Conversion of the anomalous skin effect to the normal one in thin-film metallic microwave systems

Abstract

Abstract The main morphology parameters of microstrip Au/i-GaAs coplanar microwave transmission lines (CTL) with length l W influenced on its skin depth resistance R wide of δ and inductivity L are defined at frequencies f > 10 GHz. Due to the sizes of Au grains formed CTL d x < 130 nm, surface roughness h ≥ 400 nm and fractal character of its lateral distribution in CTL plane, the features in electron scattering processes arise and lead to the formation of significant size effects in local approximation. Necessary condition l ball < d x ≪ δ for transition from anomalous skin effect to normal skin effect start up owing to limited grain size d x  ≪ δ. Moreover, in local approximation nonlinear dependence of R from l W is provided by fractal geometry of relief and grain lateral distribution. Nonlinear dependence of L from l W is provided by not only fractal features of CTL two-dimensional surface but fractal features of three-dimensional Au grain distribution over skin depth wide.