Premium
Thin‐film permanent magnet requirements for magnetic devices in MMIC
Author(s) -
Stancil Daniel D.
Publication year - 1989
Publication title -
microwave and optical technology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.304
H-Index - 76
eISSN - 1098-2760
pISSN - 0895-2477
DOI - 10.1002/mop.4650020302
Subject(s) - materials science , yttrium iron garnet , circulator , magnetization , microstrip , biasing , ferrite (magnet) , stripline , magnet , ferromagnetic resonance , coercivity , microwave , optoelectronics , monolithic microwave integrated circuit , condensed matter physics , electrical engineering , magnetic field , voltage , engineering , physics , telecommunications , composite material , amplifier , cmos , quantum mechanics
The use of sputtered thin‐film permanent magnets for biasing microwave devices in planar geometries compatible with monolithic integration is considered. Possible geometries are presented for biasing a reciprocal microstrip phaser at 7 GHz, a stripline circulator at 15 GHz, and a magnetostatic wave delay line at 3 GHz. Yttrium iron garnet (YIG) is assumed to be the ferrite used in each of these devices. It is concluded that the in‐plane magnetization orientation is more useful than normal magnetization, and thick films (100‐150 μm) are needed with high magnetization ( > 16 kG) and moderate coercivity ( > 2 kOe). Below‐resonance devices are preferable because of their modest field requirements and tolerance to bias field inhomogeneities.