In this work, we applied two electromagnetic models for the characterization of a planar structure including a flat, thick copper conductor. Indeed the first model is consisted by modeling two metal ribbons without bu...In this work, we applied two electromagnetic models for the characterization of a planar structure including a flat, thick copper conductor. Indeed the first model is consisted by modeling two metal ribbons without bulkiness, placed one above the other at a distance of h<sub>2</sub> equal to the thickness of the thick conductor. This approach has been implemented and tested by the iterative method. The results of simulations have been compared with those calculated by the Ansoft HFSS software, and they are in good concordance, validating the method of analysis used. The second model is based on the calculation of the effective permittivity of the medium containing the thick conductor. This medium consists of a metallic region of complex relative permittivity , the rest of this medium is filled with air e<sub>r</sub><sub>2</sub> = 1. The effective permittivity e<sub>eff</sub> calculated from these two relative permittivity e<sub>r</sub><sub>2</sub> and . Comparing the simulation results of this new formulation of the iterative method with those calculated by the software Ansoft HFSS shows that they are in good matching which validates the second model.展开更多
In most studies of microstrip circuits, the majority of researchers assume that the microstrip structures studied have flat metallic conductors of finite widths but without thickness. But in reality these types of str...In most studies of microstrip circuits, the majority of researchers assume that the microstrip structures studied have flat metallic conductors of finite widths but without thickness. But in reality these types of structures integrate metallic copper conductors of different thicknesses. If we neglect this thickness we introduce error in the electrical parameters of the microstrip structure, which affects the effective permittivity, the characteristic impedance, the adaptation of the circuit, the resonance frequency, etc. Given the importance of this parameter (thickness of the metal of micro rubon structures), rigorous electromagnetic modeling of the thick micro rubon line based on the skin effect phenomenon (In fact at high frequency the skin effect phenomenon occurs and the current only flows on the periphery of the conductor) has been proposed to improve the studied electric model and ensure the increase in the precision of the analysis method used: Wave concept iterative process. The good agreement between the simulated and published data justifies the improvement of the model.展开更多
Fabrication of a strong cube texture Ni substrate through thermomechanical process is reported by ORNL research group. Decreasing the substrate thickness, the engineering critical current density will be improved. Rol...Fabrication of a strong cube texture Ni substrate through thermomechanical process is reported by ORNL research group. Decreasing the substrate thickness, the engineering critical current density will be improved. Rolled substrates are electropolished to the final thichness of 100, 80, 50, 40, and 20 μm, respectively. Electropolished substrates are recrystallized at temperatures between 800-1000℃ and in a mixed atmosphere of 4% H2 in 99.99% purity Ar. Orientation mappings of recrystallizated tapes are conducted through an EBSD system mounted on a LEO-1450 SEM. The influence of the substrate thickness on texture of the tape is studied in this paper. Results show that with the decrease of substrate thickness, the texture of the tapes with the same recrystallization process is more and more closed to the exact position of cube orientation.展开更多
文摘In this work, we applied two electromagnetic models for the characterization of a planar structure including a flat, thick copper conductor. Indeed the first model is consisted by modeling two metal ribbons without bulkiness, placed one above the other at a distance of h<sub>2</sub> equal to the thickness of the thick conductor. This approach has been implemented and tested by the iterative method. The results of simulations have been compared with those calculated by the Ansoft HFSS software, and they are in good concordance, validating the method of analysis used. The second model is based on the calculation of the effective permittivity of the medium containing the thick conductor. This medium consists of a metallic region of complex relative permittivity , the rest of this medium is filled with air e<sub>r</sub><sub>2</sub> = 1. The effective permittivity e<sub>eff</sub> calculated from these two relative permittivity e<sub>r</sub><sub>2</sub> and . Comparing the simulation results of this new formulation of the iterative method with those calculated by the software Ansoft HFSS shows that they are in good matching which validates the second model.
文摘In most studies of microstrip circuits, the majority of researchers assume that the microstrip structures studied have flat metallic conductors of finite widths but without thickness. But in reality these types of structures integrate metallic copper conductors of different thicknesses. If we neglect this thickness we introduce error in the electrical parameters of the microstrip structure, which affects the effective permittivity, the characteristic impedance, the adaptation of the circuit, the resonance frequency, etc. Given the importance of this parameter (thickness of the metal of micro rubon structures), rigorous electromagnetic modeling of the thick micro rubon line based on the skin effect phenomenon (In fact at high frequency the skin effect phenomenon occurs and the current only flows on the periphery of the conductor) has been proposed to improve the studied electric model and ensure the increase in the precision of the analysis method used: Wave concept iterative process. The good agreement between the simulated and published data justifies the improvement of the model.
基金Project supported by National High Technonogy ResearchDevelopment Program(2002AA306211 ,2004AA306130)
文摘Fabrication of a strong cube texture Ni substrate through thermomechanical process is reported by ORNL research group. Decreasing the substrate thickness, the engineering critical current density will be improved. Rolled substrates are electropolished to the final thichness of 100, 80, 50, 40, and 20 μm, respectively. Electropolished substrates are recrystallized at temperatures between 800-1000℃ and in a mixed atmosphere of 4% H2 in 99.99% purity Ar. Orientation mappings of recrystallizated tapes are conducted through an EBSD system mounted on a LEO-1450 SEM. The influence of the substrate thickness on texture of the tape is studied in this paper. Results show that with the decrease of substrate thickness, the texture of the tapes with the same recrystallization process is more and more closed to the exact position of cube orientation.
