A 1-V 5-GHz Self-Bias Folded-Switch Mixer in 90-nm CMOS for WLAN Receiver

Abstract

A 5 GHz double balanced mixer (DBM) is implemented in standard 90 nm CMOS low-power technology. A novel low-voltage self-bias current reuse technique is proposed in the RF transconductance stage to obtain better third-order intermodulation intercept point (IIP <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> ) and conversion gain (CG) when considering the process variations. The DBM achieves a CG of 12 dB, a noise figure (NF) of 10.6 dB and port-to-port isolations of better than 50 dB. The input second-order (IIP <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) and IIP <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> are 48 dBm and 4 dBm, respectively. Two I/Q DBMs are then integrated with a differential low-noise amplifier (DLNA) and a poly-phase filter, to from a direct-conversion receiver (DCR). The DCR achieves a CG of 26 dB with an NF of 2.7 dB at 21 mW power consumption from a 1 V supply voltage. The port-to-port isolations are better than 50 dB. The IIP <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> and the IIP <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> of the DCR are 33 dBm and -12 dBm, respectively.