Introduction - Choosing a 4G Antenna
No matter how good an antenna is on paper, if you choose the wrong one for your application, you simply won’t see an increase in performance. Here’s how to choose the right antenna.
Finding the Right Data Provider
Before we discuss aspects of the antenna, it’s important to make sure you’re with a network provider that offers good coverage in your area. Cellmapper is an online tool that has literally mapped all of the active cell towers (also known as ‘base stations’) in the developed world and it’s perfect for this stage of the process.
Use Cellmapper to identify which suppliers provide the best coverage for your area. This way, you’re ensuring there’s at least a decent signal being broadcast for your antenna to pick up in the first place.
You can always change your supplier at a later date if things don’t work out, so if you’ve already purchased a data SIM or would like to test out a configuration before committing to a new provider, you’ll be able to do that and switch later if you need to.
Finding the right data provider and locating your local masts are important parts of the antenna buying process.
Omni vs Directional Antennas
Now that you know which provider you’ll be going with, it’s time to determine exactly what type of antenna is best suited for your purposes and your location, since environmental factors can heavily impact the end performance you get from your antenna. These will dictate whether you want to choose a directional or omnidirectional antenna.
In short, if you live in an urban area, an omnidirectional antenna will serve you best. This is also true if you’re looking to attach your antenna to a mobile home, boat or other ‘moving target’. If you live in a more rural area, a directional antenna would be preferable.
In urban areas, direct line of sight to your local cell mast is much more difficult to achieve since there are more buildings getting in the way. Signals from the cellular base station will reflect off of buildings in an unpredictable manner, making orienting the antenna to ‘catch’ these reflections almost impossible. Plus, if you’re a moving target, orienting an antenna toward a fixed point won’t help since your location will change relative to the base station as you move. An omnidirectional antenna, for which orientation need not be considered, solves these problems.
If you live in a rural area, it’s more likely that there will be fewer base stations, meaning the probability is higher that you’ll be situated further from any given base station. What’s more, rural areas tend to have fewer obstructions, making line of sight to the cell mast much easier to achieve. These factors make directional antennas preferable. By radiating RF energy in a narrow, concentrated beam, a directional antenna is very effective at long range, though it needs to be oriented carefully, pointing right at the base station with a direct line of sight. For these reasons, directional antennas are perfectly suited for the rural environment where the distance between you and the cell mast is often greater and tall obstructions are fewer and far between.
A yagi-style antenna like this one will radiate RF energy in a highly directional, focussed beam.
Supported Frequencies
Whether you’re looking for a 5G-ready LTE antenna, a WiFi antenna, or one that supports GPS, it’s important to take note of the frequencies supported by your antenna.
Wide-band antennas are available, which cover many or even all of the most commonly used frequencies but, for the most cost-effective solution, it’s best to identify exactly which frequency bands you need your antenna to take care of and purchase an antenna that services only these frequencies.
Poynting’s XPOL-2-5G, for example, is an LTE antenna servicing 3G, 4G and the new 5G frequency bands, but does not cover WiFi frequency bands.
In the UK, you won’t find any frequencies being used below 800MHz, whilst in Norway, the 400-450MHz band is used for 4G.
For obvious reasons, depending on where you are, who your provider is and your requirements, it’s crucial that you’re aware of which bands your antenna needs to cover before purchasing.
The graph above shows that Poynting's OMNI-291 supports lte frequencies ranging from 450MHz-2.7GHz.
Antenna Gain vs Radiation Patterns
Now it’s time to begin comparing antenna models and objectively determining their level of performance. To do this, we need to understand two key components: an antenna’s gain and its radiation pattern.
For a detailed look into radiation patterns and why they’re more important than they’re often given credit for, you can read our dedicated article on antenna radiation patterns.
Radiation patterns are often difficult to understand. They can’t be seen and aren’t as easy to market as the purely numeric, ‘higher is better’ strategy used with antenna gain.
Unfortunately, this often leads to poor product choices by consumers, since a poor radiation pattern cannot be compensated for by high antenna gain. In short, an antenna’s radiation pattern determines the shape of the field in which the antenna can effectively receive and send RF energy. If an antenna radiates energy up to the sky or down to the ground, rather than in the intended direction, towards the horizon, higher gain will simply push the field further out in these useless directions. And this is more common than you’d think, especially in poorly made antennas.
Poynting publishes the radiation patterns for all of their antennas and are renowned for their excellent radiation patterns. You can browse Poynting antennas and review their radiation patterns at NetXL.com.
Radiation patterns for Poynting's OMNI-291 in the elevation plane. RF energy is efficiently distributed toward the horizon.
When it Comes to Antennas, Bigger is Better
When it comes to the physics of an antenna, a smaller antenna is simply not going to be as capable as a larger one.
If you want the best performance possible, two antennas that look similar in performance on paper will be separated in practice by their size, so consider whether a large antenna or a smaller antenna is more appropriate for your use case.
Are aesthetics important to you, or does performance trump everything else?
An antenna like Poynting’s PUCK-2, for example, is small and unobtrusive, whilst a larger antenna like the OMNI-291 will stand out, but will supply excellent omnidirectional performance.
Antenna IP rating
The IP rating of any piece of equipment denotes its level of protection against water and dust ingress, as well as temperature resilience. Generally, the higher the IP rating the better if your antenna is going to be exposed to the elements at all.
An antenna that’s going to be mounted on the outside of your house will need to be weather resistant with an IP rating of IP65, whilst an antenna that’s going to be used on a sailboat or in other harsh conditions will need to be highly resistant to water and corrosion and will need an IP rating of IP68.
Be sure to consider what you’ll be using your antenna for and what kinds of conditions it will be subjected to before choosing a product with an appropriate IP rating.
Poynting's Puck 2 is a small, robust antenna with high IP and IK ratings, making it perfect for IoT and automotive applications.
IK Rating
Whilst IP rating classifies protection against water and dust, an IK rating classifies impact protection and resistance to shocks and vibrations. If you intend to use your antenna in a transportation or IoT application where it could receive a few knocks, or in stormy seas where it could be impacted by heavy waves, you’ll want to check its IK rating for confidence that the build quality will stand up to this rougher kind of treatment. Alternatively, if the antenna is going to be placed somewhere easily accessible to the public, it could be prudent to choose a vandal-resistant antenna like Poynting’s PUCK range.
Conclusion
Buying an antenna can be an intimidating process for the uninitiated. Hopefully, this guide has given you a firm grasp of what should be considered before you part with your money. In short, consider each of the above factors before buying so you can be sure your antenna will provide you with the desired increase in performance.
Don’t forget - you can purchase all of the products mentioned in this article with us at NetXL. If you have any more questions, our support team are more than happy to help, so give us a call and we’ll be happy to assist you.
