Ube Industries, Inc.

Shotaro Hayashi

Ryozo Kitoh

Yoshiaki Fujiyama

Takaki Ono

Atsunori Takasugi

A dielectric filter having a plurality of .lambda./4 coaxial dielectric resonators in stages, the resonator being filled with a dielectric material between its inner and outer conductors, comprising at least one stage in which the outer conductor of the .lambda./4 coaxial dielectric resonator is grounded via a capacitance or inductance. The dielectric filter is embodied as a low-pass filter, high-pass filter or a band-pass filter. As a result, by utilizing dielectric resonators having a desired resonant frequency, it is possible to readily achieve a dielectric filter having an attenuating pole in the neighborhood of the frequency passband and small in insertion loss.

Dielectric filter using quarter wavelength coaxial dielectric resonators

A plurality of coaxial type dielectric resonators 1A, 1B each having a dielectric 5 filled between an inner conductor 4 and an outer conductor 3 a dielectric block 2 for capacitor coupling between resonators and between the resonators and input/output terminals. The dielectric block has holes 6A, 6B opposed to the inner conductors 4 of the dielectric resonators, with electrodes 7A and 7B being formed on the inner surfaces of the holes. The electrodes 7A and 7B of the coupling dielectric block and the inner conductors 4 of the resonators associated therewith are connected through electroconductive spacers 9. Further, an input terminal electrode 8A and an output terminal electrode 8B are each formed on at least one of outer peripheral faces of the coupling dielectric block 2. The terminal electrodes 8A and 8B are both formed on one side, outer peripheral face of the dielectric block, or are formed on both end, outer peripheral faces respectively of the dielectric block. This construction permits a sufficient reduction in size of a dielectric filter while retaining desired characteristics.

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Yamaguchi, Japan

Shotaro Hayashi