| 摘要 |
PROBLEM TO BE SOLVED: To perform comparatively accurate temperature compensation without using a large-scale circuit. SOLUTION: An ambient temperature of a surface acoustic wave resonator whose temperature vs. frequency characteristic is expressed by a quadratic function is detected, and a control voltage corresponding to the ambient temperature is generated. The control voltage is changed along a straight line (a) and a straight line (b) having different slopes, corresponding to temperature changes, in a region on the side of temperatures lower than the vertex temperature Tp of the temperature vs. frequency characteristic. The control voltage is changed along a straight line (c) and a straight line (d) having different slopes, corresponding to temperature changes, in a region on the side of temperatures higher than the vertex temperature Tp. COPYRIGHT: (C)2007,JPO&INPIT
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