Soft magnetic materials application in the RF range

Recent rapid progress of information technologies has enlarged the application fields of soft magnetic materials operating in GHz range. Firstly, this paper reviews the recent achievement of magnetic thin films applied in high-frequency devices. Then, a newly developed permeability measurement technique is introduced, and then ferromagnetic RF integrated inductors and noise suppressors are discussed from an application viewpoint. In particular, the influences of alignment between the patterned magnetic films and coil legs on the characteristics of inductors are manifested. As a result, a quality factor of 13 in a "shift type" inductor at 1.2 GHz was achieved.