Magnetic-particle-composite-medium-filled stacked-spiral inductors for rf complementary metal oxide semiconductor (CMOS) applications in GHz are demonstrated.The new inductor features a nearly closed magnetic circuit loop,an optimized high-permeability and low-loss sub-1 μm magnetic particles composite core,and a developed 0.18-μm CMOS-compatible device fabrication process.An equivalent circuit model with structural amplifying factors is proposed and modeled.The prototype of the 6-level stacked inductor with Co2Z magneticparticles-composite-medium filling increases the inductance L by 50％,and quality factor Q by 37％ at frequencies as high as 1 GHz,with high inductance density as 825 nH/mm2 and a reduced size area by 80％ compared to the planar spiral inductor.