Dielectric filter, dielectric duplexer, mounting structure thereof, and communication device

A communication device comprising:

• a dielectric block including a first surface and a second surface opposite to each other;
• a resonator hole extending between the first surface and the second surface of the dielectric block, said resonator hole including a large-sectional area portion, a small-sectional area portion and a step portion between the large-sectional area portion and the small-sectional area portion;
• an inner conductor provided on the inner surface of the resonator hole;
• an outer conductor provided on the outer surface of the dielectric block, whereby said resonator hole in said dielectric block provides a dielectric filter;
• the inner conductor being electrically left unconnected to the outer conductor at the first surface of the dielectric block so as to provide an open-circuited surface of said dielectric block, and being electrically connected to the outer conductor at the second surface of the dielectric block so as to provide a short-circuited surface of said dielectric block;
• and
• a seat portion provided on at least one of a comer and an edge of the first surface of the dielectric block, wherein said seat portion serves as a mounting surface of the dielectric block, and wherein said seat portion defines a gap between said open-circuited surface and said mounting surface.