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Presents a study which examined the microwave properties of YBa[sub2]Cu[sub3]O[sub7-δ] high-transition-temperature superconducting (HTS) thin films measured by the power transmission method. Overview of previous studies on HTS thin films; Details of sample preparation techniques and calculation of complex conductivity; Considerations for the computation of magnetic susceptibility and surface resistance.

Dielectric constants of microwave subtrates are required in the design of superconducting microwave circuits at various temperatures. In this paper, we report the results of a study of the complex permittivity of the newly developed lanthanum aluminate (LaAlO3) substrate, in the 20 to 300 K temperature range at frequencies from 26.5 to 40.0 GHz. The value of the complex permittivity was obtained by measuring the sample scattering parameters using a microwave waveguide technique. It is observed that, while the dielectric constant did not change appreciably with frequency, its value decreased by approximately 14 percent from room temperature to 20 K. [ABSTRACT FROM AUTHOR]