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RF design and test of a high-directivity high-power waveguide directional coupler for the HEPS



A novel high-directivity high-power waveguide directional coupler (DC) working at 2998.8 MHz is developed for the High Energy Photon Source. It can help the phase control system to obtain a very accurate microwave signal, which is very important to minimize the beam emittance.


The novel reversely placed T-type coupling piece helps to obtain a high directivity. The N-type high-vacuum feedthroughs for vacuum sealing instead of the traditional ceramic plate is beneficial to holding a higher peak power. The simulation and the high-power commissioning are accomplished in the Institute of High Energy Physics (IHEP), while the fabrication and the low-power test are conducted in cooperation with the manufacturer.


Both the single-coupler and the dual-coupler DCs are developed with a directivity of more than 35 dB while keeping the coupling factor within 60±0.5 dB. Finally, 69.4 % of all the fifty-two mass produced DCs have got a directivity of more than 40 dB. Conclusion: The mature manufacturing process for mass production is obtained. The novel high-directivity high-power waveguide DC can be mass produced with an actually internationally leading performance.

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We would like to give our sincere thanks to all the people who are helpful in any stage of the whole development procedure, especially to our cooperating manufacture who solved lots of practical difficulties during the fabrication and test.


Funded by Youth Innovation Promotion Association CAS (2020015).

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Correspondence to Xiang He.

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He, X., Zhang, JR., Liu, JD. et al. RF design and test of a high-directivity high-power waveguide directional coupler for the HEPS. Radiat Detect Technol Methods 6, 137–142 (2022).

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  • HEPS
  • Directional coupler
  • High directivity
  • High power
  • Mass production


  • 29.20.-c