Wideband dual‐mode complementary metal–oxide–semiconductor receiver

Abstract

A dual-mode complementary metal–oxide–semiconductor (CMOS) receiver operating from 1 to 2 GHz is presented. The proposed receiver employs a switchable low-noise amplifier (LNA) and two separated down-conversion paths to realise dual-mode operation. For receiving weak signals without large blockers, the receiver works in the high-gain mode which adopts the common gate (CG)–common source (CS) LNA and the active-mixer-based down-conversion path to achieve high gain and low noise figure (NF). In the case of large in-band blockers, the receiver works in the high linearity mode, which uses the LNA as a low-noise transimpedance amplifier followed by a 25% duty-cycle current-driving passive mixer and a transimpedance amplifier based on current buffer to obtain high in-band linearity. Implemented in a 0.18 μm CMOS technology, this receiver achieves 4.9 dB NF and a voltage gain range of 29.4–92.6 dB in high-gain mode, whereas +0.9 dBm in-band input-referred third-order interception and a voltage gain range of 15.8–20.1 dB in high linearity mode.