An 0.04-10.32 nH Ultracompact Tunable Inductor Based on Flexible Magnetic Coupling Tuning Technique

• Published in: IEEE transactions on electron devices 2024-08, Vol.71 (8), p.4945-4951
• Main Authors: Zheng, Yanwen, Shan, Guangbao, Fan, Xiang, Yang, Zifeng, Li, Guoliang
• Format: Article
• Language: English
• Subjects: Cost analysis; Coupling circuits; Couplings; Inductance; Inductor; Inductors; Insulation; Integrated circuit modeling; magnetic coupling; Man-machine interfaces; reconfigurable; Reconfiguration; Transceivers; tunable; Tuning; Wearable technology
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/TED.2024.3418298

The miniaturized and low-cost reconfigurable transceivers show promising prospects in brain-machine interfaces, implantable devices, and wearable devices. As basic elements of transceivers, further improvement of tuning range, operating frequency, and area of tunable inductors are extremely needed. In this work, a magnetic coupling ultrawide range inductors tuning technique is proposed and analyzed with the process-based coupling circuit model. The model simulation and test chip verification results are in good agreement. From dc to 30 GHz, an inductance value of 0.04-10.32 nH (self-inductance is 1.03 nH), a tuning range of 99.61%, and a quality factor (Q) of 145.6 are achieved. This indicates that a 10.02-fold increase in inductance value can be obtained without increasing the chip area compared to a fixed inductor with an area of 95 \times 130 \, \mu m. The tuning technique and model can be employed for the design of tunable matching networks and filters to further improve the integration of reconfigurable radio frequency (RF) transceivers.