The plane wave spectrum surface integration (PWS SI) is a practical and efficient method for antenna radome system analysis, especially for determining the boresight error (BSE) in the system. But it is only used f...The plane wave spectrum surface integration (PWS SI) is a practical and efficient method for antenna radome system analysis, especially for determining the boresight error (BSE) in the system. But it is only used for sum pattern calculation till now, and BSE is calculated by the beam maximum searching method. In this paper, the aperture distribution for difference pattern is formulated as the product of that for sum pattern and a two dimensional periodic window function. A series representation for the spectrum of difference pattern is then obtained according to the convolution theorem. The truncation error of the series has been analyzed by introducing the coverage radius of the spectrum of sum pattern. Based on this representation, the PWS SI technique is extended to difference pattern calculation of radome enclosed antennas. The BSE of a three dimensional multilayered radome, with thickness tapers in all layers, is calculated through the difference pattern null searching. Owing to the steep slope of difference pattern near the nulls, this method for BSE calculation is more stable and reliable than the original beam maximum searching method in PWS SI analysis. The results are compared with those from aperture integration surface integration (AI SI) analysis and the measured ones.展开更多
We studied the system of pure Rashba spin–orbit coupled Bose gas with an in-plane magnetic field. Based on the mean field theory, we obtained the zero temperature phase diagram of the system which exhibits three phas...We studied the system of pure Rashba spin–orbit coupled Bose gas with an in-plane magnetic field. Based on the mean field theory, we obtained the zero temperature phase diagram of the system which exhibits three phases, plane wave（PW） phase, striped wave（SW） phase, and zero momentum（ZM） phase. It was shown that with a growing in-plane field,both SW and ZM phases will eventually turn into the PW phase. Furthermore, we adopted the Bogoliubov theory to study the excitation spectrum as well as the sound speed.展开更多
针对电磁混响室难以仿真的问题,分析了平面波叠加模拟混响室场分布的合理性,根据理想混响室特征给出了叠加平面波的幅值、极化角度等参数设置的细节信息。在此基础上,利用Matlab调用FEKO的混合编程方法进行了场环境模拟,检验结果表明,...针对电磁混响室难以仿真的问题,分析了平面波叠加模拟混响室场分布的合理性,根据理想混响室特征给出了叠加平面波的幅值、极化角度等参数设置的细节信息。在此基础上,利用Matlab调用FEKO的混合编程方法进行了场环境模拟,检验结果表明,叠加场环境特性与混响室场分布特性保持了一致。利用该方法,对某开缝矩形腔体的屏蔽效能进行了仿真测试,并取得了与实测数据相符的结果,其屏蔽效能约为15 d B。该方法有效避免了对混响室的精确建模,大大降低了混响室条件下相关测试仿真的难度与计算量,同时为深入分析混响室场环境特性提供了一条捷径。展开更多
文摘The plane wave spectrum surface integration (PWS SI) is a practical and efficient method for antenna radome system analysis, especially for determining the boresight error (BSE) in the system. But it is only used for sum pattern calculation till now, and BSE is calculated by the beam maximum searching method. In this paper, the aperture distribution for difference pattern is formulated as the product of that for sum pattern and a two dimensional periodic window function. A series representation for the spectrum of difference pattern is then obtained according to the convolution theorem. The truncation error of the series has been analyzed by introducing the coverage radius of the spectrum of sum pattern. Based on this representation, the PWS SI technique is extended to difference pattern calculation of radome enclosed antennas. The BSE of a three dimensional multilayered radome, with thickness tapers in all layers, is calculated through the difference pattern null searching. Owing to the steep slope of difference pattern near the nulls, this method for BSE calculation is more stable and reliable than the original beam maximum searching method in PWS SI analysis. The results are compared with those from aperture integration surface integration (AI SI) analysis and the measured ones.
基金Project supported by the National Natural Science Foundation of China(Grant No.10774088)
文摘We studied the system of pure Rashba spin–orbit coupled Bose gas with an in-plane magnetic field. Based on the mean field theory, we obtained the zero temperature phase diagram of the system which exhibits three phases, plane wave（PW） phase, striped wave（SW） phase, and zero momentum（ZM） phase. It was shown that with a growing in-plane field,both SW and ZM phases will eventually turn into the PW phase. Furthermore, we adopted the Bogoliubov theory to study the excitation spectrum as well as the sound speed.
文摘针对电磁混响室难以仿真的问题,分析了平面波叠加模拟混响室场分布的合理性,根据理想混响室特征给出了叠加平面波的幅值、极化角度等参数设置的细节信息。在此基础上,利用Matlab调用FEKO的混合编程方法进行了场环境模拟,检验结果表明,叠加场环境特性与混响室场分布特性保持了一致。利用该方法,对某开缝矩形腔体的屏蔽效能进行了仿真测试,并取得了与实测数据相符的结果,其屏蔽效能约为15 d B。该方法有效避免了对混响室的精确建模,大大降低了混响室条件下相关测试仿真的难度与计算量,同时为深入分析混响室场环境特性提供了一条捷径。
