W波段回旋行波管输出结构的优化设计*

在回旋行波管的设计过程中,输出结构性能的高低直接影响到整管增益的高低以及输出功率的大小。采用切比雪夫渐变波导作为耦合输出段,通过对轮廓线的计算程序进行改进,将中心频率作为可变量进行了修正。仿真结果表明,长度为75mm改进后的切比雪夫渐变结构不仅能抑制工作模式向杂模TE02和TE03的耦合,还能有效减少工作模式的反射。在整个工作频段内,杂模TE02和TE03的耦合系数分别低于-33dB和-65dB,TE01模的反射系数低于-20dB,TE01模的传输系数高于-0.01dB。

An Optimal Design of Output Structure for W-Band Gyro-TWT

An improved output structure which adopts Chebyshev waveguide, working in TE01 mode, has been de-signed for W band gyrotron traveling wave tube(Gyro-TWT). The contour of the Chebyshev waveguide is got through theoretic analysis and numerical computation in Matlab. On the basis of optimized results from the CST, the reflection coefficient of TE01 is less than -20dB and transmision coefficient of TE01 is more than -0. 01dB in the whole working band. Not only does the improved Chebyshev waveguide suppress spurious modes, but it also has good performance on transmision working modes with acceptable length.