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Updated: Apr 20, 2026

Fabrication and Characterization of Superconducting Resonators
Published on: May 21, 2016
Two-slot coiled coaxial cable resonator: reaching critical coupling at a reduced number of coils
Gerald Hefferman1, Zhen Chen1, Tao Wei1
1Department of Electrical, Computer, and Biomedical Engineering, University of Rhode Island, Kingston, Rhode Island 02881, USA.
Abstract:
This paper reports the experimental demonstration of a coiled coaxial cable resonator capable of meeting the critical coupling condition using a reduced number of coils relative to previously reported coiled resonators. By introducing a second slot along the length of the device, a two-slot coiled coaxial cable resonator was fabricated and critical coupling observed at 22 turns. An additional device with one-slot, but otherwise identically constructed, was also fabricated. After 44 turns, the one-slot device had yet to reach critical coupling. An ultrahigh signal-to-noise ratio (greater than 70 dB) was observed at critical coupling of the two-slot device. This reduction in number of slots necessary to reach critical coupling, and the corresponding reduction of physical length of the device, makes this demonstration of the control of critical coupling a potentially important step towards the successful application of coiled coaxial cable resonators to microwave communication and robust sensing applications.
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