| 摘要 |
<p>PROBLEM TO BE SOLVED: To suppress the level of spurious radiation to be low, and secure stable operation without using any additional component such as a spurious reducing filter or the like. SOLUTION: In an anode 10 arranged in the center portion of a cathode 3, plural radial vanes B1, B19 and annular straps S1 to S4 are arranged as a resonator structure. In such an anode 10, by spreading the space volume of an end space 15 up to 1.0 cm<3> , the resonance frequency of a (π-1) mode (higher order mode) is adjusted so as to be in a range ofπmode frequency±300 MHz. This frequency shift can be executed by such a method as changing the cut positions of the straps S1 to S4, bending the end portions of the cut portions, or the like. Preferably, the resonance of the (π-1) mode is coupled with an external circuit in coupling coefficientβ:0.2 or more, and in sharpness QL:75 or more.</p> |
