A 4.6-mW 45-GHz compact-size darlington-pair LC-VCO in 0.18-μm cmos technology

This work proposes a 45-GHz Darlington-pair voltage-controlled oscillator (VCO) in 0.18-μm CMOS process. The Darlington-pair transistors achieve a 10.3-GHz higher unit gain cutoff frequency (f_T) and lower negative resistance than those obtained in single MOS counterpart. This feature lowers the minimum current to start oscillation and hence reduces the power consumption in millimeter-wave frequency regime. Meanwhile, a high-Q straight transmission line is used to replace the inductor of the VCO resonator and achieves a good phase noise of -106.3 dBc/Hz at 10 MHz offset. The achieved figure-of-merit is -172.7 dBc/Hz while consumes a low direct current (DC) power consumption of 4.6 mW from a 1.5 V supply. The chip size including all pads is 0.19 mm².