A 33-GHz LNA for 5G Wireless Systems in 28-nm Bulk CMOS

This brief presents a design procedure of a compact 33-GHz low-noise amplifier (LNA) for fifth generation (5G) applications realized in 28-nm LP CMOS. Based on the unique set of challenges presented by advanced nanoscale CMOS, the emphasis is put here on the optimization of design and layout techniques for active and passive components in the presence of rigorous metal density rules and other back-end-of-the-line challenges. All passive components are designed and optimized with full-wave electromagnetic simulations for a high quality factor. In addition, layout techniques help to miniaturize the total area as the suggested 5G frequency band of 33 GHz is not high enough to provide a sufficiently compact chip size. The resulting increase in the concentration of required metal fills furthermore makes this optimization more challenging. The fabricated LNA consists of two cascode stages with a total core area of 0.68 × 0.34 mm². It exhibits 4.9-dB noise figure and 18.6-dB gain at 33 GHz while consuming only 9.7 mW from a 1.2-V power supply.