A Low-Power Reconfigurable Mixer for MB-OFDM UWB Receivers

摘要

This paper presents a low-power down-conversion mixer for 3.1～4.8GHz 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 0.13μm CMOS process, post-simulation results show a conversion gain of 8.2 to 9.7dB, a single-sideband noise figure of 10.4 to 12.4dB, and an input third-order intercept point of-3.2 to -1.2dBm over 3.1～4.8GHz band. The mixer core dissipates 3.7mW under 1.2V supply, and the total area of the layout is 0.81×0.5mm~2. Based on the proposed topology, an overall 3.1～10.6GHz MB-OFDM UWB mixer can be designed with barely any more power consumption and circuit complexity.