Design and analysis of a novel 90 nm tunable active-inductor with high Q-factor in LC-VCO for C and Ku band

Abstract In this paper, an LC-VCO architecture incorporating a novel tunable active inductor using 90 nm gpdk technology for wireless communication systems is proposed. The active inductor presented here employs a three-stage cascoding strategy, with transistors operating in the subthreshold region. The proposed topology of the active inductor is then implemented in LC-VCO architecture in place of conventional resonant circuits to increase the tuning range. The simulation results of active inductor exhibit a high Q-factor of 3040 at 8.1 GHz and a low inductance of 2.26 nH. The LC-VCO generates a frequency range of 4.636 GHz to 12.34 GHz at supply voltage 1.1 V, making the design viable for sustainable operations within the C-band and Ku-band frequencies. Phase noise of −75.742 dBc Hz −1 at 1 MHz and a figure of merit of −170.54 @8.64 GHz were achieved, with enhanced power consumption ranging between 24.16 mW and 27.28 mW. The proposed LC-VCO occupies a compact area of (29.5 μm × 29.5 μm). The outcomes illustrate that the newly proposed active inductor based LC-VCO operates more efficiently than the existing LC-VCOs.