Abstract: A resonator includes a conductive casing provided with a threaded screw hole, a screw at least partially inserted into the casing, and a fixing member fixing the screw and having a threaded screw hole. In the resonator, the linear expansivity of the casing and the linear expansivity of the fixing member, and preferably also that of the screw, are substantially equal.

Abstract: A small dielectric duplexer using a small TM mode dielectric resonator having a low loss is formed. On the transmission side thereof, TM double mode dielectric resonators and a TM triple mode dielectric resonator are arranged in a line so that their opening surfaces face the same direction. On the receiving side thereof, TM single mode dielectric resonators and a TM triple mode dielectric resonator are also arranged in the same direction in a similar manner as the transmission side. The external dimensions of the plurality of these dielectric resonators are made uniform by selecting a dielectric having a dielectric constant according to the degree of multiplexing. The opening surfaces of the cavities are covered by a panel having input/output terminals, an antenna connection terminal and input/output loops and by a panel having coupling loops. In this manner, a small dielectric duplexer with uniform external dimensions and a low loss is formed.

Abstract: Ceramic cavities 1a and 1b have upper and lower open faces and contain dielectric cores 2a and 2b formed integrally therein. The ceramic cavities 1a and 1b are sandwiched between upper and lower panels 3 and 4 at the upper and lower open faces, respectively, of the ceramic cavities 1a and 1b via grounding plates 5a and 5b and grounding plates 6a and 6b, respectively, and the upper and lower panels 3 and 4 are fixed by screws. Based on this structure, a problem of an unreliable joint part between an open face of a ceramic cavity and a metal panel connected directly to each other by soldering and the problem of increase of the number of components of a structure in which a printed circuit board is mounted to the open face of the ceramic cavity by using grounding plates can be overcome, even when the ceramic cavity has an open face formed in a complex shape.

Abstract: A resonator includes a conductive casing provided with a threaded screw hole, a screw at least partially inserted into the casing, and a fixing member fixing the screw and having a threaded screw hole. In the resonator, the linear expansivity of the casing and the linear expansivity of the fixing member, and preferably also that of the screw, are substantially equal.

Abstract: A dual TM-mode dielectric resonator apparatus comprises a dual TM-mode dielectric resonator consisting of two columnar TM-mode dielectric resonators (1) crossed inside a cavity (2); and a partition plate (3) providing a window for electromagnetic field coupling between an external apparatus and the dielectric resonator. The partition (3) is disposed on the side surface of the cavity (2) opposing the external apparatus and constituted by forming a first shield conductor (30a) on a first main plane (S1) of a dielectric sheet (50) and a second shield conductor (30b) on a second main plane (S2). The first shield conductor (30a) includes parallel slits (32) formed in parallel with the longitudinal direction of one of the TM mode dielectric resonators, while the second shield conductor (30b) includes slits (31) formed in a region substantially opposed to the first slits (32). Further, a plurality of such dual TM-mode dielectric resonator apparatus described above are combined to form a band-pass filter.

Abstract: Dielectric resonators 2a, 2b and 2c which compose a transmitting filter are stored in a conductive casing in one line. Dielectric resonators 3a, 3b and 3c which compose a receiving filter are stored in the conductive casing in one line. Earth electrodes of the neighboring dielectric resonators 2a and 3a, 2b and 3b, 2c and 3c are connected in earth by conductive members 11 such as metal foils.