An awful lot of newly established wireless networks nowadays are highly dependent on MIMO antennas. MIMO stands for Multiple-Input-Multiple-Output. This technology boasts of taking wireless performance of devices to a heightened level of efficiency and reliability. However, much like every other system we have in the modern world, this one has its own share of weak points. We are going to show you here now some of the most common pitfalls linked to the use and selection of MIMO antennas.
The process of choosing the most appropriate antenna for your application can never be qualified as a trivial undertaking. While system designs are closing in to their full completion, the idea about the use of antenna comes to mind. System designers are always in high anticipation of the gains they need to obtain from the antenna, after which they’d go about and shop around looking for any reasonably priced antenna. They sometimes fall on a whim of looking for an antenna based only on its cool factor or good aesthetics, oblivious of the requirements that it requires.
With regard to the conventional single communications channel, the quarter-wave and half-wave antennas are understood really. The peak current of standard half-wave antenna is in the middle, while the peak voltage can be found at its end. The center’s peak current is considered very handy due to the antenna’s extremely low impedance and the perfect spot for antenna feeding using transmission lines of 50 Ohm. We call half-wave antennas dipoles, and we qualify them as plane ground independent.
In a basic quarter-wave antenna, voltage peaks can have a one-quarter wavelength from its feed point. This makes the ground plane dimension to be at least a quarter wave long to allow a properly balanced antenna. Quarter-wave antennas are ground plane dependent and we call them monopoles.
Usually, a half-wave design will not be needing an additional ground plane. Therefore, if you make an effort to attach that to an access point plastic enclosure, it will not affect its performance. And for this reason, the system designer is likely to witness his expected performance.
If a system designer decided to have a quarter-wave design and have that on the exact, same plastic enclosure, he is up for some surprise that the performance he is anticipating to see is lower than what he is expecting. A simple type of quarter-wave antenna needs to work against a ground plane.
In the case of access point plastic enclosure, there is no metal intended for the quarter-wave. Hence, you can substitute internal components for a ground plane. This may induce the RF current to be possibly seen in any metal that is within its reach, such as the power supply leads.
If, from the very start, the system designer knew already that a quarter-wave antenna is the best choice for his access, more targeted steps could have been utilized while still in the design stages.
Metalization in the plastic enclosed unit could have been utilized instead. It would provide the plane ground of the antenna electronic shielding. The main circuit board also could be designed to work as the ground plane without the need to create an impact on the other electronics, which is done typically in cellular or mobile phones.