Abstract: A dielectric resonance device includes a cavity body, a support base disposed inside the cavity body, and a dielectric core supported by the support base. A stepped portion is provided inside the cavity body such that a gap between the outer circumferential surface of the dielectric core and the inner wall surface of the cavity body and a gap between the peripheral portion of the support-base attachment surface of the dielectric core and the stepped portion change in opposite directions with temperature variation. Thus, variation with temperature in the resonance frequency of a TM01&dgr; mode is suppressed.

Abstract: A filter includes a dielectric resonator, a cavity for holding the dielectric resonator therein, an external connector mounted on the cavity, and a coupling loop connected to the external connector so as to electromagnetically couple with the dielectric resonator. The coupling loop is formed by bending a metal plate nearly into the shape of an L, and is provided with a rib extending in a direction that is not parallel to the bending line.

Abstract: A long-life highly reliable dielectric resonator, a dielectric filter using the dielectric resonator and a dielectric duplexer, in which the heat accumulated in concave portions is dissipated. The dielectric resonator comprises a frame, a column-shaped dielectric resonant element disposed so as to be integral with the frame at ends thereof, the concave portions formed from the external surface of the frame into the dielectric resonant element in the direction of the axis of the dielectric resonant element, a conductor formed on the overall outer surface of the frame including inside the concave portions, and thermal-conducting means inserted in the concave portions.