A new approach to RF thin film microinductors

A new approach to RF thin film inductors has been investigated. A toroid inductor design was realized in thin film technology. An operating frequency in the range from 100MHz to 3 GHz was targeted. Softmagnetic FeCoBSi was used as cure material. The magnetic film were sputter deposited in a multilayer way to realize a crossed magnetic anisotropy in the core. High frequency measurements illustrate the advantages of the unique magnetic geometry. The influence and benefits of such a magnetic core on microinductors will he discused in detail. The results show, that such crossed anisotropy microinductors are very promising alternative to common planar spiral inductors in the RF range.