Design and Fabrication of Toroidal Inductors for Mixed Signal Packaging

Abstract

The demand for efficient, lightweight consumer products created the need for miniaturization of passive components especially inductors which are some of the bulkiest parts of an integrated system. The purpose of the work described here was to study toroidal inductor structures since they were compact and self-shielding. Toroidal inductors were modeled using a commercial electromagnetic simulator. The results show that these structures have good characteristics in terms of inductance, quality factor and area. Three different structures are fabricated and experimentally characterized using the HP Vector Network Analyzer. We also make several observations about the effect of the placement of each pair of top and bottom metal strips with respect to each other on the flux linkage and hence, the inductance and quality factor of the inductor.