Abstract: Solid state plasma channel (SSPC) antenna based on PIN diodes owns many excellent performances, such as ultra-wide band, cloaking, and multifunction, and has attracted many attentions in the communication field. In this paper, we systematically study this SSPC in theory, including the channel formation mechanism, the free charge carrier concentration and distribution and the equivalent refractive index under different conditions. And the related analytical solutions have been given out. The research results show that the charge carriers with high density and uniform distribution can be achieved in SSPC under certain conditions, and then high frequency electromagnetic signals can be efficiently transmitted. The FEM simulation results show that this channel can be used as antenna effectively. These research results will further promote our understanding on the SSPC and provide important theoretical guidance for the related antenna design and fabrication.