A CMOS subharmonic mixer with input and output active baluns

A CMOS 0.18 μm subharmonic mixer is experimentally demonstrated that uses active baluns at the local oscillator (LO) and RF inputs, as well as at the output. With this subharmonic mixer, a 2.1 GHz RF input and a 1.0 GHz LO input produce a 100 MHz output signal. The conversion gain is 8 dB, the LO and RF input reflection coefficients are better than −10 dB, and IIP3 is −8.5 dBm.