Design and Characterization of Inductors for Self-Powered IoT Edge Devices

This paper discusses the design, fabrication, and characterization of packaged planar inductors with magnetic material [nickel zinc (NiZn) ferrite]. Inductors are designed specifically for Internet of Things (IoT) applications based on power loss in an IoT architecture. Different spiral inductor geometries are demonstrated on a printed wiring board with varying thicknesses using a stencil printing process. The magnetic material can be applied to one or both sides of the inductor and, therefore, provides size reduction. This paper examines the role of varying dimensions on inductor performance along with model-to-hardware correlation. The fabrication process demonstrates inductance increase through a very simple procedure for applying a magnetic material on both sides of the inductor, while having flexibility to customize the geometry for minimal power loss in an IoT architecture. With NiZn ferrite material added to both sides of the inductor, the inductance increases between approximately 60% and 80% for the two substrate thicknesses studied, as compared to air-core inductors.