975MHz高功率移相器的研制

摘要

移相器是直线加速器射频系统中的关键部件之一,为确保大功率加速器稳定运行,所用移相器需承受高射频功率的传输.基于改变传输线长度的移相方式,本文设计了通过电长度调节和3 dB混合耦合调谐的复合式结构,通过分析射频性能优化各部分结构,并对整个移相器结构进行模拟计算,研制了一种高功率移相器.实验测试结果表明,该移相器工作频率为975 MHz,在工作频率处驻波比为1.02,可实现0°～360°线性移相,整个移相范围内插入损耗小于0.45 dB.%Phase shifter plays a very critical role in the RF system of linear accelerators.To ensure the stable operation of high power accelerators,phase shifters which can withstand high RF power should be adopted.Based on the phase-shifting method of changing transmission length,a composite structure which can be adjusted by changing electrical length and tuned by 3 dB hybrid coupler was designed.After the optimization of each part with performance analysis and the simulation of the entire structure,a high power phase shifter was developed.The test results show that the operating frequency is 975 MHz,and the VSWR (voltage standing wave ratio) is 1.02 at this frequency.The output phase can be changed between 0° and 360° linearly,and in the whole phase shifting range the insertion loss is below 0.45 dB.