Design of the Low Phase Noise Voltage Controlled Oscillator with On-Chip Vs Off-Chip Passive Components

The Voltage Controlled Oscillator (VCO) is one of the most important components for highfrequency transceivers. In this work IBM SiGe 0.5μm technology is used to design an on-chip VCO and MCM-D technology is used to design the VCO with off-chip varactors, inductors and capacitors. Theses results are measured at centre frequency of 2.5GHz and with a voltage supply of 3.3volts. The phase noise of the on-chip VCO is –100.5 dBc/Hz at 100kHz-offset frequency. It also has an output power of 7.6 dBm. The oscillator core consumes 34mA and the output buffer drew 6.23mA. The voltage supply is 3.3 volts. The chip size is 0.5x1.2 mm. The off-chip design has a phase noise of -103.1 dBc/Hz at 100kHz-offset frequency. The on-chip VCO with extracted parasitic has a phase noise of –93.08 dBc/Hz at 100kHz-offset frequency. The tuning range for the on-chip VCO solution is 2.37 to 2.55GHz.