A Fully Differential Active Inductor with Cascode Current Mirror Using 0.18-um Technology for RF Frequency

Abstract

This paper introduces a fully differential CMOS active inductor integrated with a cascoded current mirror, tailored for applications within the RF frequency range. The active inductor design is meticulously realized using CMOS 0.18-µm technology. The circuit implementation comprises a fully differential cross-coupled pair of transistors, strategically employed to impart negative feedback, thereby enhancing the quality factor (Q). The cascoded current mirror functions as a pivotal biasing component, facilitating control over the current source to modulate negative feedback and Q factor tuning. Simultaneously, two resistors integrated into the differential structure are crucial in managing the frequency spectrum. Simulation results substantiate a Q factor of 16k, coupled with an inductance of 14 nH, prominently achieved at 3 GHz frequency.  Additionally, the objective of achieving a robust Q factor at 3.5 GHz, amounting to 500, is successfully realized. Noteworthy is the adaptability in achieving a frequency range spanning 2 GHz to 3.6 GHz by manipulating resistor values. Furthermore, the study observes that manipulation of supply voltage and current source enables the tuning of Q factor values from 70 to 16k. A performance assessment, juxtaposed with previously published works, underscores the viability of the proposed active inductor for applications within the gigahertz frequency range of RF.