The choice of the UHV lines depends on surface electric field of the bundle conductors.Based on existing calculation methods,the optimized charge simulation method is used to calculate the conductors' surface elec...The choice of the UHV lines depends on surface electric field of the bundle conductors.Based on existing calculation methods,the optimized charge simulation method is used to calculate the conductors' surface electrical field of±800 kV UHVDC transmission lines in this paper.During calculation,the offset distance is set as the variance of the objective function,the position and the quantity of the simulation charges are optimized with the gold section method,and the surface electrical field is calculated when the charge is in the optimal position.The result shows that the distribution of the surface electrical field and its maximal value can be calculated accurately with this method,although less number of simulation charges is used in this proposed method and the calculation is simple.展开更多
A novel approach devoted to achieving ultra-wideband radar cross section reduction(RCSR) of a waveguide slot antenna array(WGSAA) while maintaining its radiation performance is proposed. Three kinds of artificial ...A novel approach devoted to achieving ultra-wideband radar cross section reduction(RCSR) of a waveguide slot antenna array(WGSAA) while maintaining its radiation performance is proposed. Three kinds of artificial magnetic conductors(AMCs) tiles consisting of three types of basic units resonant at different frequencies are designed and arranged in a novel quadruple-triangle-type configuration to create a composite planar metasurface. The proposed metasurface is characterized by low radar feature over an ultra-wideband based on the principle of phase cancellation. Both simulated and measured results demonstrate that after the composite metasurface is used to cover part of the antenna array, an ultrawideband RCSR involving in-band and out-of-band is achieved for co-and cross-polarized incident waves based on energy cancellation, while the radiation performance is well retained. The proposed method is simple, low-cost, and easy-tofabricate, providing a new method for ultra-wideband RCSR of an antenna array. Moreover, the method proposed in this paper can easily be applied to other antenna architectures.展开更多
基金Project Supported by National Natural Science Foundation of China(90510015).
文摘The choice of the UHV lines depends on surface electric field of the bundle conductors.Based on existing calculation methods,the optimized charge simulation method is used to calculate the conductors' surface electrical field of±800 kV UHVDC transmission lines in this paper.During calculation,the offset distance is set as the variance of the objective function,the position and the quantity of the simulation charges are optimized with the gold section method,and the surface electrical field is calculated when the charge is in the optimal position.The result shows that the distribution of the surface electrical field and its maximal value can be calculated accurately with this method,although less number of simulation charges is used in this proposed method and the calculation is simple.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61671464,61701523,and 61471389)
文摘A novel approach devoted to achieving ultra-wideband radar cross section reduction(RCSR) of a waveguide slot antenna array(WGSAA) while maintaining its radiation performance is proposed. Three kinds of artificial magnetic conductors(AMCs) tiles consisting of three types of basic units resonant at different frequencies are designed and arranged in a novel quadruple-triangle-type configuration to create a composite planar metasurface. The proposed metasurface is characterized by low radar feature over an ultra-wideband based on the principle of phase cancellation. Both simulated and measured results demonstrate that after the composite metasurface is used to cover part of the antenna array, an ultrawideband RCSR involving in-band and out-of-band is achieved for co-and cross-polarized incident waves based on energy cancellation, while the radiation performance is well retained. The proposed method is simple, low-cost, and easy-tofabricate, providing a new method for ultra-wideband RCSR of an antenna array. Moreover, the method proposed in this paper can easily be applied to other antenna architectures.