This article presents advancements in an analytical mode-matching technique for studying electromagnetic wave propagation in a parallel-plate metallic rectangular waveguide.This technique involves projecting the solut...This article presents advancements in an analytical mode-matching technique for studying electromagnetic wave propagation in a parallel-plate metallic rectangular waveguide.This technique involves projecting the solution onto basis functions and solving linear algebraic systems to determine scattering amplitudes.The accuracy of this method is validated via numerical assessments,which involve the reconstruction of matching conditions and conservation laws.The study highlights the impact of geometric and material variations on reflection and transmission phenomena in the waveguide.展开更多
A solution of the scattering problem of guided SH_wave by apartly debonded circular cylinder centered in a traction free plate has been set up. The plate is divided up into three regions with two imaginary planes perp...A solution of the scattering problem of guided SH_wave by apartly debonded circular cylinder centered in a traction free plate has been set up. The plate is divided up into three regions with two imaginary planes perpendicular to the plate walls. In the central region where the partly debonded cylindrical obstacle is posted, the wave field is expanded into the cylindrical wave modes and Chebyshev polynomials. In the other two exterior regions the fields are expanded into the plate wave modes. A system of fundamental equations to solve the problem is obtained according to the traction free boundary condition on the plate walls and the continuity condition of the traction and the displacement across the imaginary planes. The approximate numerical method termed mode_matching technique is used to construct a matrix equation to obtain curves showing the coefficient of reflection and transmission versus the ratio of the cylinder's radius to the plate's half_thickness and the angular width of the debonded region. A comparison of the numerical results between the welded interface condition and the debonded interface condition is made, and the results are discussed.展开更多
提出了一种基于模式匹配法的窄带Iris波导滤波器设计方法,通过引入Matlab优化使滤波器设计周期缩短了约1/3。设计的窄带滤波器相对带宽小于3%,且较好的克服了毫米波频段滤波器高频端带外抑制较差的难题。测试结果表明,该带通滤波器插入...提出了一种基于模式匹配法的窄带Iris波导滤波器设计方法,通过引入Matlab优化使滤波器设计周期缩短了约1/3。设计的窄带滤波器相对带宽小于3%,且较好的克服了毫米波频段滤波器高频端带外抑制较差的难题。测试结果表明,该带通滤波器插入损耗小于0.8 d B,驻波比小于1.2,中心频率34.86 GHz,带外抑制52 d B@36.5 GHz,已被成功应用于某毫米波雷达通信系统中。展开更多
目前1.5μmLD泵浦铒玻璃被动调Q微型激光器是军事激光测距的研究热点,获得较高的激光重复频率和单脉冲能量尤为重要。文中主要报道了一种应用于激光测距领域的铒镱共掺磷酸盐玻璃被动调Q微片激光器。激光器采用中心波长为940 nm的单管...目前1.5μmLD泵浦铒玻璃被动调Q微型激光器是军事激光测距的研究热点,获得较高的激光重复频率和单脉冲能量尤为重要。文中主要报道了一种应用于激光测距领域的铒镱共掺磷酸盐玻璃被动调Q微片激光器。激光器采用中心波长为940 nm的单管二极管为泵浦源,铒镱共掺磷酸盐玻璃(Er^(3+),Yb^(3+):glass)作为增益介质,CO_^(2+):MgAl_2O_4(CO:MALO)作为可饱和吸收体。通过分析泵浦光斑半径对模式匹配影响,优化泵浦光斑半径,实验分析可饱和吸收体初始透过率T0和输出镜反射率R对输出激光参数影响,优化T0和R值。最终实验中采用增益预泵浦方式,实现重频1 k Hz,单脉冲能量40μJ,脉宽5.09 ns,峰值功率7.85 k W,光束质量M2=1.4,波长1 535 nm的稳定激光输出。展开更多
The E-plane waveguide branch directional couplers are analyzed by a method which combines the multimode network theory with rigorous mode-matching approach. The electromagnetic field components are expanded by the sup...The E-plane waveguide branch directional couplers are analyzed by a method which combines the multimode network theory with rigorous mode-matching approach. The electromagnetic field components are expanded by the superposition of LSEx modes rather than TE and TM modes in the mode-matching procedure. Meanwhile, the electromagnetic problem is transferred into the network problem through the mode-matching treatment. It is shown that the present method has the advantages of simplicity and less computation without affecting the accuracy of the calculation.展开更多
A systematic algorithm is set up with vertical numerical mode-matching method to findthe Green’s function of static-steady field in the 2-D axial symmetric inhomogeneous me-dia. The formultion is given totally in mat...A systematic algorithm is set up with vertical numerical mode-matching method to findthe Green’s function of static-steady field in the 2-D axial symmetric inhomogeneous me-dia. The formultion is given totally in matrix forms, which could be treated easily withmicrocomputers. Furthermore, no numerical integration is needed throughout thesimulation process. The efficiency of the algorithIn can be about 100 times higher that ofthe 2-D finite element method. The vertical numerical mode-matching tecgnique is pro-展开更多
From the mode-marching method,by doing some transforms and derivations,the scatteringand propagation integral equations for solving the problems of discontinuous dielectric structure are ob-tained.The necessary and su...From the mode-marching method,by doing some transforms and derivations,the scatteringand propagation integral equations for solving the problems of discontinuous dielectric structure are ob-tained.The necessary and sufficient condition for the existence of solution of propagating equations is giv-en.It is really the dispersion equation of the dielectric structure.As an example,a succinct solution ofone-step discontinuous dielectric structure is derived.展开更多
文摘This article presents advancements in an analytical mode-matching technique for studying electromagnetic wave propagation in a parallel-plate metallic rectangular waveguide.This technique involves projecting the solution onto basis functions and solving linear algebraic systems to determine scattering amplitudes.The accuracy of this method is validated via numerical assessments,which involve the reconstruction of matching conditions and conservation laws.The study highlights the impact of geometric and material variations on reflection and transmission phenomena in the waveguide.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 19774065) .
