基于宽禁带光导半导体的固态光导微波源是高功率微波产生的一种新途径，该方案具有功率密度高、频带范围宽等特点，且其低时间抖动特性使其在功率合成方面具有巨大潜力，利用光波束形成网络构建光导微波有源相控阵是光导微波器件迈向实用的重要途径。分析了光导微波相控阵系统原理，设计了光导微波真延时网络架构，并构建了差分真延时相控阵和考虑相位随机误差的真延时相控阵的理论模型，对影响功率合成和波束扫描的关键因素开展定量分析和仿真验证。结果表明，对于发射1 GHz信号的n×10阵列，延时均方差在10 ps以下时，指向偏差小于0.13°，峰值增益损耗小于2%；延时步进精度在10 ps以下时，指向偏差小于0.2°，峰值增益损耗小于0.03%。由此提出延时精度指标，为未来更高功率、更大规模的光导微波合成技术发展提供参考。

Radio frequency/microwave-directed energy sources using wide bandgap SiC photoconductive semiconductors have attracted much attention due to their unique advantages of high-power output and multi-parameter adjustable ability. Over the past several years, benefitting from the sustainable innovations in laser technology and the significant progress in materials technology, megawatt-class output power electrical pulses with a flexible frequency in the P and L microwave wavebands have been achieved by photoconductive semiconductor devices. Here, we mainly summarize and review the recent progress of the high-power photonic microwave generation based on the SiC photoconductive semiconductor devices in the linear modulation mode, including the mechanism, system architecture, critical technology, and experimental demonstration of the proposed high-power photonic microwave sources. The outlooks and challenges for the future of multi-channel power synthesis development of higher power photonic microwave using wide bandgap photoconductors are also discussed.

通过理论计算、数值仿真和实验验证的方法，研究了一台峰值功率数十GW、重复频率5 Hz的重复频率高功率脉冲驱动源，命名为“HEART-50”。该脉冲驱动源由充电电源、初级开关、脉冲形成线、主开关、阻抗变换线，以及假负载构成。首先介绍了HEART-50重复频率高功率脉冲驱动源整体设计思路；其次，对基于混合液体介质的高功率脉冲形成线和气体介质主开关进行了数值分析，并对其全电路工作能力进行了仿真分析；最后，对研制的HEART-50重复频率高功率脉冲驱动源进行了实验验证。结果表明，脉冲驱动源能够输出峰值电压520 kV，脉冲宽度约90 ns，脉冲上升沿小于25 ns，重复频率5 Hz的准方波电脉冲，峰值电功率约为25.3 GW，且具有较好的运行稳定性。

介绍了一种微秒长脉冲有磁场的真空二极管界面的设计和实验结果。采取了三种措施来抑制沿面闪络：一是阴极电子束挡板，用来拦截来自阴极和电子束漂移管的回流电子束；二是接地屏蔽板，使电场等势线和界面成约45°角，使阴极三结合点处发射的电子远离绝缘板；三是降低阴极三结合点处的场强，并使用一悬浮电位的金属环阻止电子倍增过程。计算了二极管内电场、磁场分布和电子束的运动轨迹并据此优化了真空界面的结构，实验验证了该二极管真空界面可以在400 kV、800 ns条件下正常工作，可以支持长脉冲高功率微波器件的研究。

随着微波光子学的发展，新型光导微波技术利用高重频脉冲簇激光，入射到线性光导半导体器件中产生可调谐高功率电磁脉冲的方式受到广泛关注。SiC光导半导体开关（PCSS）具有高击穿场强，高饱和载流子速率，高抗辐射能力，高热传导率和高温工作稳定性等优点，是产生高重频、高功率、超短脉冲的重要固态电子器件。介绍了一种基于钒补偿半绝缘4H-SiC PCSS的MHz重复频率亚纳秒脉冲发生器。该发生器采用1 MHz，1030 nm可调谐光脉冲宽度的激光簇驱动源，4H-SiC PCSS的厚度为0.8 mm。整系统可得到最大输出电功率176 kW、最小半高宽约为365 ps的MHz重频短脉冲。

Narrowband microwave generation with tuneable frequency is demonstrated by illuminating a photoconductive semiconductor switch (PCSS) with a burst-mode fibre laser. The whole system is composed of a high-power linearly polarized burst-mode pulsed fibre laser and a linear-state PCSS. To obtain a high-performance microwave signal, a desired envelope of burst is necessary and a pulse pre-compensation technique is adopted to avoid envelope distortion induced by the gain-saturation effect. Resulting from the technique, homogenous peak power distribution in each burst is ensured. The maximum energy of the laser burst pulse reaches 200 μJ with a burst duration of 100 ns at the average power of 10 W, corresponding to a peak power of 4 kW. When the PCSS is illuminated by the burst-mode fibre laser, narrowband microwave generation with tuneable frequency (0.80–1.12 GHz) is obtained with a power up to 300 W. To the best of the authors’ knowledge, it is the first demonstration of frequency-tuneable narrowband microwave generation based on a fibre laser. The high-power burst-mode fibre laser reported here has great potential for generating high-power arbitrary microwave signals for a great deal of applicable demands such as smart adaptive radar and intelligent high-power microwave systems.

强流脉冲电子束源是高功率微波系统的核心部件之一，针对未来应用需求，亟需从绝缘、束流输运和热管理等多个方面提升强流束源技术性能。介绍了国防科技大学在高功率微波源用强流真空电子束源方面的研究进展。针对高功率微波管保真空需求，基于陶瓷金属钎焊，设计并研制了一种强场陶瓷真空界面，耐压大于600 kV、平均绝缘场强达到44 kV/cm、耐受脉宽大于80 ns，重复频率运行稳定；研制了一种基于SiC纳米线的强流电子束源冷阴极，在90 kV/cm的场条件下获得了1.17 kA/cm²的束流密度，相比传统天鹅绒阴极，SiC纳米线阴极的宏观电稳定性、发射均匀性及运行寿命均得到显著提高；针对相对论返波管，研制基于螺旋水槽型的强流电子束收集极，克服了高比能和低流速的矛盾，耐受热流密度达到10¹² W/m²，能够满足系统长脉冲、高重复频率运行要求。