Quoting mcintire, reply 54If it's "just a few squads" I would again like to point you to strikecraft upgrades. Seriously, even if you put 7 bomber-/7 fightersquads on a starbase it's still enough to fend of a group of support carriers and kill the carriers themsleves, no matter where in the well they are.
Fend of the carriers yes, but not a large (not huge) fleet of standard frigates.
Don't the standard frigates have to get into attack range of the starbase to do anything efficient? They'd get chewed up by the regular guns leaving behind the carriers, or they would stay at the edge of the well with the carriers doing nothing. "Worst case", both sides have a number of AA frigates/structures that just cancel out each others' bombers, which can be solved by sending in a proper fleet to clean up.
I'm not a fan of the weapon bristling behemoth type of lategame ships and or structures. They tend to make the game repetetive, I'm not sure giving the starbases AA will have a different effect.