Here is how to get the driver working on different operating systems.
The card connects only at 65 Mbps or 144 Mbps instead of 300 Mbps; the 5 GHz network is invisible. Atheros Ar5b22 Driver
Because Qualcomm Atheros was acquired by various companies over the years (and the chipset is considered "Legacy" or "End of Life"), the official support pages are often fragmented or difficult to navigate. Here is how to get the driver working
lspci -nn | grep Atheros