FPV antenna is the deciding factor that determines the range and signal strength of your FPV system. This guide will explain the basics of 5.8Ghz antennas used on mini quad VTX and VRX, and hopefully it will help you choose the best FPV antenna.
To learn more about FPV, make sure to check out our complete guide to FPV system.
The Best FPV Antennas for Mini Quad
Onmi Antennas (Best Value)
As mentioned previously, the pagoda is a simple yet effective design. The affordable material and easy assembly allows price to drop significantly. You can find the pagoda at around $5 to $10 each, making it one of the best value antenna out there.
There are a few different manufacturers for the Pagoda antenna, such as Lumenier, MenaceRC, Emax, Farview and Realacc.
Foxeer makes some of the best value antennas in the market. The Lollipop 2 might not be the best performance, but they do have good enough quality for those who are on a budget to replace the stock Dipole’s. These antennas are very durable thanks to the thick plastic housing. The new version has improved considerably in terms of performance from the original antennas.
The Aomway 4-lobe’s are tried and tested antennas. They have been around for years and remain to be a good choice in terms of performance. However there is concern over robustness due to the exposed design. There is now a new version that comes with plastic caps that protects the lobes.
Onmi Antennas (Top Of The Line)
Unlike the classic cloverleaf and skew planar wheel, the TBS Triumph Pro is very compact and protected in a sealed plastic case, makes it very durable. It claims to have one of the most impressive axial ratios (0.99), which means it has really good multipath interference rejection.
The Lumenier AXII 2 by GetFPV is also a very small and strong antenna. The unique design provides uniform signal coverage, giving you equally good signal when flying behind yourself. These are available in many variations: MMCX, UFL, SMA, different stem lengths, enough to cover most if not all of your needs.
|Lumenier AXII 2||Banggood
Directional Antennas (Cheap Worth Having)
The Menace Pico-Patch is a very compact and affordable directional patch antenna with wide signal coverage, delivers decent performance, great for FPV drones. Check out my review of the Pico-Patch
Directional Antennas (Top of the Line)
This is the antenna to go for if you want a high gain directional antenna for long range, it provides a 10dB gain and yet giving you 120 beam-width.
Another compact directional antenna that doesn’t look bulky on your slimline FPV goggles. Compared to the X-Air, the AXII Patch has lower gain, but wider signal reception.
What is FPV Antenna
An antenna is a piece of wire, or pieces of wire that convert electrical power into electromagnetic waves. The receiving antenna converts the electromagnetic waves back into electrical power.
In FPV, antennas (or antennae) enable wireless communication between the video transmitter (VTX) and receiver (VRX). Antennas in your FPV system are critical elements that determine the range and signal quality.
FPV Antenna Anatomy
Every antenna consists of the same basic parts regardless design or external appearance.
- Active Element – conductive material that transfers and receives radio wave signal in the air
- Coaxial Cable – a special shielded cable that carries signal from the connector to the antenna element without emitting radio signals. They are used to extend the length of the antenna, and often are made of rigid material so it can be bent to any desired angle. Coaxial cables are not necessary if the connector is directly connected to the element
- Connector – used to connect the antenna to a video transmitter or receiver.
FPV antenna elements are made of fragile copper wires or other conductive material, therefore it’s common to see antennas come in plastic protective housing. These housing or cases do not weaken the signal and provides support for the antenna in crashes.
Antenna Polarization – Linear or Circular
Antenna polarization is a classification of FPV antennas. There are two types:
- linearly polarized antennas (LP)
- circularly polarized antennas (CP)
This post explains the differences between Linear and Circular Polarized antennas in a bit more detail.
Circular polarized antennas are the standard for FPV drones for a couple of reasons:
- Linear polarized antennas are very sensitive to multipathing interference while CP antenna is not as badly affected
- LP antennas have to be aligned well to work well, however antenna alignment is very hard to maintain on a quadcopter as it’s rotating around all axes constantly
Multi-Pathing is interference/noise in your video feed, it happens when video signal bounces off objects such as walls and ground, the reflected signals become out of phase and could interfere with the main signal. Multipath interference often appears as random static in the video feed.
