采用2.5维粒子模拟软件对改进型低阻类膜片加载同轴渡越时间振荡器进行了研究。研究结果表明：提取腔工作于类π模场时，具有较高的束波互作用效率；引入渐变型输出波导，提高了提取腔内微波向外耦合输出的能力；通过加载感性支撑杆，一方面对金属膜片起支撑固定作用，另一方面可以及时将膜片上的感应电荷导流至接地外筒、从而降低间隙附近的空间电荷效应，以增加可提取的束动能。经优化设计，该结构在二极管电压为530 kV，二极管电流为12.9 kA、外加导引磁场为0.5 T的条件下，输出微波功率2.74 GW，微波频率7.76 GHz，束波功率转换效率达40%。

An improved low-impedance transit-time oscillator loaded with washer-like structure is proposed and investigated by using the 2.5D fully electromagnetic particle-in-cell code. The extractor operates at π-like mode, which is advantageous to keep a high efficiency of the beam-wave interaction. Due to the adoption of the tapered output waveguide, the microwave can be extracted more effectively. Loading inductive metal rods can not only support the washers, but also ground the DC induced charge in the washers. The optimized simulation results show that a 7.76 GHz, 2.74 GW microwave can be obtained with an efficiency of 40% under the condition of the diode voltage 530 kV，the current 12.9 kA and the guiding magnetic field 0.7 T.