Rb600 & mimo card (WLM200N5-26)(please help)

I have a link (It,s in lab now ). my RB is RB600 and my card is WLM200N5-26 compex.
please tell me ,how can I use it for a big bandwidth?

I config like below:
mode: bridge
band: 5GHz-only-N & frequency:(ex : 5200)
in HT tab :
all HT tx & rx is checked;
HT guard:long
HT extension channel: below control
HT AMPDU: I checked only 0
HT CMS is deactive(how can I active it?)

with this config I only get maximum bandwidth is 30mhz
and dBm is -50
and data rate for tx : 117 rx: only 6mbps
please tell me what is problem.
thanks

Do you have both chains enabled for ht-rxchains/ht-txchains?
Information abou 802.11n configuration parameters is here,
http://wiki.mikrotik.com/wiki/802.11n_Setup_Guide