| 摘要 |
PROBLEM TO BE SOLVED: To provide a small and inexpensive crystal oscillator that is low in phase noise and whose characteristics are stable even at a high frequency of several hundred MHz or higher since there is the problem that, in a conventional crystal oscillator using a transformer in order to suppress phase noise, its shape becomes large and it leads to an increase in costs, and its characteristics become unstable at a high frequency of several hundred MHz or higher. SOLUTION: The crystal oscillator is configured to obtain oscillation output from both ends of a resistor by inserting a circuit, in which aλ/4 transformer and the resistor are connected in series, into an oscillating closed loop instead of a transformer. Each slit is provided by forming theλ/4 transformer with a microstrip line whose electric length is longer thanλ/4 while connecting each slit via a capacitor. Consequently, it facilitates the adjustment of an impedance of theλ/4 transformer and an output frequency. COPYRIGHT: (C)2008,JPO&INPIT
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