna and a half-wave dipole element connected with it. Also, two or more conductive metal sheets are intersecting 90 degrees to form this antenna.
Half-wavelength elements are used in this corner reflector design. Moreover, high-efficiency radiation is delivered in a symmetrical fashion by a balun-fed arrangement. The resulting performance is superior across all performance metrics, including bandwidth, gain, and match.
But do you know where you can use these corner reflectors? How it works and what are the applications?
Here we’ll discuss all these topics along with the benefits and disadvantages of the corner reflector. Let’s get started.
What is A Corner Reflector Antenna?
This is one of the directional antennas that used radio waves and frequencies. The most used frequencies of this antenna are VHF (very high frequency) and UHF (Ultra high frequency).
It’s made up of two flat rectangular reflecting screens linked at an angle, typically 90 degrees, in front of a dipole-driven element.
However, if you compare corner antennas with parabolic antennas you’ll find the core simplicity of design in corner antennas. These are basically modified versions of flat antennas.
This is because, by joining the metal sheets at a specific corner angle, it can create corner reflectors out of flat sheets or conducting sheets.
Sometimes this antenna consists of rod elements parallel and a wire screen which helps lower the weight and wind loads of the total antenna. Also, this antenna has 20 to 30 dB high-gain radiation, 10 to 15 dB moderate gain, and wide bandwidth applications.
Why Is Corner Reflector Antenna Important?
An antenna placed in a corner known as a corner reflector is a passive device that is used to redirect radio waves back toward the point of emission. Accordingly, the corner reflector is an effective tool for adjusting the precision of Radar systems. For the most part, a corner reflector is made up of two or more plates that cross each other at right angles.
When a broadband directional antenna with a size between one and one and a half wavelengths is required, corner reflector antennas excel. Since a parabolic dish of this size offers no performance benefit over a corner reflector, its low cost and easy assembly are major selling points.
Moreover, you can fill in shadows, direct light where you need it, and even bounce light off of and onto your subject with the help of reflectors.
How Does A Corner Antenna Work?
These antennas follow the laws of optics and the signal waves in the same direction from where it reflects. A corner reflector works on the basis that an electromagnetic wave is reflected once off each electrically conducting surface when it strikes the reflector.
As a result, a wave is reflected twice for a dihedral structure and three times for a trihedral structure.
Since it’s a passive device, it simply reflects waves back in the direction they came from. When arranging an antenna, a reflector is typically used to increase the antenna’s directivity.
The reflected energy is contained within the metal plate with the help of the corner-shaped reflectors. By redirecting the reflected energy back in the desired direction, the directivity is enhanced.
Resonance Of Corner Reflector
As already said that metal surfaces receive energy from the reflector so that it can oscillate itself after that it radiates the energy again. Here you’ll find a directional pattern due to the interference of different types of partial energy coming from the reflective array antenna.
However, here current induction will produce an echo signal since the energy of the secondary radiation is dispersed across multiple side holes.
But the current can produce a stronger field of radiation if you aligned the metal surface perpendicular to one another. One more thing you should keep in mind is that the reflecting surface should have a half wavelength in size in a polarizing direction for better radiation.
Furthermore, you should put two reflectors one will be longer and other one is shorter in size. The lowest resonant length of the corner reflector is an entire wavelength, therefore it must incorporate at least two reflecting surfaces.
Types Of Corner Reflector Antenna
There are two types of corner reflectors: Dihedral and Trihedral. Let’s know the details here.
- Dihedral Corner Antenna
When two conducting sheets are linked perpendicularly, a dihedral corner reflector is created.
- Trihedral Corner Antenna
Corner reflectors with three subareas are commonly used to eliminate backscatter caused by a deviation of the incident beams from the normal to the edge plane of the radar instrument. These reflectors are trihedral corners.
Advantages Of Corner Reflector
Let’s check some of the advantages of this antenna are as follows.
- Easy Construction
The structure and design of this reflector are very simple and easy to make. It means you won’t need any highly functional equipment to build this antenna.
- High Directivity
As it reflects the electromagnetic wave back in the direction it came from, it has a high degree of directivity.
Disadvantages of Corner Reflector Antenna
Here are the advantages of corner reflectors.
The reflector used in this antenna is quite expensive which makes the total process a bit costly.
In radar systems, these are primarily used to conceal the existence of defense vehicles from the eyes of the enemy. Due to its ability to reflect signals in the same direction they came from when is exactly 90° and the fact that these vehicles have less sharp edges, this suggests it is utilized for concealment.
How To Maintain Corner Reflector Antenna
At least once a month, you should take a moist rag to the antenna to get rid of dust and debris. The radio frequency connector’s external threads should be lightly lubricated. The best way to get consistent readings from your antenna is to have it calibrated at regular intervals.
Why are reflector antennas even necessary?
One or more reflecting surfaces and a feed system make up a reflector antenna. It has found widespread application in radars, satellite communications, deep-space telemetry, remote sensing, and radio astronomy as a result of its high radiation performances, adaptability, and production readiness.
What is a radar navigation corner reflector?
To send radio waves back in the direction they came from, the corner reflector is a passive device known as an emitter-follower pair. As a result, a corner reflector is an effective tool for adjusting the precision of radar systems. Perpendicular plates intersect each other to form the corner reflector.
Should a radar reflector be placed high or low?
The higher a reflector can be installed, the better, though ship captains should consider how the added weight can affect the ship’s stability.
Where exactly do you put the reflectors?
To maximize the effect of the light source, a reflector is typically positioned on the side of the subject that is opposite the light source. If the source of illumination is to the left, the reflector should be positioned to the right. When lighting a subject from in front, the reflector should be placed behind the subject.
Till now you got the idea of a corner reflector antenna, how it works, what are the benefits, and other important facts regarding this antenna.
The antenna’s gain is roughly in the middle of that of a plane reflective array and a parabolic antenna. This antenna excels in situations where a broadband directional antenna with a size of one to one and a half wavelengths is required.