As a companion to our 4G Router review, the following provides further information regarding the use of external antennas with 4G / LTE desktop routers.
Some ISPs are now offering 4G based home broadband with unlimited data allowances. This finally makes doing away with Fibre optic FTTC/FTTP connections and the associated line rental costs a realistic option.
If you don’t want to pay for a telephone line that you never actually use, and can live with speeds that are probably not quite at the level of a good fibre connection, 4G (or 5G in the near future) is well worth considering.
If you go this route, teaming an external antenna with a good quality 4G router will give the best chance of success.
OMNI vs Directional
For most uses, an Omni-Directional antenna will be best. Are you looking to mount your antenna at a fixed permanent location, and do you know where the nearest mast is and is there a direct line of sight between you and the cellular mast? Unless you can answer “yes” to all these question then an Omni is probably the type to go for.
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In urban areas you will mostly like be in range of several masts so the Omni will win here as it can receieve from all directions. Also in built up areas it can be impossible to actually get a line of sight to a mast due to there being buildings or other obstacles blocking the path.
Directional antennas need to be pointed towards the nearest tower or mast. An Omni-directional antenna doesn’t have to be aimed as it picks up signals from all directions. While a directional antenna might seem like the best idea, there are several potential problems…
UK Frequency Range
Most antennas cover the full range of frequencies you will need to pick up. The UK 4G providers use different frequency bands from each other. Check the table below to see which bands are used by your chosen service provider.
Single vs MIMO
Back in the days of 3G, an antenna with a single output was fine. Nowadays with 4G coverage pretty much everywhere, you should ensure the antenna you buy is a MIMO (Multi Input, Multi Output) type. This is reflected in the fact that in 2019 pretty much all antennas for sale are MIMO.
One of the main reasons that 4G is faster than 3G is because it allows combining two or more antennas to increase performance.
All LTE / 4G routers should have two antenna connectors on the back. To achieve their full potential you need to use both ports. This can be achieved by either buying two identical antennas, or buying a MIMO unit which will already have two antennas mounted within one casing. The clue here is that they’ll have 2 cables coming from within the antenna.
The video below explains this further.
This is quite important and is an area where an external antenna can actually make things worse. Unlike a routers built in antenna, the signal from an external antenna will probably have to travel down 2 to 5 metre long cable(s). The longer the cable, the more signal strength will be lost. If you are already receiving a strong signal then the built in antennas may in fact pickup a better signal.
External antennas are best for cases where the router struggles to pick up a signal. Here, an external antenna that can be mounted outdoors and several metres higher will stand a much better chance. Due to lack of walls and other obstacles, the external antenna should provide better performance even taking signal loss down it’s cables into consideration.
Most 4G routers will use either SMA or TS9 ports, with SMA probably the more common. Just be sure to check which ports your router has before you buy.
As mentioned above, most routers use SMA connectors. However, don’t worry if find an antenna you like the look but it has a different style of connectors to that of your router, as SMA to TS9 convertors are available.
An easy first step would be to try an omni-directional antenna from somewhere like eBay. This was what I started with in 2015, and there are plenty of similar models available for around £20. The come with two emtres of cable and a suction mount
Being able to use the suction mount to position the aerial high up in a window was a vast improvement as you can see below. At the time 4G was not yet available, but where as before 3G would only offer 1-2 Mbps download, with the aerial in the window I got nearly 10 Mbps down (and nearly 2Mbps upload).
I stuck with this setup for several months, but then decided to splash out on the Poynting XPOL-1 which is a more robust version. The main reason for this was that the eBay antenna only has a suction mount so had to stay inside, in a window. The Poynting also includes fittings to mount on a 1-2” diameter pole. This meant it could be placed higher, above the roof, for hopefully an even better signal.
In the mean time 4G had become available in my area. As you can see, raising the antenna by around 3 feet almost doubled my download and upload speeds.
4G speeds showing the improvement from pole mount antenna…
In summary, the Poynting is better built and comes with 5 metres of (thicker) cable compared to the eBay version with only 2 metres. However, the speed and signal strength when mounted in the same position was around the same on both antennas.
The Poynting XPOL-1 justifies its higher price by being able to be pole-mounted and so can pick up a stronger signal.