Are you finding it difficult to figure out which antenna you need to buy? It isn’t as simple as just picking the one with the best performance, or the highest price point – but actually finding one that fits your specific needs and requirements.
How do you do that? Well, a good place to start is by looking at these five factors:
The fit of the antenna includes its form and type. It is important to determine whether how the antenna will be placed, what size it can be, whether it needs to be mounted, the type of mounting that is required, and so on.
For example in some cases you may need a compact antenna that can be embedded inside a device. In others, a larger antenna that is going to be temporarily mounted may fit better.
Different antennas are tuned to different frequencies – so you need to make sure you look for those that match the frequencies you intend to work with. Typically the frequencies you choose will be based on the standards of the wireless technologies (such as Iridium, WiFi, 3G, 4G, etc.) that need to be used and whether you’re looking at single or multi-band coverage.
It should be noted that having a wider bandwidth may affect the performance of the antenna in other ways. Because of that if it isn’t necessary it is best to choose an antenna designed solely for the range you need.
Broadly speaking antennas can either be directional and focused in a specific directional, or omnidirectional and focused in all directions. The increase in signal is the ‘gain’ of the antenna, and the higher it is the more focused and directional the beam will be.
Simply put if you want to broadcast in a fixed direction then a high gain antenna can increase the effective signal coverage. However if you want to broadcast evenly then you don’t want your antenna to have much gain.
Always remember that the antenna is just part of a whole, and you need to look at how it affects the rest of the circuit. More specifically the impedance needs to be aligned – typically to 50 ohms.
Based on the impedance requirements you can then look at the type of connector that you would like to use. It is best to stick to the more popular types of connectors based on the application of the antenna, such as SMA, UHF, or U.FL.
The best way to measure an antennas actual performance is via its efficiency – which is the amount of power supplied to the antenna that is actually transmitted. The antenna efficiency itself hinges on various factors including its placement, ground plane length, impedances, and so on.
When you choose an antenna you should aim for as high an efficiency as possible in relation to its practical use. It can make a world of difference to the longevity of battery-powered devices, and overall energy consumption.
If you take into account these five factors, you should be able to easily narrow down the range of antennas that you’re looking at and identify those the fit best. In the event that you still have difficulty you should try to take a step back and define requirements that are more specific.
Although it may be a bit confusing and could take up some time – selecting the right antenna will definitely pay off in the long term. It will ensure that you end up with one that delivers the performance that you expect, and integrates into your design effectively.