A 60 GHz wide tuning range CMOS self-oscillating mixer using a push-push VCO technique

A wide tuning self-oscillating mixer (SOM) operating from 56 to 64 GHz, using 90nm CMOS technology, is proposed in this work. The entire circuit of a voltage control oscillator (VCO) core, a mixer core and couple line marchand balun. The balanced mixer is symmetric, inherently broad band, and need an LO balun combined with the parasitic capacitances from the mixer. The VCO are used in a 60-GHz push-pull circuit to generate the second harmonic, and a 30-GHz dielectric resonator was used to stabilize the fundamental oscillation frequency. The LC-tank oscillator also functions as a single-balanced LO load to the mixer core. A theoretical expression is given for the conversion gain of the SOM taking into account the time-varying nature of the LO load impedance. Measurements show that the SOM has a conversion gain of 3.4 dB. Its output P_1dB is -12.4 dBm. The chip consumes 17.9 mW of dc power and it occupies an area of 0.64 mm² without pads.