旨在设计一支新型、耦合度可调、连续波型高功率输入耦合器，外部品质因数的调节范围为1.5×105~2×106，以适应先进光源技术研发与测试平台超导电子直线加速器束流试验装置不同束流模式下的需要。这是国内首次开展耦合度可调式连续波型高功率输入耦合器的研制。采用HFSS三维电磁仿真软件完成了耦合器的高频结构设计，对耦合器的微波传输、场分布进行了计算; 同时采用CST微波工作室对不同内导体天线插入深度下耦合器的外部品质因数进行了仿真计算，结合650 MHz 2单元超导腔进行了耦合度调节实验，仿真计算与实验测试结果基本一致。

This paper aims to design a new 650MHz variable fundamental power coupler. The external quality factor Qe ranges from 1.5×105 to 2×106 to meet the requirements of different current modes of the Beam Test Facility of PAPS (Platform of Advanced Photon Source Technology R&D). This is the first time to develop a variable continuous wave type power coupler in China. In this paper, the RF transmission and field distribution of the coupler are calculated by HFSS three-dimensional electromagnetic software. The external quality factor at different antenna penetration depth is simulated by CST microwave studio. The penetration depth adjusting experiment is carried out by integrating with a 650 MHz 2-cell superconducting cavity. The simulated and measured results of Qe agree well with each other.