Silicon(Si)diffraction microlens arrays are usually used to integrating with infrared focal plane arrays(IRFPAs)to improve their performance.The errors of lithography are unavoidable in the process of the Si diffrac-t...Silicon(Si)diffraction microlens arrays are usually used to integrating with infrared focal plane arrays(IRFPAs)to improve their performance.The errors of lithography are unavoidable in the process of the Si diffrac-tion microlens arrays preparation in the conventional engraving method.It has a serious impact on its performance and subsequent applications.In response to the problem of errors of Si diffraction microlens arrays in the conven-tional method,a novel self-alignment method for high precision Si diffraction microlens arrays preparation is pro-posed.The accuracy of the Si diffractive microlens arrays preparation is determined by the accuracy of the first li-thography mask in the novel self-alignment method.In the subsequent etching,the etched area will be protected by the mask layer and the sacrifice layer or the protective layer.The unprotection area is carved to effectively block the non-etching areas,accurately etch the etching area required,and solve the problem of errors.The high precision Si diffraction microlens arrays are obtained by the novel self-alignment method and the diffraction effi-ciency could reach 92.6%.After integrating with IRFPAs,the average blackbody responsity increased by 8.3%,and the average blackbody detectivity increased by 10.3%.It indicates that the Si diffraction microlens arrays can improve the filling factor and reduce crosstalk of IRFPAs through convergence,thereby improving the perfor-mance of the IRFPAs.The results are of great reference significance for improving their performance through opti-mizing the preparation level of micro nano devices.展开更多
Generally, viscoelastic solid constitutive equation can be written into differential form and integral form. From differential form of constitutive equation the mathematical representation of the state space equation ...Generally, viscoelastic solid constitutive equation can be written into differential form and integral form. From differential form of constitutive equation the mathematical representation of the state space equation can be derived. Due to the state space equation, general constitutive equation can be solved by precise integration method that can be used in many fields with the advantages of highly precision and convenience. For linear viscoelastic solids with crack, the finite elements program of the precise integration method for viscoelastic solid is developed, which appears to be efficient and precise. C-integral is used to be the characterising parameter.展开更多
近年来,随着高频电力电子磁元件不断发展,双有源桥变换器(dual active bridge,DAB)拓扑受到广泛应用。DAB传递功率需要变压器串联较大电感,传统分立磁件方案采用变压器及独立电感串联,功率密度低,而现有磁集成结构存在励磁电感下降、损...近年来,随着高频电力电子磁元件不断发展,双有源桥变换器(dual active bridge,DAB)拓扑受到广泛应用。DAB传递功率需要变压器串联较大电感,传统分立磁件方案采用变压器及独立电感串联,功率密度低,而现有磁集成结构存在励磁电感下降、损耗高等问题。为此,文中研究一种磁芯中柱设置分布式气隙的磁集成结构,建立其励磁电感解析模型,对分立磁件方案、传统磁集成方案与所提结构进行系统比较,并制作样机证明所提结构具有低损耗、小体积等优点;此外,为准确计算该结构漏感并在优化设计中实现漏感精准控制,提出基于双二维法的漏感建模方法。首先,针对所提结构建立主视图和左视图的双二维计算模型,为考虑三维下气隙扩散磁通影响,提出气隙修正系数以改进双二维计算精度;其次,针对影响漏感因素进行系统的参数灵敏度分析,以此进行归一化处理及参数扫描;然后,采用基于蚁群算法的BP神经网络建立漏感计算模型;最后,通过3台样机测试,验证漏感模型的准确性。展开更多
基金Supported by the National Natural Science Foundation of China(NSFC 62105100)the National Key research and development program in the 14th five year plan(2021YFA1200700)。
文摘Silicon(Si)diffraction microlens arrays are usually used to integrating with infrared focal plane arrays(IRFPAs)to improve their performance.The errors of lithography are unavoidable in the process of the Si diffrac-tion microlens arrays preparation in the conventional engraving method.It has a serious impact on its performance and subsequent applications.In response to the problem of errors of Si diffraction microlens arrays in the conven-tional method,a novel self-alignment method for high precision Si diffraction microlens arrays preparation is pro-posed.The accuracy of the Si diffractive microlens arrays preparation is determined by the accuracy of the first li-thography mask in the novel self-alignment method.In the subsequent etching,the etched area will be protected by the mask layer and the sacrifice layer or the protective layer.The unprotection area is carved to effectively block the non-etching areas,accurately etch the etching area required,and solve the problem of errors.The high precision Si diffraction microlens arrays are obtained by the novel self-alignment method and the diffraction effi-ciency could reach 92.6%.After integrating with IRFPAs,the average blackbody responsity increased by 8.3%,and the average blackbody detectivity increased by 10.3%.It indicates that the Si diffraction microlens arrays can improve the filling factor and reduce crosstalk of IRFPAs through convergence,thereby improving the perfor-mance of the IRFPAs.The results are of great reference significance for improving their performance through opti-mizing the preparation level of micro nano devices.
文摘Generally, viscoelastic solid constitutive equation can be written into differential form and integral form. From differential form of constitutive equation the mathematical representation of the state space equation can be derived. Due to the state space equation, general constitutive equation can be solved by precise integration method that can be used in many fields with the advantages of highly precision and convenience. For linear viscoelastic solids with crack, the finite elements program of the precise integration method for viscoelastic solid is developed, which appears to be efficient and precise. C-integral is used to be the characterising parameter.
文摘近年来,随着高频电力电子磁元件不断发展,双有源桥变换器(dual active bridge,DAB)拓扑受到广泛应用。DAB传递功率需要变压器串联较大电感,传统分立磁件方案采用变压器及独立电感串联,功率密度低,而现有磁集成结构存在励磁电感下降、损耗高等问题。为此,文中研究一种磁芯中柱设置分布式气隙的磁集成结构,建立其励磁电感解析模型,对分立磁件方案、传统磁集成方案与所提结构进行系统比较,并制作样机证明所提结构具有低损耗、小体积等优点;此外,为准确计算该结构漏感并在优化设计中实现漏感精准控制,提出基于双二维法的漏感建模方法。首先,针对所提结构建立主视图和左视图的双二维计算模型,为考虑三维下气隙扩散磁通影响,提出气隙修正系数以改进双二维计算精度;其次,针对影响漏感因素进行系统的参数灵敏度分析,以此进行归一化处理及参数扫描;然后,采用基于蚁群算法的BP神经网络建立漏感计算模型;最后,通过3台样机测试,验证漏感模型的准确性。
