| 摘要 |
A apparatus for tuning a resonant cavity of a magnetron is provided which prevents undesired frequency fluctuation during thermal cycling or vibration. The magnetron has an axially disposed resonant cavity comprising a plurality of radially disposed anode vanes. Alternating ones of the vanes are electrically connected together by a first and a second strap, respectively. The tuning apparatus comprises a tuner shaft having a threaded outside diameter, a vertical gear having a threaded inside diameter engaging the threaded outside diameter of the tuner shaft, and a worm gear engaging the vertical gear. Rotation of the worm gear translates to axial movement of the tuner shaft. A ceramic cylinder is coupled to the tuner shaft at an end adjacent to the resonant cavity, and extends into a space defined between the first and second straps by the axial movement of the tuner shaft. Disposition of the ceramic cylinder within the space alters capacitance measurable between the straps. An axial loading force is applied to the tuner shaft to prevent undesired axial movement of the tuner shaft by spring washers mechanically coupled to the tuning shaft. A base plate is secured to the tuning shaft, and the spring washers extend between the baseplate and an end portion of the magnetron. The spring washers may be disposed in series, or a plurality of stacks of spring washers may be disposed in parallel with the stacks disposed in series.
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