A 28-GHz CMOS LNA with Stability-Enhanced G_m-Boosting Technique Using Transformers

Abstract

In this paper, we propose a low noise amplifier (LNA) using a g <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</sub> -boosting technique with improved stability using transformers in the millimeter-wave (mm-Wave) band. The transformer composed of three inductors improves not only stability, but also gain and low-noise performance of the LNA. The conditions for stability shows that the proposed structure can guarantee good stability over a high frequency range. The chip was fabricated using the TSMC 65-nm CMOS process and it has an active chip area of 0.11 μm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . The fabricated LNA has a gain of 18.33 dB and a noise figure (NF) of 3.25-4.2 dB. The stability factor μ values are 9.7 and 5.2 at the source and load sides of the LNA, respectively. The 3-dB bandwidth of the LNA is 24.9-32.5 GHz and the chip consumes 17.1-mA current from a 1.2-V supply.