多层手征介质填充圆波导的分析

本文利用递推本征函数法分析了多层手征介质填充圆波导的传播特性.文中给出了不同介质层中电磁场的递推关系,推导了N层手征介质填充圆波导色散特性的一般性计算公式.作为示例,文中还给出了对几种结构传播特性的计算结果.     

多手征介质填充圆波导的分析

本文利用递推本征函数法分析了多层手征介质填流圆波导的传播特性。文中给出了不同介质层中电磁场的递推关系，推导了Ｎ层手征介质填充圆波导色散特性的一般笥计算公式。作为示例，文中还给出了对几结构传播特性的计算结果。     

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...     

填充两层介质的矩型波导的色散特性

本文导出了两层介质填充的矩型波导的色散方程的解析表达式,讨论了填充多层介质的矩型波导的色散方程的有趣特点,计算了有效介电常数,对工程应用有参考意义。     

基于矢量有限元的任意介质加载波导通用软件设计

本文旨在实现波导问题的通用软件设计,文章完善了各向异性介质填充波导问题的矢量有限元理论,并计算了有耗、各向异性介质加载的任意结构波导模式传输系数、色散曲线和模式电场分布。在计算色散曲线时,本文结合了模式场图以消除HFSS在色散计算过程中对传输模式的误判。对于开放结构波导,采用各项异性介质的完全匹配层（PML）理论实现无限的问题截断。通过与商业电磁仿真软件的计算结果作比较,验证了算法的精确性。     

ENG-MNG介质组合填充矩形波导的TE模传播特性分析

提出了使用磁单负介质和电单负介质组合填充矩形波导结构,在填充波导内电磁场量纵向场法的基础上,应用边界条件得到了双层单负介质填充波导后传播常数解。研究了在不同的介电常数、磁导率和模式下,传播常数、频率和填充介质厚度之间的关系,提出按照一定比例关系和介质参数填充后的波导的带通传播特性。     

非均匀介质填充波导法传输特性的数值模式匹配分析法

用数值模式匹配理论研究了非均匀介质填充波导混合模问题的全波分析方法．给出了波导中的统一色散方程和完整的电磁场表达式，以部分介质填充波导为例进行了计算，所得结果与文献报道相吻合．     

基于时域有限差分法填充介质梯形脊波导研究

为了研究填充介质对脊波导截止特性的影响,文章采用FDTD(时域有限差分)法计算了填充介质梯形双脊波导在TE(横电波)模式下的截止特性随几何尺寸的变化,并给出了关系曲线。结果表明,脊间距越小,填充介质的相对介电常数越大,截止波长越长,单模带宽越窄。研究结果丰富了现存填充介质波导数据,有助于填充介质波导的设计和工程应用。     

电磁场与微波技术

044,TN814.5 94010864多层手征介质填充圆波导的分析/沈忠祥(南京航空学院)11电子科学学刊一1993,15(5)一546~550 利用递推本征函数法分析了多层手征介质填充回波导的传播特性.给出了不同介质层中电磁场的递推关系,推导了N层手征介质填充回波导色散特性的一般计算公式.作为示例,还给出了对几种结构传播特性的计算结果.图5参8(文)044 94010865UA加速间隙内横向场分析及对发射度的影响/章冠人(西南流体物理所)//强激光与粒子束一1993,5(2)一191~197 加速间隙是LIA漂移管中间突出的圆柱形空隙.在这空隙构成的空腔内,存在两种电磁场,一种为…     

填充多层介质的共焦椭圆同轴线传播特性

采用在椭圆柱坐标系中分离变量的方法,得到了填充多层介质共焦椭圆同轴线模式特征方程.研究表明:当椭圆退化为圆时,利用角向和径向马修函数的渐进关系,可得到填充多层介质的圆形同轴线的模式特征方程,由此可见,圆形同轴线可看作椭圆形同轴线的特例;当椭圆同轴线内导体半长轴大小为零时,则椭圆同轴线就变成椭圆波导,同样的方法,可得到填充多层介质的椭圆波导模式特征方程.当填充一层介质时,得到了椭圆同轴线和椭圆波导的模式特征方程,结果和相关文献所得结果相同.作为示例,对填充一层介质和两层介质的椭圆同轴线中一些模式色散特性进行了数值计算,分析了椭圆同轴线中介质参数的变化以及椭圆同轴结构的变化等对其传播特性的影响.     

