| 摘要 |
PROBLEM TO BE SOLVED: To provide a magnetostatic wave oscillator automatically adjusting the oscillation frequency of a magnetic circuit for a magnetostatic wave element by automatically controlling current caused to flow to an exciting coil 10 and an FM coil 11 when the strength of a magnetic field fluctuates by arranging an element for detecting a fluctuation in the strength of the magnetic field in an air gap. SOLUTION: The magnetic circuit for a magnetostatic wave element is formed so as to provide a permanent magnet and an air gap for arranging a package for an oscillation circuit including the magnetostatic wave element between a magnetic pole piece attached to one pole of the permanent magnet, and a magnetic pole piece connected via an external yoke for confining a magnetic flux in the other pole. The circuit is provided with: a coil for adjusting the strength of the magnetic field between the pole pieces by causing current to flow; a control circuit for controlling the value of the current caused to flow to the coil; a detection element for detecting the fluctuations of the strength of a magnetic field arranged in the air gap; and a detecting means for detecting the fluctuations of the strength of a magnetic field that occurs in the air gap and outputting the detection signal to the control circuit. The control circuit adjusts a current value caused to flow to the coil on the basis of the detection signal. COPYRIGHT: (C)2007,JPO&INPIT
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