| 摘要 |
PROBLEM TO BE SOLVED: To reduce the change of the oscillation frequency of an oscillator due to its temperature change, thereby normally performing a PLL operation and stabilizing the oscillation frequency. SOLUTION: The oscillator comprises a resonance circuit 41 having a varactor diode 41b operative with an oscillation frequency setting tuning voltage applied to its cathode, oscillation transistors 11, 12 having bases coupled with the resonance circuit 41, diodes 27, 28 coupled at least between the bases of the oscillation transistors 11, 12 and the ground to avoid the electrostatic breakdown of the transistors 11, 12, and a tuning voltage generator circuit 33 for generating a tuning voltage by a phase locked loop. Further, a temperature compensation circuit 35 is formed for dividing a specified voltage into a division voltage changing in the same direction as the increasing-decreasing direction of the tuning voltage. The anodes of the diodes 27, 28 are grounded and the divided voltage is applied to the cathode of the diode 27. COPYRIGHT: (C)2003,JPO
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