Application of negative capacitance circuit to extend variable frequency range of on-chip VCO

摘要

In recent years, there is an increasing demand for monolithic VCO with a wide frequency range for use with high data rate mobile transceivers, etc. Conventional on-chip LC oscillators using varactors suffer from narrow tuning range, due to limited variable capacitance range of on-chip varactors. This paper presents a technique for extending the variable frequency range of on-chip VCO, by using negative capacitance circuit to cancel out the varactor's fixed capacitance.