136 / 2019-06-11 16:09:11

A novel active inductor with high self-resonance frequency high Q factor and independent adjustment of inductance

active inductor; high-frequency; independent adjustment

Based on gyrator-C principle, a novel active inductor with high self-resonance frequency, high Q factor and independent adjustment of inductance is proposed in this paper. A varactor is added in parallel with the positive transconductor to improve the tunable range of inductance. A tunable resistor between positive transconductor and negative transconductor is used to generate negative resistance, thus enhance the Q factor. Furthermore, a feedback capacitor is also employed not only to generate negative conductance for enhancing the Q factor, but also to provide negative capacitance for achieving high self-resonance frequency. The results show that the self-resonance frequency is up to 12GHz, the peak Q factor is more than 1300. The peak inductance can be adjusted significantly between 25.1nH-84.8nH with the tuning range of 108.6%, whereas the variation of the peak Q factor is only 1.6%.