Question about using 2 antennas on a mini-pci card?

Hi, let’s say I’ve got a 24 Mbps Wi-Fi link. If I use only one antenna realistic speed will be around ~12 Mbps.
But there’s an option in Wi-Fi part. If I use antenna a(main) as a RX and use antenna b(aux) as a TX in both sides(as a backhaul). Will that realistic speed will be around ~24 Mbps?

No, it will not give you 24Mbps, one wireless card will always give you half-duplex communications.
Two antennas on one wireless card doesn’t give any advantage, if you compare it to one antenna system.

You can get 24Mbps, when two wireless cards are used together with Dual Nstreme.

Can I use 3 Mini-pci card, so I can get 3/2 x 24Mbps ~ 36 Mbps real througput. I wonder if RB433 can handle 162 Mbps?(3/2 x 108 mbps ~ 162 Mbps) I wonder if can handle Max. speed.

Nstreme-dual only works with one pair of cards. One for transmit, one for receive.

Instead of using 2 channels at same time, with nstreme2, I can use only 1 band to get full performance. Nice.
Other question is what’s the Rb433’s max. throughput in wireless?

There is no wireless specific throughput limit. The throughput will be only limited by CPU power, and those tests you can see here: http://www.routerboard.com/pdf/tests_july_2008.pdf

also of course there will be wireless protocol limitations, physical and environmental limitations.

it says 197 mbps??? So cpu can handle 197 mbps?(I think that is Ethernet limitation because 2 ethernet ports used)
So it can handle right?

yes, wireless 802.11abg standards have their own speed limitations