A low-power reconfigurable mixer for MB-OFDM UWB receivers

This paper presents a low-power down-conversion mixer for 3.1~4.8 GHz MB-OFDM UWB applications. The proposed mixer is based on folded double-balanced Gilbert cell and employs following techniques: two cross-coupling capacitors at the transconductance stage enhance conversion gain and reduce input noise; two choke inductors reduce flicker noise from the switch quad; tuning capacitors and resistors are added to fit different UWB bands. Designed in SMIC 0.13 ¿m CMOS process, post-simulation results show a conversion gain of 8.2 to 9.7 dB, a single-sideband noise figure of 10.4 to 12.4 dB, and an input third-order intercept point of -3.2 to -1.2 dBm over 3.1~4.8 GHz band. The mixer core dissipates 3.7 mW under 1.2 V supply, and the total area of the layout is 0.81 × 0.5 mm². Based on the proposed topology, an overall 3.1~10.6 GHz MB-OFDM UWB mixer can be designed with barely any more power consumption and circuit complexity.