Attenuation characteristics of a circular chirowaveguide

The attenuation constant of a circular waveguide completely filled with a homogeneous, isotropic and lossless chiral medium is calculated after first solving the wave equation and determining the field components. The waveguide supports only the hybrid modes and the first modes with azimuthal indices of 0 and 1 are studied.<>     

Propagation of TM modes in a circular dielectric waveguide filled with a medium with Kerr nonlinearity

Eigenmodes propagating in a cylindrical dielectric waveguide of circular cross section filled with a nonlinear medium whose nonlinearity is described by the Kerr law are analyzed. The nonlinear eigenvalue boundary problem for the nonlinear Helmholtz equation is considered. An iterative numerical method for obtaining the approximate solutions is developed. Numerical results are presented.     

Characteristics of TE-modes in rectangular waveguides containing dielectric layers

The eigenequation of TE-modes in rectangular waveguides filled with arbitrary layer dielectrics is presented. As an example, we calculate the characteristics of a rectangular waveguide which is devided three regions by dielectrics. Using a Personal Computer the results can be got in several minutes, and the results agree with that of other authors very well. Some curves are given.     

Propagation characteristics of a circular waveguide filled with a chiroferrite medium

A chiroferrite is made from chiral objects immersed in a magnetically biased ferrite. A waveguide including a chiroferrite is anticipated to possess some novel features due to the presence of chirality in combination with anisotropy. In this paper, the propagation characteristics of a circular metal waveguide filled with a chiroferrite medium are investigated by an analytical procedure. The equations of relations between the transverse components and the longitudinal ones of electromagnetic fields in general chiroferrite waveguides are derived in a cylindrical coordinate system. The coupled wave equations for the longitudinal electric and magnetic fields are decoupled into two Helmholtz equations which are then solved analytically. The characteristic equation is formulated for the circular chiroferrite waveguide. Propagation constants varying with the structural and material parameters have been calculated for several lower chiral modes. A number of interesting features have been revealed by the numerical results.     

On Guided Waves in Moving Anisotropic Media

Based upon the Maxwell-Minkowski theory, the equations governing the propagation of electromagnetic waves in a cylindrical waveguide of an arbitrary cross section filled with a moving anisotropic medium are derived. The governing equations are reducible to a pair of coupled wave equations in the axial components of the electric and magnetic fields, which in turn can be solved through the solution of a single second order scalar homogeneous Hehnholtz equation. For a general anisotropic medium no pure TM or TE modes can exist in the waveguide. However, if the moving medium is uniaxially anisotropic, TM and TE modes are possible. It is interesting to note that the cutoff frequencies are always lowered by a factor which depends upon the velocity of the medium and is independent of the guide geometry. The formulas for the characteristic wave impedance and power flow in a waveguide for a moving uniaxial medium, if expressed in terms of the new cutoff frequency, have the same forms as those for a moving isotropic medium. The propagation characteristics of waveguides of rectangular and circular cross sections filled with a moving uniaxial gyroelectric medium are discussed.     

The electric quadrupole contribution to the circular birefringenceof nonmagnetic anisotropic chiral media: a circular waveguide experiment

Constitutive relations which include electric quadrupole terms, in addition to electric and magnetic dipole terms, are used to describe the “optical activity”, in particular the circular birefringence, of an anisotropic chiral medium which is nonmagnetic. The resulting permittivity and chirality tensors are then used to predict the rotation of the polarization plane of a linearly polarized wave propagating in a circular waveguide filled with the medium. The numerical predictions were tested by measurements between 2.4 and 4 GHz on a 2 m long artificial crystal in a circular waveguide and it was found that the rotation of the polarization was within 13% of the predicted value-good agreement after considering the possible sources of error. It is thus established that the effect of electric quadrupoles must be included when modeling the optical activity of anisotropic chiral media in the long wavelength regime. The anisotropic chiral media which are dealt with here can be classified according to the crystallographic point groups to which they belong, and they may therefore also be considered to be artificial crystals     

Analysis of Circular Chiral Dielectric Waveguides

The general eigenequations and the field expressions for circular waveguides containing chiral material in both the core and the cladding are given in a simple formulation. The results indicate that there are two types of field distribution which is related to the operating wavelength and chiral admittance. When the chiral admittance is larger than a critical value, the fields of one kind of circularly polarized wave in the core become exponentially-like damping in the transverse direction. Based on the eigenequations, the characteristics of a circular waveguide with chiral medium filled in the core are investigated. The relation between the cutoff frequency and the chiral admittance, the dispersion curves for some modes with different angular mode number and the transverse distribution of fields are presented. Some features different from the ordinary circular waveguide are resulted.     

Analysis of Circular Dielectric Waveguide with Chiral Cladding

The propagation characteristics of a circular dielectric waveguide with chiral media filled in the cladding are investigated. The relation between the cutoff frequency and the chiral admittance, the dispersion curves for some modes with different angular mode numbers and the transverse distribution of fields are presented. Some new features different from the ordinary circular dielectric waveguide are resulted. The results show that the cladding chirality may lead to a single-mode operation in the circular dielectric waveguide.