Millimeter wave hexagonal nano-ferrite circulator on silicon CMOS substrate

Hexagonal ferrites such as BaFe
₁₂
O
₁₉
have very strong uniaxial anisotropic magnetic field and remanent magnetism. By employing these properties, magnetic devices can work in the tens of GHz frequency range without strong external magnetic field. The micro- and nano-sized hexagonal ferrite can be conveniently utilized to fabricate magnetic components integrated in CMOS integrated circuits. A circulator working at 60 GHz is designed and integrated into the commercial CMOS process.