Multilayer stacked coreless printed spiral winding inductor with wide frequency bandwidth

In this paper, three types of winding methods for the multi-layer stacked coreless printed spiral winding inductors are studied and evaluated for megahertz operation. They are traditional winding, alternating winding and partial alternating winding. The winding parasitic capacitances of different windings structures are estimated by distributed capacitance models. The electric field energy distributions in the inductors are derived from the voltage profiles to illustrate the relative magnitudes of winding parasitic capacitances. Calculated results show that partial alternating winding has a wide frequency bandwidth with reduced number of through-hole via. All calculated parameters are confirmed with measurements. The results provide useful information for the optimal design of coreless spiral or core-based planar inductors.