Consideration of Linearity in Cascode Low Noise Amplifiers using Double Derivative Superposition Method with a Tuned Inductor

In this paper, we propose a highly linear low noise amplifier (LNA) using the double derivative superposition method with a tuned inductor. This topology has an auxiliary common gate stage of the cascode amplifier to cancel each third order intermodulation distortion (IMD3) component and can provide a high third order input intercept point (IIP3) for the 5.25 GHz frequency band. From the simulation results using the TSMC 0.18 mum RF CMOS process, the IIP3 in the proposed cascode LNAs can be improved by 9 dB, compared with the conventional derivative superposition method. The proposed low noise amplifier achieves an IIP3 of +15 dBm with a gain of 10.5 dB, a noise figure (NF) of 2.4 dB, and a power consumption of 6 mA at 1.5 V.