三角形对称双脊波导的有限元分析与设计

在对新型三角形对称双脊波导特性参数研究的基础上,应用有限元法系统分析计算了三角形对称双脊波导几何尺寸变化对截止波长、单模带宽、场结构、特性阻抗、衰减常数及功率容量等传输特性的影响.与常规矩形双脊波导相比,三角形对称双脊波导具有小的截止波长、窄的单模带宽、低的功率容量、高的衰减常数和大的特性阻抗,可用于窄带微波滤波器.得...     

组合形变对三角形脊波导传输特性的影响

脊波导的传输特性包括截止波长、单模带宽、衰减常数、功率容量以及特性阻抗。脊波导器件在装配使用中所产生的错位形变与边侧形变很难单独发生,因此,有必要研究错位形变、底部形变、单侧形变、双侧形变结合的组合形变。利用ANSYS建立模型与MATLAB编写有限元程序相结合的方法计算了三角形脊波导组合形变对其传输特性的影响。研究结果表明,组合形变对三角形脊波导的截止波长、单模带宽影响较小,三边形变与错位底部形变对三角形单脊波导功率容量、衰减常数及特性阻抗影响较大,研究结果将为三角形脊波导的应用提供了理论依据。     

填充介质倒梯形脊波导截止特性的有限元分析

为了寻找最佳截止特性的填充介质脊波导结构,提出了填充介质倒梯形对称双脊波导.采用有限元法借助MATLAB软件计算了填充介质倒梯形对称双脊波导在TE模式下的截止特性,即主模截止波长和单模带宽.绘制出主模场结构图,并分析脊波导截止特性与填充介质相对介电常数之间的关系,给出了关系曲线图.这些结果将对填充介质波导的设计和工程应...     

对称梯形脊波导传输特性的FDTD的分析

为了研究正梯形和倒梯形对称双脊波导的传输特性,采用时域有限差分法,计算了窄边与宽边比为0.45的条件下,脊的几何尺寸在中间位置连续变化时的传输特性,得出其TE模式的截止波长、单模带宽,并且给出了上述特性与波导尺寸之间的关系曲线.结果表明脊间距越小,单模带宽越高,倒梯形对称双脊波导的截止波长较同尺寸矩形和梯形要大.所得结果对波导器件的设计有重要参考价值.     

脊波导各种参数的计算

给出脊波导的主要参数：主模截止波长、脊波导单模工作带宽、脊波导特性阻抗、脊波导功率容量、脊波导衰减，及各参数的完备计算方法、部分参数的修正曲线。     

基于有限元法的新型双脊波导传输特性的研究

文章采用有限元法研究了圆形和椭圆形两种变形对称双脊波导对传输特性的影响.计算了脊的尺寸变化时的截止波长和单模带宽,给出了主模场结构图以及变形对截止波长和单模带宽影响的关系曲线,并分析了传输特性随对称脊波导结构尺寸变化的情况.通过这些研究,能够为变形双脊渡导的应用和研究提供有价值的参考.     

有限元法的脊位于窄边的脊波导特征值分析

提出用有限元方法分析位于窄边的脊波导主模的截止波长和场结构图以及单模带宽特性，推导出用有限元法计算相关参数的计算公式。编程计算了双脊、单脊和不对称脊波导的特征值，求解了三种脊位于窄边的脊波导的传输特性，并给出了截止波长和单模带宽曲线以及场结构变化。     

两种变形双脊波导传输特性的分析研究

为了寻找最佳传输特性的对称双脊波导结构,提出了圆形和椭圆形两种变形对称双脊波导,采用有限元的方法,研究了圆形和椭圆形两种变形对称双脊波导对传输特性的影响。计算了脊尺寸变化时的截止波长和单模带宽,给出了主模场结构图以及变形对截止波长和单模带宽影响的相应的关系曲线,并分析了传输特性随对称脊波导结构尺寸的变化情况。该研究结果对变形双脊波导的应用和研究提供了参考,并为脊波导器件的小型化提供了指导。     

形变对三角形脊波导特性的影响

脊波导的功率容量、衰减常数和特性阻抗是其传输特性的重要组成部分。在日常应用中,脊波导元件必然会存在一定的形变。文章应用ANSYS建模与MATLAB软件相结合的方法计算了三角形脊波导错位和受力形变对其功率容量、衰减常数和特性阻抗的影响。结果表明,错位形变对三角形脊波导的衰减常数影响较小,而各项特性参数受底部形变影响较大,研究所得结果可为三角形脊波导广泛应用提供参考。     

变形对矩形单脊波导特性的影响

针对脊波导器件在生产、装配及使用中可能产生的变形,采用有限元法研究了错位变形和受力变形对矩形单脊波导衰减特性、功率容量和阻抗特性的影响。数值分析结果表明:随着脊波导变形程度的增大,衰减常数增大,功率容量和特性阻抗减小,其中下侧受力变形对矩形单脊波导的特性参数影响最大,因此在波导器件的使用过程中应尽量避免下侧受力变形。     

Propagation in Dielectric Slab Loaded Rectangular Waveguide

Propagation in dielectric loaded rectangular waveguide is investigated theoretically for varying slab thickness and dielectric constant. The slabs are placed across the center of the waveguide in the E plane. This geometry is found to offer bandwidths in excess of double that of rectangular waveguide for dielectrics having dielectric constants of approximately 18. Power handling capacities which are double or triple that of standard waveguide are achievable using the dielectric loaded waveguide. In addition to the theory, design curves of bandwidth, guide wavelength, cutoff wavelength, impedance, power handling capacity, wall losses, and dielectric losses are presented and compared to experiment where possible.     

