Zhang Xiaoping, Li Yangmei, Li Zhiqiang, Zhong Huihuang, Qian Baoliang
College of Optoelectronic Science and Engineering, National University of Defense Technology, Changsha 410073, China.
Rev Sci Instrum. 2015 Oct;86(10):104703. doi: 10.1063/1.4934246.
In order to promote the power conversion efficiency of a magnetically insulated transmission line oscillator (MILO) and obtain microwaves in dual bands, an axially extracted C-band virtual cathode oscillator (VCO) with multiple resonant cavities is introduced to partially utilize the load current of an S-band MILO. The formed novel dual-band high power microwave source called MILO and VCO is investigated with simulation and experimentally. A dual-band radiation antenna is designed to effectively radiate microwaves generated by the MILO and the VCO, respectively, while avoiding them being influenced by the microwave reflection and diffraction. The preliminary experimental results measured by the dual-band diagnostic system show that both the MILO and the VCO operate normally under repeated shots. A microwave of 2.1 GHz, 1.70 GW is generated from the MILO and a 0.37 GW microwave at frequencies of 4.1 GHz and 3.8 GHz is generated from the VCO under the condition of about 440 kV and 35 kA. Compared with a single MILO (10.6%), a MILO and VCO achieves higher total power and efficiency (13.4%) in both S and C bands, indicating that the load current of the MILO partially couples into the beam-wave interaction in the VCO and then contributes to the output microwaves. However, more works are needed regarding the spectrum purification of the VCO and promotion of the output power of both the MILO and the VCO.
为了提高磁绝缘传输线振荡器（MILO）的功率转换效率并获得双频段微波，引入了一种具有多个谐振腔的轴向提取C波段虚阴极振荡器（VCO），以部分利用S波段MILO的负载电流。对所形成的名为MILO和VCO的新型双频段高功率微波源进行了仿真和实验研究。设计了一种双频段辐射天线，以分别有效辐射由MILO和VCO产生的微波，同时避免它们受到微波反射和衍射的影响。由双频段诊断系统测量的初步实验结果表明，MILO和VCO在重复脉冲下均能正常运行。在约440 kV和35 kA的条件下，MILO产生了2.1 GHz、1.70 GW的微波，VCO产生了频率为4.1 GHz和3.8 GHz、功率为0.37 GW的微波。与单个MILO（10.6%）相比，MILO和VCO在S波段和C波段均实现了更高的总功率和效率（13.4%），这表明MILO的负载电流部分耦合到VCO中的束波相互作用中，进而有助于输出微波。然而，关于VCO的频谱纯化以及MILO和VCO输出功率的提升，还需要开展更多工作。
