A fully integrated sub-1 V 4 GHz CMOS VCO, and a 10.5 GHz oscillator

This paper presents the design and experimental measurements of three CMOS LC-based oscillators. The first circuit is optimized for low voltage operation in a 0.25 µm process, requiring only a 0.85 Volt power supply and reaching a maximum frequency of 4 GHz. The second circuit is a 5 GHz oscillator in a 0.35 µm process operating from a 1.5 Volt power supply and optimized for a wide tuning range (10%) while maintaining reasonable phase noise (-87.3 dBc/Hz @ 100 KHz offset). Finally, the third oscillator targeted high frequency operation reaching a maximum oscillating frequency of 10.5 GHz in a 0.35 µm process. The oscillators make use of on-chip components only, allowing for simple and robust integration.