Theoretical study on lowering loss of skin effect suppressed multi-layer transmission line with positive/negative (Cu/NiFe) permeability materials for high data-rate and low delay-time I/O interface board

Abstract

This paper proposes a new application of skin effect suppression technology for long wiring on high-speed & low-delay I/O board. This proposal will overcome the difficulty of further reducing the transmission losses on the I/O board with vert >vert 50 Gb/s data rate. In previous research, it was demonstrated that suppression of the skin effect by electroplated conductor/magnetic multi-layer, and estimated that the degree of transmission loss decrease at 16 GHz would be 5 %. A major challenge in this paper is to propose an electromagnetic field calculation theory for rectangular multi-layer transmission line, verify it under the same conditions, clarify a lower loss structure by changing thickness of each layer. Also it is expanded to low loss design technology. Cu and NiFe were selected as metal conductor material and negative permeability magnetic material, respectively. The Cu and NiFe films are alternately stacked to form the multi-layer. The top and bottom surface layers are Cu layers. The loss suppression was compared under the following conditions. 1) Total number of layers was 33 and total thickness was 12.67 μm by a constant ratio, Cu: tN = 0.51μm and NiFe: tF = 0.25μm. 2) Optimal stacking determined by changing the thickness of each layer. Compared to conventional thickness by a constant ratio 1), in our proposal 2), we estimated that the loss would dropped to 92% in optimal thickness. By offsetting the phase change of current density, a lower loss structure could be determined. Compared with Cu conductor, the top and bottom surface current densities become low, and depth center current density becomes slightly high for the multi-layer, showing the skin effect is suppressed.

A Novel Approach on the Unipolar Axial Type Eddy Current Brake Model Considering the Skin Effect

“…Like Lenz's law, eddy current, which has a high frequency at a particular volume, causes magnetic induction in the opposite direction to the primary magnetic field, as a result, directing the electrons to one side of the conductor [32]. Skin effects can occur in conductors used for high-frequency transmission lines [33]. Skin effects can also occur in conductors that move through the magnetic field, hence, the changes in the magnetic fields are quite significant, such as in an electric motor [34,35] or generator [35].…”

Line loss localization diagnosis and management measures of station area combined with data mining

“…At present, problems such as line loss anomalies in substation areas are widespread, and their investigation still relies on the experience of operation and maintenance personnel, which not only greatly increases the workload but also results in the situation that some anomalies are difficult to find, leading to power loss. Therefore, how to effectively utilize the data between the systems, deepen the data analysis, and accurately lock the abnormal users has become an urgent problem to be solved [7][8].…”

Radio-Frequency Conductivity Evaluation Method Based on Surface/Interface Scattering of Metallic Coatings

“…Consequently, when measuring the radio frequency conductivity of conductive coatings with varying thicknesses at different frequencies, it is crucial to consider the relationship between the coating thickness and three times the skin depth corresponding to the frequency. Therefore, the RF conductivity of the conductive coating for a specific rough surface in a dual-layer conductive structure should be evaluated based on two conditions: (a) constructing a reasonable surface model for the rough coating to depict the surface roughness and then calculating the extra power loss of the input electromagnetic wave induced by the rough surface, and (b) considering the correlation between the coating thickness and three times the skin depth associated with the test frequency to deduce the attenuation and reflection processes of the electromagnetic waves within the sample, and establishing a link between the coating's conductivity and the sample's effective conductivity [27,28].…”