Chapter 12 ferromagnetic RF integrated devices-RF integrated noise suppressor and integrated inductors

We demonstrated the RF integrated noise suppressor and thin-film inductor using ferromagnetic film. The transmission parameter (S ₂₁) of the integrated noise suppressor was compared with that of the nonintegrated noise suppressor. The magnitude of signal attenuation at the resonance point was greatly increased by the integration up to -30 and -57 dB for the 1-μm-thick and 2-μm-thick CoNbZr films, respectively. The closed magnetic circuit type GHz-drive integrated spiral inductors were fabricated with a four-turn and 380 × 380 μm² two-port-type inductor with ground guards, which consisted of a sandwich 2-μm-thick Cu coil in between a patterned 1-μm-thick CoNbZr film. The 10/3 (line/space [μm]) designs with 2-μm-thick SiO₂ insulating layers exhibited a quality factor Q = 14.7, being highest among the published data at 1 GHz.