Abstract: The problem that the response frequency of the klystron will be shifted after long-term operation
and the analog phase-locked loop cannot work at the optimal frequency of the system has been solved by using of
digital phase-locked loop technology to achieve high-precision and adjustable frequency output performance
within a certain bandwidth. A power amplitude control circuit is added after the shifter to ensure that the output
power of the linear amplifier will not be affected by the phase adjustment. A waveform control unit based on the
combination of digital-to-analog conversion (D/A) technology and microwave electrically adjustable technology
is designed to solve the problem that the output waveform of the exciter is uncontrollable. Through the above
three improvements, the performance optimization design of the microwave exciter of the LHCD system on
HL-2M tokamak has been completed. 

Key words: LHCD, Microwave exciter, Digital phase lock technology, Power amplitude control, Output waveform control 

摘要： 使用数字锁相环技术实现一定带宽内高精度可调节的频率输出，解决了速调管长期工作后响应频率 发生偏移，模拟锁相环无法工作在系统最佳频率的问题；在移相器后增加功率幅度控制电路，保证了线性放大器 的输出功率不会受到相位调节的影响；设计了一种基于数模转换(D/A)技术与微波电调技术相结合的波形控制单元，解决了激励源输出波形不可控的问题。通过以上三方面的改进，完成了 HL-2M 装置 LHCD 系统微波激励源 的性能优化设计。 

关键词: 低混杂波电流驱动, 微波激励源, 数字锁相技术, 功率幅度控制, 输出波形控制