For general FPV drone flying, it’s recommended to use circular polarized antennas. However, some pilots might prefer specially made LP antennas, because they can be made smaller, lighter, and more durable, despite of the worse RF performance.
Using LP and CP Antenna Together
You can mix linearly polarized antenna and circularly polarized antennas in your FPV system, at the cost of some signal loss.
It’s not unheard of some racers use a dipole antenna on the mini quad (which is linear) to save weight, and use a circular antenna on the video receiver.
This way you get the light weight benefit of the LP antenna, and signal strength due to antenna orientation is more forgiving, however you will suffer from a signal loss of about 3dB (30%). RHCP or LHCP, doesn’t matter in this case. But it’s still better than the worse situation when only using linear polarized antennas on both ends, where the maximum reduction in signal is 97% (30dB). It’s a compromise.
Differences between LHCP and RHCP
There are two types of circular polarized antennas, “left-hand” (LHCP) and “right-hand” (RHCP).
You are supposed to use the same type of antenna on both receiver and transmitter. If you mix LHCP and RHCP you will suffer from considerable signal loss. What happens when I mix LHCP with RHCP antennas?
When one pilot is using LHCP antennas and the other using RHCP, there will be less interference between them.
LHCP antenna rejects signal from RHCP antenna and vice versa, and interference is reduced between the two VTX’s.
For the same reason, using circularly polarized antennas helps minimize multipath interference. Every time a signal bounces off the wall or ground, it changes the direction of polarization. For example, a bounced LHCP signal becomes RHCP which will be rejected by the receiving LHCP antenna.
For pilots flying in a group, it’s best to have both LHCP and RHCP antennas for flexibility. If you are just flying alone most of the time, then this doesn’t really matter.
Directional and Omni-directional Antennas
Another classification of FPV antennas is directionality:
As you could guess from the names, omni-directional antennas radiate their radio waves equally in all directions, while directional antennas focus their radio waves to one direction.
One classic analogy is bulb vs torch, where the bulb is Omnidirectional and the torch is directional. If both light sources are operating at the same power, torch can reach further but in the expense of narrower beam width.
Directional antennas can be linear polarized or circularly polarized, same as omni-directional antennas.
Omnidirectional antennas are great for every-day flying, and it provides good signal coverage all around the pilot. Try to avoid using only directional antennas so you don’t have to constantly turning yourself to face directly towards your copter.
However directional antennas are often used on diversity receivers, where it can be paired with an omni-directional, or multiple directional antennas to cover all the necessary angles.
Diversity receiver can receive two signals from two antennas instead of just one, and it can then choose to display the stronger signal.
For example, if you have a diversity setup with a CP antenna and a helical antenna, the receiver will switch to the helical antenna when flying in front and to the CP antenna when flying behind.
Antenna Performance Measurements
There are many antenna performance measurements regarding FPV antenna design, such as:
- Radiation Pattern
- Axial ratio
- Tuned Frequency and bandwidth – what frequency is the antenna tuned to, and the range of working frequency
I mainly look at the first four factors when choosing my antennas. Anyway, as long as you are buying your equipment from a name brand you shouldn’t worry too much about it. In my opinion we are not flying a rocket for NASA and there is no need to cause headache for yourself in this case :)
But if you want to find out more about these concepts, both antenna-theory.com and wikipedia are great resources for learning about antennas. In the following sections I will try to briefly explain what these terms mean.
Gain is an indicator of directional antenna’s range and angle of coverage. Higher gain generally means further range but narrower beam width. Antenna gain can alter radiation pattern as we will see in a moment.
Tutorial: How antenna gain affects range?
Radiation pattern (radiation chart) shows the shape of the radiation emitted by the antenna. These charts can tell where the weak spots are and how likely it is to lose signal.
Here are some examples to help you visualize the the signal coverage patterns.
A 0dB gain antenna is truly omni-directional that has a nearly perfect spherical radiation pattern.
However omni-directional antennas in real life usually has signal loss on the top and bottom, and the radiation pattern would look more like a doughnut in 3D. In a two-dimensional view, it forms a figure-of-eight pattern in the vertical plane, and a circle in horizontal plane.
