Multiple-in/Multiple-out Antennas (MIMO) Explained
Most antennas work very simply: a frequency transmitted from one antenna could be picked up by a antenna tuned to receive it a distance away without the need of cables between them. While this basic description of a wireless system works, today we have many ways to improve upon the basic concept to increase things like redundancy and coverage. One of those methods is MIMO, which stands for multiple-in multiple-out.
MIMO antennas are actually several antennas all within a single physical radome. They co-exist either by working in different bands (as the IEEE standard 802.11n works, in both 2.4 GHz Wi-Fi and 5.8 GHz) or different polarities, or both. By breaking the data into separate signals and broadcasting them over multiple antennas, MIMO systems can pick from the strongest signal no matter what the environmental conditions.
If you have a radio, access point, router or other wireless device that uses MIMO transmission, you will usually see separate jacks for the different signals. Likewise, a MIMO antenna will have multiple jacks or cables to hook up. Once they are plugged in, the antenna takes advantage of a phenomenon called "multipath", which refers to the way multiple signals bounce off of objects and arrive at the receiver at slightly different times.
Quick note: L-com's MIMO antenna product center includes options for many popular bands and antenna types.