摘要 |
A temperature-compensated rod resonator, comprising a housing (10) having electrically conducting walls, including at least one electrically conductive resonator rod (14) extending from a bottom wall (11) towards a top wall (13), a temperature-compensating plate (20) located adjacent to said top wall (13) and coupling means (150, 151) for transferring electromagnetic energy to and from the resonator. The plate (20) is adapted to change its geometrical configuration in response to temperature variations. The temperature-compensating plate is a bimetallic plate (20) having a larger diameter than the resonator rod (14). A central portion (21) of said bimetallic plate (20) is secured to the upper end of the resonator rod (14), whereby the bimetallic plate, in conjunction with the adjacent top wall (13) defines a capacitance, which has a dominating influence on the resonance frequency. A pheripheral portion (22) of the bimetallic plate (20) is permitted to be freely deflected in response to the temperature variations, whereby the resonance frequency is changed so as to counteract temperature-induced dimensional changes of the housing (10) and the resonator rod (14). |