CMOS LNA design at 30 GHz — A case study

This paper presents a case study of LNA design at 30 GHz. Two single-stage LNA topologies are implemented, namely a magnetic feedback LNA and a cascode LNA. The simulation results reveal that a single-stage LNA can deliver adequate power gain along with low noise figure and high linearity even at mm-wave frequencies. The cascode LNA topology, using SNIM is analyzed and described in detail. The post layout simulations give a forward gain (S₂₁) of 5.9 dB, a reverse isolation (-S₁₂) of 18.1 dB, an input reflection (S₁₁) of -11.8 dB and an output reflection (S₂₂) of -11.4 dB. The NF of the circuit is 3.9 dB while the corresponding IIP3 is 4.9 dBm. The power consumption is 7.2 mW and the circuit occupies 0.37 mm² including the pads. The design is implemented in TSMC´s LP 90 nm CMOS process.