A novel methodology for the design of LC tank VCO with low phase noise

— A novel methodology for reducing the phase noise of cross-coupled LC tank VCO is presented, verified and measured. The fundamental relationship between the phase noise and the channel length of the cross-coupled MOS transistors is derived, and an optimum channel length of MOS transistors is pointed for cross-coupled LC tank VCO with the lowest phase noise. A 2 GHz LC tank VCO is designed by this methodology fabricated by 0.18 µm CMOS technology. The phase noise is 103.3 dBc/Hz at 100 kHz offset frequency and -118.9 dBc/Hz at 600 kHz offset with low-power consumption around 3.15 mW. The best FOM value of 186 is achieved compared to the reported 2 GHz VCO. The tuning rang is 14% at a center frequency of 2.05 GHz.

• Type: Conference
• Year: 2005
• Where: ISCAS
• Authors: Lin Jia, Jianguo Ma, Kiat Seng Yeo, Manh Anh Do
• Keywords: Cross-coupled Lc Tank, ISCAS 2005, Lc Tank Vco, Phase Noise