A Wide-Swing Low-Noise Transconductance Amplifier and the Enabling of Large-Signal Handling Direct-Conversion Receivers

E. Keehr and A. Hajimiri

In this paper, the design of a wide-swing low-noise transconductance amplifier (LNTA) is presented in the context of passive mixer-based direct-conversion RF receivers, noting that the compression performance of such systems is limited by the initial voltage-to-current conversion. The proposed LNTA utilizes a stacked PMOS/NMOS common-gate configuration with its input common-mode voltage maintained by a class-AB operational transconductance amplifier (OTA). Linearization mechanisms and design procedures are explained both quantitatively and intuitively. Simulations of the LNTA at the typical corner, when ideally loaded, show an IIP3 of of