In this article, McGill Microwave Systems will provide a guide to help you choose the best antenna for your hotspot location.
McGill Microwave Systems are a team of highly experienced RF engineers with a combined experience of over 60 years.
Our passion is to be the recognised global market leaders in the design and manufacture of the highest performance RF/Microwave Interconnect solution and world class Antenna designs for all of the market sectors that our company is active in globally today.
Having built up an enviable reputation and track record in providing world-class RF/Microwave solutions every day for the most challenging of applications – be it for Spaceflight applications, Manned and Unmanned Military aircraft, I.E.D Roadside Bomb defeating systems, Electronic Warfare systems.
We are also very active in commercial telecommunications applications in the Oil & Gas, Rail, Marine, Medical, Automotive, 5G and last, but not least, the Helium/IOT marketplace!
McGill Microwave Systems are perhaps best known globally in the Helium/IoT community for our best-in-the-world McGill Antennas & Ultra Low Loss, High Performance LMR™ Coaxial Cable assemblies. This is complimented by our range of unique and innovative solutions we have invented and developed to solve Helium installation issues – including our lowest RF loss window pass through interconnect solution on the market today, lightweight and extendable masts and now passive and active RF solutions to boost the performances of Helium Hotspots.
It’s become a daily occurrence here at McGill Microwave Systems for customers to ask for our recommendation on what would be the best Antenna choice to achieve optimum performance for a given Helium hotspot location. It should be understood that even with access to powerful RF Propagation and Topography modelling tools, there are many other factors which can come into play which affect RF signal transmission which cannot be modelled or accounted for such that, historically, any antenna recommendation would only get you “in the ballpark”.
Final antenna optimisation could only be achieved by experimenting with different antennas.
However, there is now a new and brilliant tool available from McGill Microwave Systems which has been specifically designed for Helium installations, which for the first time can now provide instant answers to this question – we will discuss this later in the article!
There are many misconceptions in the IOT/Helium community where BIGGER is BETTER, or viewed as an upgrade. This may be true in some cases, but various locations require different antenna gains (both low and high) to achieve optimum performance.
There are also locations that may be much more suited to a different type of Antenna design compared to the much more common Omni Directional Antenna designs used by the Helium community.
This alternative antenna design is known as Directional /Panel antennas -also known as “Sector Antennas”
Antenna placement is sometimes overlooked, however it’s no trade secret that the antenna placement is the most important consideration to ensure adequate witnesses and good rewards. “Height is King” is what the McGill team often say when working with clients on optimising setups. This is because clear line of sight ensures that the RF signal remains unaffected by any potential obstructions.
Imagine your antenna is a torch, emitting light from it. If you were to put an object such as a building, tree or hill in front of it, the light will likely not pass through the object. This is similar when trying to radiate the RF signal through such objects.
Antenna Placement & Directional Antennas
Let’s analyse the below Directional Antenna and it’s placement
Good Location – Better Antenna Choice – McGill Microwave 13dBi Directional Panel Antenna
The Antenna placement above is located on McGill Microwave Systems Headquarter building and is being used as a test bed for the new McGill Microwave 13dBi directional antenna.
Even although at the time of writing (March 2022) the overall Helium earnings for everyone are lower, this antenna still clears around 30HNT per month (Equivalent to 1 HNT Per day) and is mounted in on a 2 Metre pole on the side of our building with a 6 metre LMR 600 cable assembly directly connected to a standard hotspot. No RF Filters, no Amplifiers are used here.
It currently therefore ranks well within the top 1,500 hotspots globally – so within the top 0.01% of the 600,000 or so hotspots in the world.
Why is this setup doing so well?
Well, although not a classical high altitude location that is generally ideal for such a Directional Antennas (the building is only 140m above sea level), these results have been obtained using our latest Antenna innovation – our McGill Tuned & Optimised 13dBi Directional Panel antenna. This Panel antenna is Directional has been specifically selected for this location placement -as opposed to a traditional Omni Directional Antenna design.
We decided that this Directional antenna may prove to be the ideal choice here because this is a location where you have minimum hotspots behind (North of) the location. It was therefore decided that we should use the available RF Antenna Power more efficiently and use our Tuned & Optimised 13dBi Directional Antenna to focus the power more towards the city of Edinburgh, located some 20-40 KM away where there is potential to pick up significantly more witnesses.
The McGill 13dBi Directional antenna still boasts a HPWH of 18 Degrees and a HPWV of 65 degrees, whilst still maintaining a very large gain vs others on the market (Combined with ultra-low VSWR for maximum power transmit and receive efficiency).
One surprising thing to note from the above picture is the ability of this unique Antenna dssign to still be able to pick up nearby hotspots in a 360 degrees radius, which is not something usually experienced or expected when using a focussed directional antenna.
This is indeed a bonus and can be seen in the picture above – this Antenna is witnessing like a combination of a traditional 360 degrees Omni Directional Antenna as well as a focussed long range Directional antenna.
Since changing from our Omni-Directional antenna in this location, it contributed to an increase in the rewards by around 30%.
