Basic question about functioning of CMOS RF switch

Hi All,
I have a basic question! CMOS RF switch was designed without Vd or Vs bias and connected with amplifier and it didn't work well, but it work well itself like amp only and switch only. But if they are connected, their characteristics are violated. I guess its reasons are without bias at drain and source, so there are no bias path. But why does it work well switch only? I am very curious about it!