[QUOTE=TheSkyIsFalling;55390In my opinion it sounds quite stupid to use two separate antennas for the systems which operate in the same frequency... [/QUOTE]

Actually, it's somewhat clever. This approach is called "diversity reception," and depending on how it's implemented, is something as simple as selecting the antenna that has the stronger signal strength to something called "maximum ratio combining" where the two signals are summed together in a special way (this is actually the precursor of MIMO systems). Diversity reception has been around for decades -- and is pretty much ubiquitous in all laptops today for WiFi. It significantly improves the average signal strength a device receives, particularly when the devices is in motion: Just walking around often creates short-term fading in one antenna that can easily reduce its output to 1/100 or even 1/1000 or the typical signal strength; having a second antenna that's in a different location gives you a very good chance that at least one of the antennas is still getting a decent signal.

---Joel