ISSN:
1572-9605
Keywords:
Surface impedance of high-T c superconductor
;
thin films
;
penetration depth
;
critical current
Source:
Springer Online Journal Archives 1860-2000
Topics:
Electrical Engineering, Measurement and Control Technology
,
Physics
Notes:
Abstract This paper defines an effective microwave surface resistance $$R_{\text{s}}^{{\text{eff}}}$$ for the nonuniform distribution of microwave surface resistance R s in the strip of a microstrip. It is proved that $$R_{\text{s}}^{{\text{eff}}}$$ is equivalent to the expression of R s used in experiments, and that the $$R_{\text{s}}^{{\text{eff}}}$$ is dominated by the edge part, i.e., the area of width λ2/2t from the strip edge, where λ is the magnetic penetration depth and t is the film thickness. Under the assumption that $$R_s \sim \left( {H_{{\text{rf}}}^y } \right)^n$$ where $$H_{{\text{rf}}}^y$$ is the component of rf magnetic field along the film thickness and n is an integer, the ratio of the contributions of the edge part and the rest of the strip to $$R_s^{{\text{eff}}}$$ is calculated by using an approximate analytical expression of the surface current density distribution J s in the strip and $$H_{{\text{rf}}}^y$$ calculated by the London equation. The effect of film's edge on R s was studied using a microstrip resonator. It is found that the perfectness of the edge could affect the magnitude of the power dependence of R s significantly, which agreed with our analysis.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1022696220632
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