TE Modes of the Dielectric Loaded Trough Line

The properties of TE modes on a dielectric loaded trough waveguide have been investigated. In the case of the dominant mode of this line (TE/sub 20/), families of design curves giving the field distribution, guide wavelength, power handling capability, wall losses, and dielectric losses as a function of operating wavelength, waveguide dimensions and dielectric constant are presented. For a loosely bound wave, the losses are comparable to those of conventional rectangular waveguide and the power handling capability is an order of magnitude greater. The apparatus and procedure used to measure guide wavelength, rate of field decay in the transverse direction, and attenuation are described. The measured performance is in close agreement with the theoretically predicted characteristics.     

脊背型介质加载表面等离子体波导传输特性研究

为降低传输过程中的损耗,加强介质加载等离子体波导的模式场约束,并且优化等离子体波导的传输性能,对基于介质加载的表面等离子体波导的传输特性做了进一步的研究,设计了一种脊背型介质加载等离子体波导,并对其模式场分布及其传输参数随波导中的几何参数与电磁参数的变化关系做了相应的研究。仿真结果得出:基模的电场分量主要分布在该结构的金属/介质层1界面。该模式的传输特性,随着该波导的几何参数的变化而发生相应改变,因而可以通过改变这种结构的几何参数,对场实现有效控制,使其局域性明显增强。     

A Variational Theory for Wave Propagation in Inhomogeneous Dielectric Slab Loaded Waveguides

A novel numerical technique based on the variational formulation defined only in the slab is developed to study the loaded rectangular waveguide with an inhomogeneous dielectric slab. The variational equation for the boundary value problem is formulated and solved numerically, using the finite element method with piecewise quadratic trial functions. A comparison of this new technique with the conventional variational ones is presented. Various propagation characteristics, such as the phase constant, useful bandwidth, power handling capacity, and attenuation constants due to conductor and dielectric losses, are investigated for the waveguide centrally loaded with a slab of parabolic dielectric profile. The effects of changes in dielectric profiles are discussed by examining the results for the slabs with constant and parabolic profiles.     

Waveguide Sandwich Filters

A new class of waveguide filters is introduced, constructed from several thin plates sandwiched together. The combination of alternate plates having large and small rectangular apertures leads to a propagating structure which possesses a bandstop response and prescribed characteristic impedance. This basic element may be used as a simple compact bandstop filter, particularly where the main passband and stopband are well separated, such as in harmonic rejection. For filters with many stopbands, combinations of several waveguide sandwich filter elements are used to provide the main passband and the required attenuation characteristics in the prescribed stopbands. Although the filter is ideally suited for bandstop filtering due to its small size, low cost, low loss, and high power handling capability, additional applications to bandpass filtering and dispersive delay line operation are also cited.     

A High-Power Rotary Waveguide Joint

A conceptually new type of contactless multichannel rotary waveguide joint is described. Power handling capability without pressurization exceeds that of the associated waveguides. Electrical features include elimination of impedance and phase variations with rotation, exceptionally low loss and power leakage. Operation is possible over a 10 per cent frequency band with a maximum VSWR of 1.15. Experimental results on a C-band model are given. Both electrical and mechanical design features are presented for a compactly folded design for operation at multimegawatt peak powers.     

介质环加载喇叭的理论分析

本文对介质环加载边界条件特征方程进行了求解。导出了介质环加载波导与光壁波导连接处的模转换计算公式。并且根据这些公式计算了文献[1]设计的介质环加载喇叭的辐射特性,计算结果非常接近实测结果。     

Coplanar Waveguide: A Surface Strip Transmission Line Suitable for Nonreciprocal Gyromagnetic Device Applications

A coplanar waveguide consists of a strip of thin metallic film on the surface of a dielectric slab with two ground electrodes running adjacent and parallel to the strip. This novel transmission line readily lends itself to nonreciprocal magnetic device applications because of the built-in circularly polarized magnetic vector at the air-dielectric boundary between the conductors. Practical applications of the coplanar waveguide have been experimentally demonstrated by measurements on resonant isolators and differential phase shifters fabricated on low-loss dielectric substrates with high dielectric constants. Calculations have been made for the characteristic impedance, phase velocity, and ripper bound of attenuation of a transmission line whose electrodes are all on one side of a dielectric substrate. These calculations are in good agreement with preliminary experimental results. The coplanar configuration of the transmission system not only permits easy shunt connection of external elements in hybrid integrated circuits, but also adapts well to the fabrication of monolithic integrated systems. Low-loss dielectric substrates with high dielectric constants may be employed to reduce the longitudinal dimension of the integrated circuits because the characteristic impedance of the coplanar waveguide is relatively independent of the substrate thickness; this may be of vital importance for Iow-frequency integrated microwave systems.