Patent ID: 7567152

Claim:
A passive part comprising, in a dielectric substrate, a filter, an unbalanced to balanced converter, and a connector electrically interconnecting the filter and the unbalanced to balanced converter, wherein said filter is disposed in an upper portion of said dielectric substrate and said unbalanced to balanced converter is disposed in a lower portion of said dielectric substrate, or said filter is disposed in the lower portion of said dielectric substrate and said unbalanced to balanced converter is disposed in the upper portion of said dielectric substrate; a first ground electrode is disposed on a surface of said dielectric substrate close to said filter, and a second ground electrode is disposed on a surface of said dielectric substrate close to said unbalanced to balanced converter; an innerlayer ground electrode is disposed between said filter and said unbalanced to balanced converter; said filter has at least one resonator; said resonator has a via hole having one end connected to said first ground electrode, and an electrode connected to the other end of said via hole and positioned across a dielectric material from said innerlayer ground electrode; said via hole comprises a resonant electrode; a portion, which faces said innerlayer ground electrode of said electrode, serves as an open end of said resonator; and a portion of said via hole, which is connected to said first ground electrode, serves as a short-circuited end of said resonator.