Abstract: A highly compact inductor formed on opposite faces of a dielectric substrate. Sets of parallel spaced conductive traces formed on the opposite faces of the substrate are interconnected by metallized vias through the substrate, in such a way as to form a continuous spiral conductive path. The inductor is preferably formed as two closely adjacent segments, each with conductive traces on each face of the substrate and each having metallized vias interconnecting the conductive traces. The segments are electrically connected in series and produce a magnetic field that extends through each segment in opposite directions and is closely coupled from one segment to the other. The inductor is, therefore, electromagnetically similar to a wire-wound toroidal inductor, providing high inductance and contourable Q values, but is highly compact, especially in the z-axis direction normal to the substrate.