Development of high-power and ultra-high-vacuum waveguide coupler   working at C/X band
  Waveguide directional couplers working at 5.712/11.9924 GHz are developed. Even holes symmetrical to the structure are drilled along the central line of the narrow-wall of waveguide, which are used to couple the electromagnetic power from the main-waveguide to the sub-waveguide. The final prototypes have got satisfactory performances of high-power, ultra-high-vacuum and high-directivity. The microwave measurement results are also qualified. 
Xiang He, Fengli Zhao, Xiangjian Wang
physics.acc-ph