A Deep Notch Filtering LNA with Compact Layout and 2.3 dB NF for Ka-Band Satellite Communication

This paper presents a 4-stage single-ended Ka-Band LNA with shunt-series LC-based notch filter. The series resonant LC-tank in the filter is stacked onto the shunt part, leading to compact layout. Magnetic and electrical feedforwards are introduced in the conventional gm-boosting common gate input stage for better noise and gain performance. The drain inductor in input stage and the series inductor in the notch filters are twisted to 8-shape to obtain controllable low magnetic coupling. The LNA is fabricated in 65-nm CMOS process and occupies an area of 375 μm × 930 μm including all pads. The chip consumes 26.8 mW from a 1.2 V supply and achieves a measured peak output-referred 1-dB compression point (OP1dB) of 6.4 dBm. The measurement result shows a 62 dB notch depth with a 3-dB bandwidth of 27.5-29.7 GHz and a minimum noise figure of 2.3 dB.