A 20 GHz 1.9 dB NF LNA with distributed notch filtering for VSAT applications

This paper presents a 20 GHz low noise amplifier (LNA) with notch filtering from 27.5 GHz to 31 GHz in a 0.25 μm SiGe:C BiCMOS technology. Notch filters are proposed to be implemented at different stages to have minor impact on the noise figure (NF), while achieving high attenuation around 30 GHz. In comparison with a reference LNA without filtering, it achieves overall filtering of more than -30 dB from 27.5 GHz to 31 GHz, with a NF of 1.9 dB degraded by only 0.1 dB to 0.4 dB. More than 17 dB improvement is achieved on the gain compression and triple beat IIP3 in presence of high power blocker. Besides, both LNA´s achieve best NF to-date with high overall performance at K-band in silicon technologies.