A 2.4-㎓ Low-power Low-IF Receiver Employing a Quadrature Low-noise Amplifier for Bluetooth Low Energy Applications

Abstract

In this paper, a low-power low-IF receiver employing a quadrature low-noise amplifier (LNA) is proposed for Bluetooth low energy (BLE) applications. The proposed quadrature LNA, which can provide accurate quadrature signals in the RF path, consists of a common-source amplifier with inductive degeneration and a quadrature generator based on a common-gate amplifier with a single RC network. Therefore, a BLE receiver using the proposed LNA can eliminate quadrature generating circuitry of the LO chain, thereby reducing power consumption. The implemented receiver is composed of the quadrature LNA, single-to-differential double-balanced active mixer, and second-order G<SUB>m-</SUB>C complex filter. Simulated in a 65-nm CMOS process, it achieves a conversion gain, noise figure, and an image rejection ratio of 53.2 dB, 4.81 dB and 38 dB, respectively, and consumes 2.2 mA from a supply voltage of 0.8 V. The die area is 2.24 ㎟.