The stray capacitance of a ferromagnetic RF integrated inductor is discussed on the basis of both experiments and equivalent circuit analysis. The test inductor occupied an area of 380 x 380 μm2, and has an inductance of 7.5nH at 1 GHz. The coil-magnetic film capacitance was most significant, reducing the LC resonance frequency from 6 GHz to 5 GHz. This became lower with increasing the distance between the coil and magnetic film, while the inductance was almost constant.
