A CMOS Single-Ended to Differential LNA with Notch Filter for Beidou Satellite Communication Applications

Abstract

A single-ended to differential low noise amplifier (LNA) for Beidou satellite communication applications based on standard 40 nm RFCMOS technology is reported. On-chip L-C parallel tank load and source degenerated inductor are used in the first-stage single-ended amplifier to reduce the influence of TX leakage signal on the input of LNA. The pseudo-differential cascode amplifier with an inductor as tail current source and 4-terminal symmetric mode octangle inductor as load are adopted in the second-stage to output differential signals and achieve sufficient gain. The two-stage differential series-parallel L-C notch filters are respectively added to the differential common-source output and the common-gate output to suppress the strong TX interference signal. The simulation results show that the LNA achieves S21 18.2dB, NF 2.2dB, and S11 -11. 5dB at 2.491GHz. The interference signal rejection ratio is 44.8dB at 1.6GHz. The static power consumption is only 6.16mW with a size of 1.931 × 1.332 mm² including testing pads.