A Frequency Synthesizer Using Low Voltage Active Inductor VCO with a Feedback Resistor

摘要

This paper presents a frequency synthesizer using low voltage active inductor VCO (Voltage Controlled Oscillator). The low voltage active inductor VCO with feedback resistor increases the quality-factor(Q) and its equivalent inductance. Under certain conditions, the low voltage active inductor with feedback resistor generates a negative resistance at the input. In this paper, the conditions for negative resistance are obtained by small signal analysis. The designed low voltage active inductor VCO has a measured tuning range from 1059MHz to 1223MHz. The measured phase noise at 1.178GHz is -81.8dBc/Hz at 1MHz offset.