Here is the radiation pattern for an 8dB gain patch antenna. Notice the narrow beam width in both vertical and horizontal planes.
Low DB gain might seem a bit less appealing in terms of range, but it can offer more reliable performance thanks to the more spherical radiation pattern, you can get reasonably strong signals even by pointing the antenna straight at the receiver.
In reality there is no perfect circular polarized antenna. For example, a RHCP antenna might output 90% of RHCP signal with 10% LHCP signal. So there might still be interference even if you were doing everything perfectly. And Axial Ratio is used to measure this antenna property.
In practical FPV flying terms, this is the measurement of how susceptible the antenna is to multipath interference. Antennas with better capabilities of rejecting multipathing makes it easier to fly in areas with lots of concrete and metal.
Antennas with the axial ratio closer to 1, the better.
Frequency and Bandwidth
Antennas are tuned for a specific frequency, for example, the length of a dipole antenna determines the frequency it’s tuned to. The antenna would have the best performance when transmitting and receiving at this frequency.
If you transmit or receive at a slightly higher or lower frequency, the antenna would still have acceptable performance, and this “acceptable range” is the bandwidth. Outside of the bandwidth, signal strength is greatly reduced or even rejected.
You should understand what frequency your antenna is tuned for, and what the bandwidth is, in order to select the most effective channel/frequency to use. Otherwise you will be more likely to get interference and lose picture.
It can even cause overheat and damage to the video transmitter, because sending power into an unmatched antenna can reflect power back where it can build up as heat.
Anyway, for FPV most antennas designed for 5.8GHz should be fine for all the channels in A, B, E, F and R bands, unless it’s stated otherwise in the product specifications.
Stands for “Voltage Standing Wave Ratio”. It’s a measure of how efficient an antenna is – how much energy you put into the antenna and how much is bounced back.
When we are designing an antenna, we aim for a VSWR value as close to 1 as possible. At 1 VSWR, it means we can transfer 100% of the energy into the antenna, and out to the real world.
It’s considered reasonable to have a VSWR between 1 and 2, anything above 2 is poorly performing.
Note that VSWR changes with frequency. When talking about the tuning of an antenna, basically that’s the frequency with the lowest VSWR.
OwlRC makes a cheap VSWR (or SWR) meter for hobbyist use.
Types of Antennas
We have covered most of the basics in FPV antenna, and now I can finally introduce you some common types of antennas used for FPV.
|Linear Polarized||Monopole, Dipole||Patch|
|Circular Polarized||Cloverleaf, Skew-Planar Wheel, Pagoda||Helical, Patch, Crosshair|
Monopole antenna is the simplest form of antenna, which is basically just a piece of un-shielded wire. It’s very common in radio receivers because they are cheap and easy to repair. However they are not as effective as Dipole antennas. The length of the exposed wire is crucial as it determines the resonant frequency (frequency that it can pick up).
Tutorial: how to make Monopole antenna.
Nearly all video transmitters and receivers come with a dipole antenna. They are light weight, and can be made very durable against crashes.
Dipole antennas has a simple design. It’s basically just a monopole antenna with a ground sleeve at under the active element. The ground sleeve can supposedly boost the performance considerably.
Cloverleaf and Skew-Planar Wheel Antennas
The cloverleaf and skew-planar wheel have been the most common antennas for mini quad FPV. Cloverleaf has 3 lobes while skew-planar wheel has four lobes.
These antennas are omni-directional like dipole. But they are circularly polarized and provide better reception and yet also less susceptible to multi-pathing, so you can fly around walls and trees with better video quality.
They are however relatively fragile therefore often come in different cases and protection. They are sometimes called “mushroom antenna” because of the shape of the housing.
Pagoda is a relatively new antenna design in the FPV scene since 2016. It’s an omnidirectional circular polarized antenna. The unique design and use of material (PCB) makes it very durable. It’s relatively easy to make and so very popular among DIY’ers as well.
See our discussion on Pagoda antennas for more detail.
