The key thing is wifi antenna are required to have the same physical connectors. This was done originally by the fcc to discourage use of antenna that allowed the effective output power to be too high. You now find lots of antenna that are technically illegal to use but have the proper connectors. Most are 5db , don't buy above say 9db. The problem is the antenna is also increasing the levels of the background noise and if you get it too high it overloads the amplifier and larger antenna can be slower.