Sidechain gate

I want to use a side chain for kick and bass, so they are heared and silence on the same moment.

Currently only sidechain compression exists, but then the oposite happens: bass is silence when kick is heard and in the silent parts of the kick, then the bass is heard. It must be the other way.

Gate could be a solution, but there is no Sidechain option for it.

Anybody?