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.