An mm-Wave CMOS I-Q Subharmonic Resistive Mixer for Wideband Zero-IF Receivers

In this letter, we propose a novel wideband subharmonically pumped fully differential I-Q resistive mixer architecture, which eliminates the necessity for on-chip dc-blocking capacitors to integrate IF amplifiers. The proposed differential subharmonic mixer topology is verified by presenting a CMOS millimeter-wave monolithic integrated circuit (MMIC), which includes the mixer and two on-chip differential IF amplifiers at the mixer's I- and Q-channels. The 3-dB IF frequency bandwidth is measured from 0.01 to 5 GHz with a peak conversion gain (CG) of -2 dB and an image rejection ratio (IRR) of more than 25 dB over the IF frequency range. The proposed mixer covers the input signal (RF) frequency from 170 to 185 GHz. The mixer has also been tested with an on-chip voltage-controlled oscillator (VCO) and shows -4.7-dB CG with a 3-dB IF bandwidth from 0.01 to 4.5 GHz.