Novel method to measure unloaded quality factor of resonant cavities at room temperature

  • Ping Wang
  • Jia-Ru Shi
  • Zheng-Feng Xiong
  • Ze-Ning Liu
  • Cheng Cheng
  • Huai-Bi Chen


We demonstrated a novel method to measure the unloaded quality factor (Q factor) of high-Q resonant cavities. This method was used to obtain data with low errors and calculate the unloaded Q factor. This procedure was more reliable than traditional methods. The data required for the method were near the resonant frequency, not at the half-power points of the reflection coefficient curve or Smith chart. We applied the new method to measure a resonant cavity with an unloaded Q factor of ~ 100,000, obtaining good agreement between the measured and theoretical results.


Resonant cavity Q factor LRC circuit Coupling coefficient 


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Copyright information

© Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Chinese Nuclear Society, Science Press China and Springer Nature Singapore Pte Ltd. 2018

Authors and Affiliations

  • Ping Wang
    • 1
    • 2
  • Jia-Ru Shi
    • 1
    • 2
  • Zheng-Feng Xiong
    • 3
  • Ze-Ning Liu
    • 1
    • 2
  • Cheng Cheng
    • 1
    • 2
  • Huai-Bi Chen
    • 1
    • 2
  1. 1.Department of Engineering PhysicsTsinghua UniversityBeijingChina
  2. 2.Key Laboratory of Particle and Radiation Imaging of Ministry of EducationTsinghua UniversityBeijingChina
  3. 3.Northwest Institute of Nuclear TechnologyXi’anChina

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