A CLASS AB MONOLITHIC MIXER FOR 900-MHZ APPLICATIONS

A Class AB downconversion mixer for 900-MHz applications is presented. The circuit is implemented in a 25-GHz f(T) bipolar process and consu mes 10.2 mA total current from a 3-V supply. The design has a power ga in of 7.5 dB and operates with supply voltages from 2.7 to 5 V. A sing le-sideband noise figure of 7.5 dB is achieved by design simplicity, u se of bond-wire degeneration in the common-emitter driver stage, and o ptimization of the device sizes and bias currents. An input 1-dB compr ession point of -1.5 dBm is achieved by exploiting the class AB behavi or of the common-emitter driver stage.