Antenna Placement & Omni Directional Antenna Designs
Below, we have a hotspot using a McGill Microwave Tuned & Optimised 6dBi Omni Directional antenna located in a inner town location, at a lower height.
With slightly more obstructions nearby the antenna, a directional antenna wouldn’t achieve the witnesses to the west, north and east of the antenna’s placement. The 6dBi Omni Directional antenna therefore was a happy medium as it helped to achieve many local witnesses however still having a capability to link with many other miners in the city of Edinburgh , located some 20-25 Km away. The McGill 6dBi tuned antenna has a vertical beam width of 35 Degrees. As the antenna is an Omni Directional Design, it radiates a horizontal beam width of a full 360 Degrees.
What’s also good about the Tuned & Optimised 6dBi McGill antenna?
The McGill Microwave Tuned & Optimised 6dBi antenna is Tuned & Optimised specifically over the 868MHz frequency for EU/UK use. There is also a Tuned and optimised version available for the USA/AUS/AS/IN frequency bands here.
McGill Microwave have worked tirelessly to reduce the VSWR to the lowest in the industry, whilst maintaining exceptionally clear radiation patterns. This is only partly the reason why McGill antennas are the most sought after in the industry today. McGill Microwave test all antennas before dispatch to ensure the VSWR is under what is promised on our data sheets. Our data sheets are conservative to ensure we keep that promise for all customers.
Why is sometimes Higher dBi Better?
Since the PoCV11 changes introduced by Helium which reduced the Hotspot output power to +14 dBm in the UK/EU, McGill Microwave have experienced a significant upturn in demand for our higher gain 7.5dBi and 9dBi Tuned and Optimised Omni Directional Antennas.
With the self declared use of higher gain Antennas, the power output on helium hotspots in theory could be further reduced to meet the specified + 14dBm EIRP power level.
However, the use of higher gain antennas will increase the range of the hotspot witnessing, albeit perhaps at the cost of overshooting closer in hotspots with classical higher gain antennas manufactured by other suppliers.
Classically in radio communications, higher gain antennas are used only to cover lager distances – with no real interest in local coverage.
However, given the unique application here of Helium and the desire to connect with all hotspots irrespective of location, the McGill Microwave higher gain Antenna design are completely unique in that we have designed these antennas to push more power into the sidelobes of the main beam – giving the McGill Antennas a clear advantage in still being able to connect with hotspots much closer in, while still covering long range.
Why is Sometimes a lower dBi Better?
Lower dBi values – such as 3 dBi or 4 dBi are ideal for locations – especially those with the advantage of height- in dense urban environments where many hotspots are located in a concentrated area.
The radiated power is delivered much like a sprinkler mounted on a garden hose mounted vertically – resulting in a fairly even power distribution, albeit in a much smaller area of up to 10-15 KM’s.
Smaller gain antennas like 3 dBi or 4 dBi are typically very small antennas – for example 300 mm long – making them popular also in applications where customers don’t wish to install large size antennas in neighbourhoods where they feel may be sensitive.
They are also a popular choice for internal or external window mounting applications as an upgrade to the stock antennas supplied with the hotspot.
From the above discussion, it can be seen that, until now, there is no one obvious selection for a given location.
Testing different antennas has always been the path to optimisation and continues to be for many.
Hopefully the above article has given a basic overview to Antenna selection which the reader finds helpful.
However, there is a brand new hand held Helium Analyser field tool now available from McGill Microwave Systems which, for the very first time, now enables the user to answer the question themselves of “What’s the best antenna to use for my Helium Hotspot location”.
The Glamos Walker is specifically designed for Helium and can be used to Instantly establish what is the Best Helium Antenna to use for a given location – as well as providing a host of other valuable information and diagnostic capability when connected to the system APP.
The device has the following functionality
- Ability to connect multiple antennas to the hand held tool, one after the other and records instantly which antennas witnesses the most hotspots in your area.
- Provides the ability to send a beacon from any location and record the amount of witnesses for a given potential hotspot antenna location.
- Provides recordings of the RRSI and SNR signal levels from all hotspots which witnessed your sent beacon for a given antenna.
- Ability to troubleshoot a helium installation to verify is the antenna coaxial cable and Antenna are working – or rule out if the issue is the hotspot.
- It can record the receiving hotspots individual RSSI received power level and SNR Signal to Noise Ratio levels for a given tested Antenna.
- Establish what the best location is for a hotspot.
- Will reveal the number of hotspots which can be witnesses for a given antenna and given location.
- Can be used to align a directional antenna in azimuth and elevation to give the peak witnessing level.
All of the above information is fed back through the Helium system and into the Glamos Walker APP via the Helium console where you can display all the information. The APP also provides comparison displays of tested antennas with all data.
Still Require Help Selecting the Best Helium Antenna?
No problem, the experts are happy to help!
You can call McGill Microwave on +44(0)1592 655428 for immediate help or if you are looking to chat via email, you can email us, click the below button!