The scattering coefficients of superconducting microwave resonators: I. Transfer-matrix approach

  1. Qi-Ming Chen,
  2. Meike Pfeiffer,
  3. Matti Partanen,
  4. Florian Fesquet,
  5. Kedar E. Honasoge,
  6. Fabian Kronowetter,
  7. Yuki Nojiri,
  8. Michael Renger,
  9. Kirill G. Fedorov,
  10. Achim Marx,
  11. Frank Deppe,
  12. and Rudolf Gross
We describe a unified classical approach for analyzing the scattering coefficients of superconducting microwave resonators with a variety of geometries. To fill the gap between experiment
and theory, we also consider the influences of small circuit asymmetry and the finite length of the feedlines, and describe a procedure to correct them in typical measurement results. We show that, similar to the transmission coefficient of a hanger-type resonator, the reflection coefficient of a necklace- or bridge-type resonator does also contain a reference point which can be used to characterize the electrical properties of a microwave resonator in a single measurement. Our results provide a comprehensive understanding of superconducting microwave resonators from the design concepts to the characterization details.