Integrated Microstrip Lines With Co–Ta–Zr Magnetic Films

Abstract

Microstrip transmission lines with ferromagnetic Co-Ta-Zr cores are investigated in this paper. Compared to nonmagnetic devices, an increase in both inductance ( 11) and quality factor ( 6) is achieved in the transmission lines. The role of the magnetic material's electrical resistivity and the effect of the shape-induced anisotropy field (created by patterning the magnetic film into narrow stripes) are discussed. It is shown that the nonuniform distribution of the shape anisotropy inside the Co-Ta-Zr pattern can be used to advantage by proper placement of the signal line, thereby increasing the ferromagnetic resonance (FMR) frequency of the magnetic core. Inductance enhancement is achieved at frequencies up to 10 GHz.Index Terms-Magnetic anisotropy, magnetic microwave devices, microstrip, planar transmission lines, soft magnetic films.

Effect of Dopants on the Microwave Magnetic Characteristics of FeCoBM-Al₂O₃ Soft Magnetic Thin Films

“…To improve the most important characteristics (f r ,µ, eddy current loss) of the soft magnetic films , many works have been reported. Magnetic metal-insulator granular films (MIGF) such as FeCoB-N x O y (NxOy =SiO 2 ,Al 2 O 3 ,etc) show both good soft magnetic properties and high ρ, as their unique microstructure with dielectric amorphous phase were random embedded in nano-sized ferromagnetic particles [8][9][10][11].Many transition metal elements ,such as Nb, Zr, Hf, Mo ,Ta, Ti etc, which can tailor the M s , coercive force (H c ), H k and ρ by affecting the microstructure and stress of the soft magnetic films ,have been adopted into soft films [12][13][14][15][16][17][18][19][20][21][22][23].In this paper，We tried to adopt these elements into Fe 40 Co 40 B 20 -Al 2 O 3 films and the soft magnetic and microwave magnetic characteristics of these films were studied. The effects of annealing treatment on the magnetic properties of the films were also reported at the end of this paper.…”