文摘A solution of the scattering problem of guided SH_wave by apartly debonded circular cylinder centered in a traction free plate has been set up. The plate is divided up into three regions with two imaginary planes perpendicular to the plate walls. In the central region where the partly debonded cylindrical obstacle is posted, the wave field is expanded into the cylindrical wave modes and Chebyshev polynomials. In the other two exterior regions the fields are expanded into the plate wave modes. A system of fundamental equations to solve the problem is obtained according to the traction free boundary condition on the plate walls and the continuity condition of the traction and the displacement across the imaginary planes. The approximate numerical method termed mode_matching technique is used to construct a matrix equation to obtain curves showing the coefficient of reflection and transmission versus the ratio of the cylinder's radius to the plate's half_thickness and the angular width of the debonded region. A comparison of the numerical results between the welded interface condition and the debonded interface condition is made, and the results are discussed.
文摘提出了一种基于模式匹配法的窄带Iris波导滤波器设计方法,通过引入Matlab优化使滤波器设计周期缩短了约1/3。设计的窄带滤波器相对带宽小于3%,且较好的克服了毫米波频段滤波器高频端带外抑制较差的难题。测试结果表明,该带通滤波器插入损耗小于0.8 d B,驻波比小于1.2,中心频率34.86 GHz,带外抑制52 d B@36.5 GHz,已被成功应用于某毫米波雷达通信系统中。
文摘目前1.5μmLD泵浦铒玻璃被动调Q微型激光器是军事激光测距的研究热点,获得较高的激光重复频率和单脉冲能量尤为重要。文中主要报道了一种应用于激光测距领域的铒镱共掺磷酸盐玻璃被动调Q微片激光器。激光器采用中心波长为940 nm的单管二极管为泵浦源,铒镱共掺磷酸盐玻璃(Er^(3+),Yb^(3+):glass)作为增益介质,CO_^(2+):MgAl_2O_4(CO:MALO)作为可饱和吸收体。通过分析泵浦光斑半径对模式匹配影响,优化泵浦光斑半径,实验分析可饱和吸收体初始透过率T0和输出镜反射率R对输出激光参数影响,优化T0和R值。最终实验中采用增益预泵浦方式,实现重频1 k Hz,单脉冲能量40μJ,脉宽5.09 ns,峰值功率7.85 k W,光束质量M2=1.4,波长1 535 nm的稳定激光输出。
文摘The E-plane waveguide branch directional couplers are analyzed by a method which combines the multimode network theory with rigorous mode-matching approach. The electromagnetic field components are expanded by the superposition of LSEx modes rather than TE and TM modes in the mode-matching procedure. Meanwhile, the electromagnetic problem is transferred into the network problem through the mode-matching treatment. It is shown that the present method has the advantages of simplicity and less computation without affecting the accuracy of the calculation.
基金Project supported by the National Natural Science Foundation of China.
文摘A systematic algorithm is set up with vertical numerical mode-matching method to findthe Green’s function of static-steady field in the 2-D axial symmetric inhomogeneous me-dia. The formultion is given totally in matrix forms, which could be treated easily withmicrocomputers. Furthermore, no numerical integration is needed throughout thesimulation process. The efficiency of the algorithIn can be about 100 times higher that ofthe 2-D finite element method. The vertical numerical mode-matching tecgnique is pro-
文摘From the mode-marching method,by doing some transforms and derivations,the scatteringand propagation integral equations for solving the problems of discontinuous dielectric structure are ob-tained.The necessary and sufficient condition for the existence of solution of propagating equations is giv-en.It is really the dispersion equation of the dielectric structure.As an example,a succinct solution ofone-step discontinuous dielectric structure is derived.
