To provide a compact dielectric filter, having improved characteristics by adopting filter structure for miniaturization without changing the volume of a dielectric, especially for reducing the occupancy area of a substrate, even though it has not been sufficient to cope with the needs for miniaturizing a radio equipment terminal, since wavelength in a waveguide becomes smaller, in proportion to the square of the dielectric constant of the dielectric in the waveguide filter.
This dielectric filter 1 has a dielectric substrate 4, where at least two dielectric plates 2 and 3, are laminated for integration. Island-like I/O electrodes 7 and 8 are formed in contact with the side of a pair of main surfaces of the dielectric substrate 4, and an internal ground electrode 5 having an opening 6 for coupling is provided on the lamination interface of the dielectric plate 4. Additionally, ground conductors 9, 10, and 13 are formed on a pair of main and side surfaces of the dielectric substrate 4, so that the earth conductors are separated and insulated form the I/O electrodes 7 and 8, and at the same time, are equipped with conductor exposure sections 11 and 12 in a specific shape that include the I/O electrodes 7 and 8.
MURASE EITOKU
KURIHARA KAZUYA
