A 24–30 GHz CMOS LNA with 2.05dB NF and 0.6dB in-band gain ripple for 5G-applications

This paper presents a low noise amplifier (LNA) for 28 GHz communication system of 5G-applications. The proposed LNA composes of three differential amplifier stages. A common-gate stage acts as the first one for broadband input impedance matching and two cascode stages followed for a higher gain. In order to reduce the noise and improve the gain, the gm-boost technique based on capacitor cross-coupled is employed. Besides, parallel-LC matching network is applied at the output to reduce the return loss. Furthermore, the peak gain of each stage is separated and tuned respectively for a flat gain. This LNA is designed and simulated utilizing 65 nm CMOS process. The post-layout simulation shows that a gain of 30.5 dB with ±0.3 dB gain ripple in 24-30 GHz and a minimum noise figure (NF) of 2.05 dB at 25.5 GHz are achieved. The proposed differential LNA dissipates 30 mW with a 1 V power supply.