CMOS based compact wide band tunable active inductor design

This paper presents a compendious architecture of an active tunable inductor with precise and wide tunability over its inductance value. Proposed tunable inductor requires only 3Ts (three transistors) to implement the design which reduces the transistor count as compared to 5Ts and 10Ts designs already available in literature. Broader range (35 GHz to 46 GHz) of linear operation with high quality factor (Q) is also obtained from the design presented. The achieved magnitude of impedance ranges from 2.6 KΩ to 6.1 KΩ for frequency variation of 25 GHz to 60 GHz. Further, maximum quality factor is obtained for input current of 62.3 μA. Apart from these, the proposed active inductor circuit is suited for high frequency operations up to 50 GHz. Further, this paper also compares the proposed inductor design with the designs already reported. The simulation results have been extensively verified using Virtuoso Analog Design Environment of Cadence Design System @ 45-nm technology node.