A Wideband Low-Power Balun-LNA with Feedback and Current Reuse Technique

This paper presents a low-noise amplifier (LNA) with single to differential conversion (Balun) for multi-standard radio applications. The proposed LNA combines a common-gate (CG) stage for wideband input matching and a common-source (CS) stage to cancel the noise and distortion of the CG stage. Using the proposed technique, a low noise figure (NF) is achieved while providing a wideband of operation. Furthermore, a feedback connection from the CS stage to the gate of the CG is employed to boost the transconductance of the CG stage (gm(CG)), and an additional complementary transistor is applied at the CS stage using current reuse to increase the overall transconductance of the CS stage (gm(CS)) without increasing the power consumed by the stage. This LNA was designed using TSMC 65 nm technology, and post-layout simulation results show operation across 0.5-5 GHz, a maximum power gain of 20 dB, 4 dB minimum NF, and third-order intercept point (IIP3) of -10 dBm while consuming only 5 mW of power from a 1.2 V supply.