A CMOS 3.5GHz current draining mixer

Abstract

The drive for cost reduction has led to the use of CMOS technology for highly integrated radios. This paper presents a new CMOS active mixer topology with current draining features, to reduce flicker noise effect. Mixing is achieved by exploiting two transconductors with cross coupled outputs, which are alternatingly activated by the current commutating CMOS switches. Realized in 0.18μm CMOS technology, compliant with IEEE 802.11a application and operating from 1.8V power supply, the design consumes 4mW of power. The mixer exhibits a third order input intercept point (IIP3) of better than 31dBm. An overall noise figure of 27.8dB is achieved at 100kHz. The mixer also shows an input dynamic range performance of 24.18dBm, with –174.7dB carrier feedthrough suppression.