The present invention relates to a dielectric resonator device which may be used as a filter or an oscillator in microwave regions.
In FIG. 1 there is shown a conventional dielectric resonator device in which a dielectric resonator element A is mounted on an inner base wall B1 of a shield casing B via a support or pedestal C. The resonator element A is connected with the upper end of the support C by means of an adhesive layer D. The support C is connected with the base wall B1 by an adhesive layer E. This conventional arrangement has a drawback that the adhesive layers D and E can not often attend a sufficient supporting force for the resonator assembly.
In order to improve the supporting strength of the resonator there has recently been proposed another arrangement as shown in FIG. 2. In this arrangement, the resonator element A and the support C are respectively provided with inner bores A1 and C1 along the axes thereof. Through the inner bores A1 and C1 a fixing bolt F is inserted. The bolt F has a head portion F1 engaged with the upper surface of the resonator element A and a screw portion F2 extended through a through hole which is provided in the base wall B1. By threading a nut G over the screw portion F2 the resonator element A and the support C are fastened to each other and then on the base wall B1.
In such arrangements as illustrated in FIGS. 1 and 2, when the resonator device is operated, the resonator element A is self-heated with the resonance thereof. In particular, when the resonator is actuated with higher power, the higher the operation frequency is the larger the heat release value in the resonator element. Since both of the arrangements mentioned above have a poor heat dissipation capacity, they have a disadvantage that the resonance frequency of the resonator may be easily varied. For example, when the resonator is actuated with RF power having the input power of 50 Watt and the resonance frequency of 870 MHz, the temperature increment up to 125.degree. C. is measured on the outer surface of the resonator and the temperature increment up to 200.degree. C. on the inner portion of the resonator. This results in that the resonance frequency of the resonator is decreased by about 10%.