Designing an ultra low phase noise 4.5 GHz VCO using multiple coupled resonators and MOS devices

摘要

This paper shows a 4.5 GHz center frequency push-pull oscillator based on the use of NMOS and PMOS transistors, the use of multiple-coupled resonators as tuned elements, and source RF feedback for improved phase noise. Two MOS transistors are used as varactors. At 5 GHz and 1 MHz offset, the phase noise is -118 dBc/Hz. This paper gives detailed insight into the design procedure of the oscillator, including the device selection.