PURPOSE: To provide high-accuracy frequency stability over a wide temperature range by changing the frequency of an oscillator using a first surface acoustic wave(SAW) element into a voltage, and controlling the oscillation frequency of an oscillator using a second SAW element corresponding to that voltage.
CONSTITUTION: When the frequency to be changed corresponding to the temperature of an oscillator 11 for temperature compensation is inputted to a frequency/ voltage converter 12, the converted voltage is changed corresponding to the temperature as well and inputted to a VCO 13. The VCO 13 is constituted by adding a coil 13g, capacitor 13f and variable diode 13e to a Colpitts oscillator similar to the oscillator 11. Since the element 13g is formed by the same monocrystal piezoelectric material as an element 11a, the VCO 13 and the oscillator 11 are provided with approximated temperature characteristics. Therefore, the voltage for temperature compensation is exactly and easily provided and the high-accuracy frequency stability can be provided over the wide temperature range.
NAKAMURA KENZO
SHINOHARA YOSHINORI
