Atheros ar9285 wifi adapter is not working in macOS Mojave it got removed from macOS Mojave is mostly because of the fewer features and but here is I’m going to share a trick to work Atheros ar 9285 in macOS Mojave.
We know that it is working in macOS high sierra because of IO80211Familly.kext is available in /System/Library/Extensions Folder but it got removed for macOS Mojave.
We going to use this driver in macOS Mojave open kext as show package content click on contents then click on Plugins and in the plugins folder you will get kext AirPortAtheros40.kext. simply copy AirPortAtheros40.kext.
Navigate to the menu bar and in and click on go here you need to access folder /Library/Extensions After that paste the kext here now open the terminal and copy this command and paste into the terminal to fix and rebuild caches.
sudo chown -R root:wheel /L*/E*; sudo chmod -R 755 /L*/E*; sudo kextcache -i /
it will take some time to complete this process once it completed then Reboot and see if it works. I have tested in my Dell Latitude E 6420 and it working just like working in macOS High Sierra.
Download your driver/kext from here