Helical antennas are spring-shaped, directional circular polarized antennas. The number of turns of coil determines the gain of the antenna. For more detail check out our article on Helical antenna and Patch antenna.
Patch antennas are also directional, and can be found in linear and circular polarization.
These antennas are less laborious to manufacture on a reliable way, as they are essentially just copper traces printed on circuit boards. However the dielectric constant of the circuit board means they are inherently less efficient compared to other types of antennas such as the helical.
They generally have less directionality than Helical, and smaller foot-print.
Considerations in Choosing Antenna for FPV
For beginners, it’s best to start with omni-directional circularly polarized antennas, for example the cloverleaf or pagoda.
Antenna performance relies heavily on decent material and precision, good antennas would therefore cost more. However some top notch antennas can cost 2 to 3 times more than the lower end ones, while they might only bring 5% or 10% range improvement.
Axial ratio is also an important factor to consider, which isn’t normally mentioned by manufacturer. But you might be able to find out their performance from reviews online.
After all, it all depends on what you can afford and your research on products.
Once you’ve invested in a diversity receiver setup, you can then look into getting some directional antennas to improve signal quality and range.
What Antennas For VTX and VRX
When buying FPV antennas in pair, normally they are interchangeable and can be used on either TX or RX. Otherwise, they should be clearly labelled “TX” and “RX” on the outside.
Antennas on VTX and VRX don’t have to be the same. Directional antennas are often used on VRX to get more range. While on the VTX you should always use omni-directional antennas, due to the fact that quadcopters can be in different orientation during flight.
Antenna Connector Types
For antenna connectors, we normally have SMA and RP-SMA. They are different in design and not compatible with each other, so make sure you buy the right one. Check this article to see the differences between SMA and RP-SMA. If you new to the hobby, try to stick with just SMA for your gear to avoid confusing yourself in the future. There is no difference in performance.
“U.FL” connectors are popular in VTX designed for racing due to the light weight and compact size for mini quad. But these are extremely fragile and have very limited mating cycles.
MMCX is a new type of connector that is being used in VTX and antennas. It’s a perfect balance between SMA and U.FL connectors in terms of weight and size. It’s much stronger than U.FL and have a lot more mating cycle. This is the my personal favorite at the moment.
A racing drone will inevitably experience many crashes during its life time. Since the antenna is installed on the outside of the frame, it will take no less abuse than the propellers and the frame. Therefore choose your antenna base on your likelihood of crashing. If you crash a lot, durability and robustness should be your priority in choosing FPV antenna.
One thing people usually overlook is the size and weight of the antenna. It’s becoming more important as mini quads are getting lighter and lighter. Every gram you save can improve the performance of your quad.
Antenna Adapters and Extension Cables
You can get adapters to convert between different connectors (RP-SMA, SMA, MMCX, U.FL etc). These adapters can even come with 45 degrees or 90 degree angle if you want to point the antenna at certain angle.
Adaptor and extension cable can cause signal loss, how much depends on the quality and design. But usually the loss is very small, e.g. a few percent. If you can achieve what you want, for example moving your antenna away from sources of interference, or pointing the antenna at a more optimal angle, it might be worth it.
DIY FPV Antenna
5.8GHz antennas for FPV are not hard to DIY, but to get it perform well requires high level of precision. I do recommend buying them because they are not that expensive, but if you are feeling adventurous feel free to give it a go :)
- My attempt at making cloverleaf antennas: https://oscarliang.com/make-diy-cloverleaf-antenna/
- Pagoda assembly video: https://www.youtube.com/watch?v=49rRR8iEiKc
- DIY Helical by IBCrazy: https://www.rcgroups.com/….Circularly-Polarized-Helical-antenna…
So that covers some of basics and considerations in choosing your 5.8GHz FPV antenna, and some antenna recommendations for FPV flying. I hope this guide has helped you to choose the best FPV antenna for your mini quad!
- May 2017 – Article Created
- Sep 2018 – Updated “Antenna Recommendations” and Added info about “Antenna Frequency”
- March 2019 – added info about VSWR, adapters and extension cables
- July 2020 – updated products