A Methodology for the Design of Capacitive Feedback LNAs based on the gm/ID Characteristic

Abstract

This paper presents a $g_{n}\sqrt {}I_{D}$ based design methodology for a capacitive feedback LNA topology. The proposed method gives the optimal value of $g_{n}\sqrt {}I_{D}$ to achieve the required performances (Gain and Noise Figure) while ensuring the minimum consumption. Moreover, it makes possible the sizing of all the components of the structure with a degree of freedom for the inductance value needed for the input power matching. This methodology is illustrated through the design of a $2. 4\mathrm {G}\mathrm {H}\mathrm {z}$ LNA in the $28\mathrm {n}\mathrm {m}$ FDSOI technology from ST-Microelectronics.