Design of a capacitor cross-coupled dual-band LNA with switched current-reuse technique

Abstract

This paper presents the design of a 2.5/3.5-GHz dual-band low-power and low-noise CMOS amplifier (LNA), which uses the capacitor cross-coupling technique and current-reuse method with four switches. The proposed LNA uses a single RF block and a broadband input stage, which is a key aspect for the easy reconfiguration of a dual-band LNA. Switching at the inter-stage and output allows for the selection of a different standard. The dual-band LNA attenuates the undesired interference of a broadband gain response circuit, which allows the linearity of the amplifier to be improved. The capacitor cross-coupled gm-boosting method improves the NF and reduces the current consumption. The proposed LNA employs a current-reused structure to decrease the total power consumption. The inter-stage and output switched resonators switch the LNA between the 2.5-GHz and 3.5-GHz bands. The proposed dual-band LNA optimises power consumption by the securing gain, noise figure and linearity. The simulated performance reveals gains of 16.7 dB and 19.6 dB, and noise figures of 3.04 dB and 2.63 dB at the two frequency bands, respectively. The linearity parameters of IIP3 are −5.7 dBm at 2.5 GHz and −9.7 dBm at 3.5 GHz. The proposed dual-band LNA consumes 5.6 mW from a 1.8 V power supply.