Si-based electromagnetic noise suppressors integrated with a magnetic thin film

Electromagnetic noise suppressors on Cu transmission lines and oxidized Si substrate integrated with a SiO2 dielectric and a Co–Fe–Al–O magnetic layer are presented. Extremely large signal attenuation is achieved (−90dB at 20GHz) while the signal reflection is relatively small, being below −10dB. These characteristics are attributed to the distributed capacitance (C) formed by the Cu and the oxidized Si substrate and the Cu∕SiO2∕Co–Fe–Al–O and the distributed inductance (L) due to the magnetic thin film. The main loss mechanism is the L-C resonance and this emphasizes the role of the magnetic thin film providing the inductance.