A low ohmic loss radial superlattice conductor at 15 GHz using eddy current canceling effect

A cylindrical radial superlattice (CRS) structure composed of alternating concentric Al/Permalloy layers is proposed for a low loss radio frequency (RF) conductor. The CRS structure utilizes the eddy current canceling effect by alternating permalloy and non-permalloy layers at the targeted frequency. Theoretical and numerical analyses are presented in the cylindrical coordinate system. Comparing with the conventional planar superlattice, the CRS offers a circular and conformal boundary condition, resulting in better analytical and numerical solutions for the suppression of RF conductor loss. Design procedure is provided. With the new CRS structure, RF resistance is reduced by up to 50 % at 15 GHz comparing to its solid conductor counterpart.