Design of Low Power 2.4GHz CMOS Cascode LNA with Reduced Noise Figure for WSN Applications

Abstract

In this paper, a narrowband cascode Low Noise Amplifier (LNA) with shunt feedback is proposed. A typical inductively degenerated cascode LNA can be treated as a Common Source-Common Gate (CS-CG) two stage LNA. The series interstage inductance is connected between CS-CG stages to increase the power gain. An additional inductance which is connected at the gate of CG stage is used to cancel out the parasitic capacitance of CG stage therefore reduces the noise figure of CG stage. The shunt feedback is used to improve the stability and input impedance matching. This configuration provides better input matching, lower noise figure, low power consumption and good reverse isolation. The proposed LNA exhibits the gain of 13 dB, input return loss of ?11 dB, noise figure of 2.2 dB and good reverse isolation of ?42.8 dB at a frequency of 2.4GHz using TSMC 0.13 μm CMOS technology. It produces gain and noise figure better than conventional cascode LNA. The proposed LNA is biased in moderate inversion region for achieving sufficient gain with low power consumption of 1.5mW at a supply voltage of 1.5V.