Design of a low power current-driven passive mixer

A 2.2mW splitting low noise trans-conductance amplifier (split-LNTA) current-driven passive mixer for the ultra-high frequency (UHF) radio frequency identifycation (RFID) active tag is presented in this paper. The split-LNTA can alleviate the issues in the conventional current-driven passive mixer utilizing 50% duty cycle local oscillator (LO). So 50% duty cycle LO can be used instead of 25% duty cycle LO to save power and chip area. The extra voltage gain of the matching network in front of the mixer can suppress the noise of the following circuits, which can reduce the power consumption of the LNTA. The mixer was fabricated in SMIC 130-nm CMOS technology. It exhibits 32-dB voltage conversion gain, 7.7-dB DSB noise figure (NF) and −9.1-dBm in-band input-referred third-order intercept point (IIP3). The area of the die is 0.32mm2 and its power consumption is 2.2mW.