PURPOSE: To prevent the temperature fluctuation of the resonance frequency by a method wherein the fluctuation of the resonance frequency of the cavity resonator due to temperature change is set in such a way as to cancell the fluctuation of the frequency shift of the hydrogen storage sphere due to temperature change.
CONSTITUTION: An end plate 15, an end plate 16 and resonator cylinders 6 are thermally formed in one body by ring members 19 and 20, and there is no possibility that the temperature difference between the resonator cylinders 6 and a hydrogen storage sphere 4 is widened greater. The temperature change of the resonance frequency fc in this resonator system is represented at a figure of ΔTc(t)ΔTb(t) by Formula I provided that, ΔTc: temperature fluctuation of the resonator cylinder, ΔT: temperature fluctuation of the hydrogen storage sphere. The second member of the Formula I becomes ∂r/∂T>0, because the hydrogen storage sphere 4 has been constituted of quartz. On the other hand, when the temperature expansion coefficient α of the resonator cylinders 6 forming a cavity resonator 5 is set at a negative value, the ∂fCo/∂T becomes a positive value from the Formula I . Therefore, the first and second members of the Formula I flucturate in such a way as to cancel the temperature flucturation. Accordingly, the resonance frequency fc can be extremely stabilized to temperature change by properly selecting the value of the temperature expansion coefficient α of the resonator cylinders 6.
HORIKIRI SHINJI
KITAYAMA MITSUMASA
MORIKAWA KATAO
OOTA YASUSADA
YUSEISHO DENPA KENKYUSHO