Non-reciprocal circuit device having small absolute value of temperature coefficient of out-of-band attenuation and small absolute value of temperature coefficient of maximum- isolation frequency

摘要

A non-reciprocal circuit device includes a magnetic disk; a plurality of central conductors intersecting each other on a surface of the magnetic disk; a plurality of matching capacitors connected to the respective central conductors; and an SmCO-based or AlNiCo-based magnet that is stacked on the magnetic disk, the SmCO-based or AlNiCo-based magnet applying a bias magnetic field to the magnetic disk. The magnetic disk is composed of garnet ferrite represented by any one of the following Formulae (1) to (3): Y_3-xGd_xFe_t-2y-zCo_ySi_yAl_zO₁₂  (1) Y_3-x-uGd_xCa_uFe_t-2y-u-zCo_ySi_yD_uAl_zO₁₂  (2) Y_3-xGd_xFe_t-2y-v-zCo_ySi_yIn_vAl_zO₁₂  (3)