Design and analysis of two K-band CMOS VCOs for next generation wireless systems

In this paper, two wideband K-band LC-tank VCOs for next generation wireless communication applications are designed, fabricated, and verified in a 0.13-μm CMOS process. A thorough comparison study of 12% tuning-range SS-VCO and 9.49% DS-VCO is conducted based on the measurement results and calculations of figure-of-merits (FoM) and FoM_T. The measured phase noise of SS-VCO at 22.29 GHz carrier frequency is -101.77 dBc/Hz at 1MHz frequency offset, compared to -100.51 dBc/Hz of its DS-VCO counterpart at 26.08 GHz oscillation frequency. Under 1-V power supply, the SS-VCO only consumes 7 mA, and its FOM_T achieves -181.8 dBc/Hz, which outperforms the DS-VCO by more than 5 dB.