A 3.1∼4.8 GHz wideband mixer for MB-OFDM UWB receivers with improved noise performance

A CMOS down-conversion mixer for MB-OFDM (Multi-Band Orthogonal Frequency Division Multiplexing) UWB (Ultra-Wide Band) application is presented. The mixer is implemented with a double-balanced Gilbert-cell architecture and adopts dynamic current source to improve noise performance. Two inductors are also introduced to reduce the flicker noise. Designed in SMIC 0.18 ¿m CMOS process, simulation results show a conversion gain of 9 to 11.5 dB, a noise figure of 10.8 to 13.2 dB, and an input-referred third-order intercept point of -10.5 to -8.2 dBm. The power consumption of the mixer core is 11.3 mW.