A reconfigurable 0.7–2.6GHz wideband mixer for multi-mode multi-standard receivers in 0.18μm RF CMOS

A reconfigurable mixer for direct conversion multi-mode multi-standard receivers is presented. Different from traditional current-commutating passive mixers, transconductor stage in this design is variable, and the transimpedance amplifiers (TIA) stage is a second-order TIA based on Tow-Thomas biquad topology, working as a current mode filter with tunable bandwidth. From 700MHz to 2.6 GHz, it provides four voltage conversion gains (8/14/20/26dB) and three -3dB intermediate frequency (IF) bandwidth (5/7.5/10MHz). Under the maximum gain, its noise figure NF is 9.1dB; and under the minimum gain, its IIP3 is about 8.5dBm. It drains a current of 4.9/7.8mA from a 1.8V voltage supply at different gain mode, respectively.