Nonreciprocal circuit device with a casing average surface roughness less than or equal to 0.9 microns

Abstract

An isolator serving as a nonreciprocal circuit device includes a permanent magnet, a ferrite to which a DC magnetic field is applied by the permanent magnet, a plurality of center electrodes placed on the ferrite, and upper and lower casings for accommodating the permanent magnet, the ferrite, and the center electrodes. The upper and lower casings are made of a material chiefly containing iron, and the average value of the surface roughness of the casings is less than or equal to 0.9 μm. The front and rear surfaces of the upper and lower casings are Ag-plated.

Dependencies are inferred from the claim text.