We present in this article a new model of an Automatic Gain Control for RF applications. The main feature of this AGC which is based on a MOS structure is the NMOS dynamic resistance whatever the VDS and VGS voltage are. It makes it possible to ensure a linear maximum amplification for a very low input signal and a linear minimum amplification for a high input signal, what resulting on the same output and input signal wave form. It requires much less space for its integration. The NMOS polarization is ensured by the output and the input voltage. The simulation with a sinusoidal input signal gives us a linear gain magnitude move from a maximum of 90 dB to a minimum of 0 dB for input amplitude range of  –10 mV to +10 mV.

Significant improvements could be expected with a dedicated NMOS process and design.