the 1141 is a single radio AP. If you need the 5GHz, you need to order teh 1142N.
For the N / High throughput rates you have to either configure WPA2/AES or Open as the encryption, WMM must be allowed. That is per spec.
It is not normally recommended to do a channel bond on the 2.4Ghz as there are only 3 non-overlapping channels. But you may be able to do so, if this is your only AP. If you have more than one AP, then you will not be able to do this without significant RF complications
HTH,
Steve
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