It doesn't help if you don't tell us exactly which model number is the atheros chipset inside the dongle. Better yet, FCC id of the device.
As for atheros USB support, chances are at getting it to work with monitor/injection are very bleak. Atheros acquired Zydas which I believe gave Atheros the opportunity to expand into wireless USB capability. The initial chipset, Atheros AR5007UG is rumoured to be a rebranded Zydas ZD1211B chipset which does somewhat has linux support and since then Atheros has not been open in the later versions of their USB chipsets until 802.11 Draft N (which is now 802.11N). There's a very likely chance that your chipset does not have native linux support which is mandatory for monitor mode and injection is dependent on monitor mode which again requires native linux driver support.



