If you’re into FPV, you must have heard of clover leaf antennas. But, What’s a cloverleaf antenna? Why is it so hyped? It’s a closed-loop antenna with a wide band range. Its dipole antenna like radiation pattern is pretty efficient in reducing multipath interference.
A strong signal is a first & foremost need to fly an FPV. That’s where the circularly polarized cloverleaf antenna beats all other antennas out there.
Do you want to know how cloverleaf Antenna works? No worries, we have got your back!
What is Cloverleaf Antenna?
It’s a compact, wide-bandwidth, dual polarization cloverleaf-shaped antenna with a dipole antenna-like radiation pattern.
Yes, it indeed looks a bit childish. But it’s indeed the ideal antenna for FPV flying due to its low gain and perfect SWR.
Basics of Cloverleaf Antenna
Before the arrival of circular polarized antennas, every FPV enthusiast used to rely on linear antennas. These antennas could transmit signals only along a straight signal wire.
So, whenever an FPV had to pass by a building, the signal would be bounced back to the rider. This phenomenon is termed multipath interference.
As a result, the riders had to face a double-image view through video transmitters.
However, IBCrazy altered the future of FPV with its cloverleaf antenna in 2011.
Types of Cloverleaf Antenna
Before you fly your FPV, you have to hook the same type of antenna on your station. That’s why it’s a must to know about the types of clover leaf antenna, which include –
- Left Hand Polarized Antenna
- Right Hand Polarized Antenna
Structure of Cloverleaf Antenna
A Cloverleaf antenna might be equipped with 3-4 petals. In a 3-petal antenna, all the welding wire loops lie in the same horizontal plane. The angle of the petal is around 120°. The vertical plane makes a 45° angle with the horizontal plane.
Designing of Cloverleaf Antenna
The Cloverleaf antenna designs look pretty funky. But it indeed has some physics behind its design. Let’s check the antenna parameters out!
If it’s a cloverleaf antenna with an antenna feed of 5.8 GHz frequency, the approximate wavelength will be 5.17 cm (wavelength = speed of light÷ frequency).
A petal or wire loop measures around the wavelength. So, the dimension of the petal from the center will be 1.29 cm. (Dimension = wavelength/4).
The width of the antenna is around 2.58 cm. (Width = wavelength/2).
Radiation Pattern of Cloverleaf Antenna
Actual cloverleaf antennas have got huge popularity for their excellent radiation pattern.
Just like any other 3-dimensional object, imagine the cloverleaf antenna on an X, Y & Z axis.
The antenna gives off the highest radiation on the broadsides (X-Y Plane). But, it has almost no radiation along the axial axis (Z-axis).
But why does the 5.8GHz 4-leaf polarized antenna show this type of radiation pattern?
In a wired loop of a 4-arm cloverleaf antenna, the current always completes a full cycle.
Now imagine the same flow on the rest of the petals.
Here, the current flow from the adjacent pieces of wires cancels out all the peak currents. Moreover, the current flow through the outer rim is opposite to the antenna’s opposite side.
The vertical current also flows through only the broadsides (X-Y Plane).
That’s why there is a void on the z-axis, but the X-Y plane shows boosted radiation.
Properties of Cloverleaf Antenna
Cloverleaf antennas are super hyped as aerial antennae. But why?
- Firstly, it is a lightweight, low-profile antenna with a reliable transmission range.
- It transmits a signal at a frequency of 5.8 GHz.
- The Rx coax cable is slightly bendable, and the bent angle limit is specifically 28°.
Now let’s check some of its interesting antenna parameters!
Advantages of Cloverleaf Antenna
Cloverleaf Antenna is exclusively suitable for aero-modeling as it features –
- Dipole antenna-like radiation pattern for stable video transmission at any position and altitude.
- As it features a wider band range, the data transfer rate will be fast and accurate. In contrast, the multipath effect and power consumption will be significantly low.
- It is a low-gain antenna with wide-angle coverage.
- Its low SWR (1.0) is responsible for optimum operation throughout the radio channels.
Thus, it ensures the utmost antenna efficiency.
Disadvantages of Cloverleaf Antenna
- They are pretty big yet fragile.
- You just can’t trim it to the right frequency.
- Due to its erratic polarization rejection pattern, it’s not great for receiving signals.
- Building a cloverleaf antenna yourself is really a hassle.
Tips To Use A Cloverleaf Antenna
Is it your first time handling a cloverleaf antenna? Check our premium tips before you start!
- Install the antenna properly on your device before you turn the power on.
- You should place the antenna high up from the ground.
- Avoid any obstacle between two antennas.
- Never exceed the bent angle limit, as it might damage the antenna. It can also result in a performance drop.
Where should you place the clover leaf antenna?
You should place your clover leaf antenna in a high space. It will help to pick the weaker stations and avoid the TV signal blockers.
How far should the antenna be from the ground?
Your antenna should be at a high place, at least 10 to 20 feet far from the ground. Tall buildings or forests can significantly hamper signal transmission, even if it’s an omnidirectional antenna. So, it’s indeed ideal for pointing it towards the TV signal.
Is the 5.8 GHz antenna better than the 2.4 GHz One?
2.4 GHz antennas offer a wider transmission range. However, in terms of speed, 5.8 GHz antennas indeed have the upper hand.
How Far Does The 5.8 GHz antenna cover?
In ideal conditions, the highest coverage area will be 500 meters. But, network obstructors like forests & high-rise buildings can significantly reduce the coverage area.
Every FPV flyer out there loves a cloverleaf antenna for its crystal-clear video transmission. After all, it’s best to reduce multi-path interference. Moreover, the dipole radiation pattern has. significantly eased up the overall fpv experience. If you haven’t tried the cloverleaf antenna yet, go for it. It’s indeed a lifesaver!