A Low-Noise Amplifier Utilizing Current-Reuse Technique and Active Shunt Feedback for MedRadio Band Applications

Abstract

In this work, a low-power 0.18-μm CMOS low-noise amplifier (LNA) for MedRadio applications has been designed and verified. Cadence IC5 software with Silterra’s C18G CMOS Process Design Kit were used for all design and simulation work. This LNA utilizes complementary common-source current-reuse topology and subthreshold biasing to achieve low-power operation with simultaneous high gain and low noise figure. An active shunt feedback circuit is used as input matching network to provide a suitable input return loss. For test and measurement purpose, an output buffer was designed and integrated with this LNA. Inductorless design approach of this LNA, together with the use of MOSCAPs as capacitors, help to minimize the die size. On post-layout simulations with LNA die area of 0.06 mm2 and simulated total DC power consumption of 0.5 mW, all targeted specifications are met. The simulated gain, input return loss and noise figure of this LNA are 16.3 dB, 10.1 dB and 4.9 dB respectively throughout the MedRadio frequency range. For linearity, the simulated input-referred P1dB of this LNA is -26.7 dBm while its simulated IIP3 is -18.6 dBm. Overall, the post-layout simulated performance of this proposed LNA is fairly comparable to some current state-of-the-art LNAs for MedRadio applications. The small die area of this proposed LNA is a significant improvement in comparison to those of the previously reported MedRadio LNAs.