Title :
Passive coplanar isolator with barium ferrite thin films
Author :
Capraro, S. ; Rouiller, T. ; Le Berre, M. ; Chatelon, J.P. ; Joisten, H. ; Bayard, B. ; Barbier, D. ; Rousseau, J.J.
Author_Institution :
DIOM, Saint-Etienne Univ., France
Abstract :
The development of integrated devices combining a ferrite is a major focus of current research. Barium hexaferrite (BaFe12O19 or BaM), which exhibits a high anisotropy field and high coercive force are deposited on alumina substrate using an RF sputtering system. After deposition BaM films are amorphous and a post deposition thermal annealing is needed to obtain magnetic properties. The saturation magnetization and coercive force was about 500 mT and 330 kA/m. After that, coplanar lines were made with BaM thin films on alumina substrates and with gold conductor. The transmission coefficients of a barium ferrite coplanar isolator are measured up to 55 GHz. The measurements of transmission parameters S12 and S21 was performed by a 65 GHz vector network analyzer and a probing system. First experimental results showed an isolation of 3.3 dB/cm at 50 GHz.
Keywords :
annealing; barium; barium compounds; coercive force; ferrite isolators; ferrites; magnetic anisotropy; magnetic thin films; sputtering; substrates; 50 GHz; 65 GHz; BaFe12O19; RF sputtering system; alumina substrate; barium ferrite coplanar isolator; barium ferrite thin films; gold conductor; high anisotropy field; high coercive force; integrated devices; passive coplanar isolator; post deposition thermal annealing; saturation magnetization; Amorphous materials; Anisotropic magnetoresistance; Annealing; Barium; Coercive force; Ferrite films; Isolators; Magnetic films; Radio frequency; Sputtering; Barium ferrite; microwave; passive isolator;
Conference_Titel :
Industrial Electronics, 2004 IEEE International Symposium on
Print_ISBN :
0-7803-8304-4
DOI :
10.1109/ISIE.2004.1571774