Low power, tunable active inductor and its applications to monolithic VCO and BPF

A novel tunable active inductor for low power operation is presented. The DC power consumption of the proposed scheme is about 1/3 of conventional one with wider range of tunability and higher Q. The new bias scheme using the parallel and the series bias resistors reduces the number of bias pins and stabilizes the bias, effectively. This novel low power tunable active inductor is applied to wideband (35% tuning ratio) monolithic VCO and wide tunable (14% tuning ratio) monolithic BPF.