In this paper, we report a detailed study of the negative capacitance field effect transistor (NCFET). We present the condition for the stabilization of the negative capacitance to achieve the voltage amplification across the active layer. The theory is based on Landauʼs theory of ferroelectrics combined with the surface potential model in all regimes of operation. We demonstrate the validity of the presented theory on experimental NCFETs using a gate stack made of P(VDF-TrFE) and SiO2. The proposed analytical modeling shows good agreement with experimental data.