At the beginning it’s important to determine the definition of X-polarity. In our case X-polarity is slant +/- 45 deg polarization, so simply speaking means MIMO antenna rotated of 45 deg. This technique is used for example in 3x3 and 4x4 antennas in 802.11n standard or in more complex standards as 802.11ac.
Rotating the antenna we got new polarizations, different from common-used H and V. It enables possibility to create more efficient links which are less interfered by neighbour networks working in H&V polarizations. In very noisy enviroments it makes antenna operation better and more efficient. Due to different polarization the user can install antennas in occupied frequencies in very crowded locations.
The main goal of this project was to separate data streams in the MIMO connections in possible high level. This is used mainly for 3x3 links, where signal streams are maximally separated to achieve max throughput. See the graphical illustration (Pic. 1) of polarizations, including X-Pol (H-45 and H+45 slant)
Pic. 1 Graphical illustration of X-Polarity H-45 and H+45 slant polarizations in WiBOX Extra Large example.
This is the normal 802.11n system or some modification like wider channels on MikroTik (read the client story Can You imagine link over 300 Mbps with RouterBoard and MIMO 2x2 antenna ? ). Our antennas work in MIMO system as normal H&V antennas, but requires also X-Pol antenna on both sides of the link. The quality of antenna operation depends on the quality of another antennas installed in the naighbourhood and their polarization separation. That system works with single and dual chain interfaces provided by manufacturers like MikroTik or UBIQUITI.
MIMO X-polarity antennas are less sensitive for interferences than standard H&V MIMO antennas, because there is not a lot of station using that polarities in the enviroment.
Using X-pol antennas, the user needs to know how to install these antennas (more about installation of H&V&X-pol systems you can see How to connect antennas of WiBOX SA D4M5-90-17HVX, WiBOX PA D4M5-20HVX and WiBOX PA D4M6-20HVX in MIMO 3x3 and MIMO 4x4 configurations).
Wireless Instruments used X-pol in few antennas:
Any questions, write to us: info@wireless-instruments.com
