Title :
Sandwich-type ferromagnetic RF integrated inductor
Author :
Yamaguchi, Masahiro ; Baba, Makoto ; Arai, Ken-Ichi
Author_Institution :
Res. Inst. of Electr. Commun., Tohoku Univ., Sendai, Japan
fDate :
12/1/2001 12:00:00 AM
Abstract :
The first demonstration of a sandwich-type ferromagnetic RF integrated spiral inductor for the 2-GHz range is reported. Two ferromagnetic CoNbZr films were set to sandwich the spiral in order to enhance the amount of magnetic flux linkage across the coil current. The stresses given from the insulator to the ferromagnetic film were studied. The inductance L of 7.9 nH and the qualify factor Q of 12.7 were obtained for a 200 μm×400 μm size four-turn rectangular spiral at f=2 GHz. The inductance was better than that of an air core of the same coil size by 19%, and the Q was better by 23%. Comparison with the on-top magnetic film type was also discussed
Keywords :
Q-factor; amorphous magnetic materials; cobalt alloys; coercive force; coils; ferroelectric materials; inductors; magnetic flux; magnetic hysteresis; magnetic permeability; magnetic susceptibility; magnetic thin film devices; niobium alloys; soft magnetic materials; zirconium alloys; 2 GHz; CoNbZr; amorphous films; coercive force; coil current; ferromagnetic RF integrated inductor; ferromagnetic films; four-turn rectangular spiral; high-frequency characteristics; inductance; magnetic flux linkage; magnetic permeability; qualify factor; sandwich-type spiral inductor; square hysteresis loop; Coils; Couplings; Inductance; Inductors; Insulation; Magnetic films; Magnetic flux; Radio frequency; Spirals; Stress;
Journal_Title :
Microwave Theory and Techniques, IEEE Transactions on
