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

In this paper, we propose a low noise amplifier (LNA) using a g m -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 µm2. 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.