We discuss calibration issues in wideband (2-20 GHz) surface impedance measurements in a cryogenic and high- magnetic-field environment. We show that, in the case of mea- surements taken on superconducting thin films, the substantial impossibility of a full, three-standard calibration can be partially overcome by exploiting appropriate approximations and the basic properties of superconductors. We discuss a modification of the so-called “short-only” calibration, in order to increase the accuracy of the measurements. We check experimentally the applicability of the approximations at the ground of the method, and we report sample measurements of the surface impedance of a MgB2 superconducting film.
Pompeo, N., S., S., Torokhtii, K., Silva, E. (2015). Cryogenic Microwave Wideband Measurements of Superconducting Thin Films. In Proceedings of I2MTC, 2015 IEEE International Instrumentation and Measurement Technology Conference, Pisa, May 11-14 (2015) [10.1109/I2MTC.2015.7151294].
Cryogenic Microwave Wideband Measurements of Superconducting Thin Films
POMPEO, NICOLA;TOROKHTII, KOSTIANTYN;SILVA, Enrico
2015-01-01
Abstract
We discuss calibration issues in wideband (2-20 GHz) surface impedance measurements in a cryogenic and high- magnetic-field environment. We show that, in the case of mea- surements taken on superconducting thin films, the substantial impossibility of a full, three-standard calibration can be partially overcome by exploiting appropriate approximations and the basic properties of superconductors. We discuss a modification of the so-called “short-only” calibration, in order to increase the accuracy of the measurements. We check experimentally the applicability of the approximations at the ground of the method, and we report sample measurements of the surface impedance of a MgB2 superconducting film.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
