手征等离子体波导理论

本文给出了手征等离子体波导（由在柱形波导中填充手征等离体材料构成）中横向场量与纵向场量之间的关系式，并给出了纵向场量的求解公式，作为示例，文中具体研究了平行板手征等离子体波导，得出了其中几个低次传播模式的色散特性曲线。     

手征等离子本填充圆波导的传播特性

本文在柱坐标系中导出了手征等离子体波导内横向场量与纵向场量之间的关系，给出从向场量的波动方程，利用波导壁上的电场边界条件，建立了手征等离子体介质填充的圆波导传播常数的特征方程，计算得到了几种低次模式的传播常数随归一化波导半径及材料参数的一系列变化曲线，分析得出了若干有意义的结论。     

手征等离子体填充圆波导的传播特性

本文在柱坐标系中导出了手征等离子体波导内横向场量与纵向场量之间的关系,给出求解纵向场量的波动方程.利用波导壁上的电场边界条件,建立了手征等离子体介质填充的圆波导传播常数的特征方程,计算得到了几种低次模式的传播常数随归一化波导半径及材料参数的一系列变化曲线,分析得出了若干有意义的结论.     

手征等离子体波导电磁波传输特性

本文把电磁场分解成横向和纵向分量，导出了简明的普适性手征等离子体填充任意截面柱形波导的波动方程和横向纵向场量的关系式，导出了部分填充手征等离子体波导的色散方程。据此调查其电磁波的传播特性。     

手征等离子体波导导波控制特性的研究

应用纵向分量法推导出了完全填充手征等离子体金属圆波导的色散方程。通过数值求解完全填充手征等离子体金属圆波导的色散方程,得出了在不同条件下的几个低阶模的模式色散图。由此分析讨论了手征等离子体金属圆波导的基本传播特性并着重分析了手征导纳和外偏置磁场对完全填充手征等离子体金属圆波导的导波特性的影响并获得了有意义的结果。     

平板状双轴旋电磁手征波导中的耦合模理论

本文严格分析了一种新型双轴旋电磁手征波导中耦合模的传输特性。首先，给出了这种双各向异性手征波导中各横向场分量的纵向场分量表示式，由此得到了纵向场分量的耦合模方程，以及平板状双轴旋电磁手征波导中的色散方程。用数值方法研究了它的色散和截止特性，特别考察了双各向异性和手征性引起的波模分裂，转换效应。     

椭圆手征波导的导模特性研究

该文首先对椭圆手征波导进行了解析求解,导出了模式场解及模式特征方程,然后用数值计算的方法研究了手征参数对椭圆手征波导中导模的色散曲线和截止波长的影响,发现在椭圆手征波导中导模的第一个模式会随手征参数的增加而不同。     

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。     

手征负折射平行板波导中模式的新特性

从理论上研究了手征负折射平行板波导中的导模特性,给出了几个低阶导模的色散关系曲线和场分布、功率流分布.发现了一些新的特性:当手征参数较大发生负折射时基模缺失且色散曲线发生下凹;截止频率不再是传统定义中的纵向传播常数为零时所对应的频率,而是导模可以传播的最小频率;波导中存在后向波,总的功率流与波矢方向相反.     

Mode orthogonality relations and field structure in chirowaveguides

By analyzing the vector and scalar equations for chirowaveguides, two forms of mode orthogonality relations are obtained: the vector formulated orthogonality and the scalar formulated orthogonality. The first one is applicable to the general case of open chiroplasma or chiroferrite waveguides. It is shown that for two parallel-plate isotropic chirowaveguides, these two forms of orthogonality relations differ. Based on mode orthogonality relations, it is shown that in chirowaveguides the polarization of so-called complex modes differs from that of propagating or evanescent modes. The correlation between field components of two complex modes that transfer active power flow in chirowaveguides is obtained     

Excitation of middle-IR range hollow metallic waveguides

The results of the efficiency of low-mode excitation of a parallel-plate hollow metallic waveguides (HMW) as a function of beam and waveguide parameters are represented. Coupling of two waveguides is also discussed.     

Utilization of Anisotropic Metamaterial Layers in Waveguide Miniaturization and Transitions

We introduce a new approach which enables a waveguide to support propagation of electromagnetic waves below the cutoff frequency, as well as which avoids undesirable reflections in a waveguide. These are achieved through the usage of an anisotropic metamaterial layer by employing the concept of coordinate transformation. The proposed method can be utilized for the fabrication of miniaturized waveguides, and for the elimination of discontinuities in abrupt waveguide transitions. We demonstrate some numerical experiments for finite element simulations of parallel-plate and dielectric slab waveguides.     

Coupling Between Two Collinear Parallel-Plate Waveguides of Unequal Widths

The problem of coupling between two collinear parallel-plate waveguides of unequal widths is investigated using the moment methods. The exciting mode of the waveguide is assumed as the incident field and an integral equation for the induced currents is expressed in terms of the reflected, the transmitted, and the evanescent currents on the walls of the waveguides. This integral equation is solved numerically and the results for the reflections and the transmission coefficients and the radiated field are obtained. The effect of varying the coupled waveguide width and the separation distance of the waveguides is investigated.     

Long-term study of 435 MHz radio-frequency radiation on blood-borne end points in cannulated rats. Part I: Engineering considerations

To study the effects of exposure to long-term, low-level radio-frequency radiation (RFR) on various physiological systems in a large population of rodents, a complete exposure facility was designed and constructed at the Georgia Institute of Technology. The major components of the facility included a set of circular, stacked, parallel-plate waveguides fed by slotted-cylinder antennas. The waveguides provided a TE10 mode, horizontally polarized field in which the maximal power density occurred midway between the parallel plates. The feed antenna and the parallel-plate waveguides generated a field that radiated outward and was uniform in the azimuthal plane. Thus, animals arrayed along the periphery of the plates were exposed to a uniform 1.0 mW/cm2 field (1.0 microsecond pulse width, 1 kHz pulse repetition rate, 435 MHz carrier). The facility transmitter provided four channels of 435 MHz RFR at 200 W average (continuous wave) or 5 kW peak (pulsed-wave) power; in addition, the transmitter outputs could be combined into a single channel capable of energizing one tier of the stacked parallel-plate waveguide system at 800 W continuous wave or at 16 kW of pulsed waves. To individually house the 200 rodents involved in the study, both biological and engineering criteria were examined and used to design and construct special Plexiglas cages.     

The theory of chirowaveguides

The theory of chirowaveguides is discussed, and their salient features are analyzed. It is shown that the Helmholtz equations for the longitudinal components of electric and magnetic fields in chirowaveguides are always coupled and that, consequently, in these waveguides individual transverse electric (TE), transverse magnetic (TM), or transverse electromagnetic (TEM) modes cannot be supported. As an illustrative example, the parallel-plate chirowaveguide is analyzed in detail and the corresponding dispersion relations, cutoff frequencies, and propagating and evanescent modes are obtained. In the dispersion (Brillouin) diagram for a chirowaveguide, three regions are identified: the fast-fast-wave region, the fast-slow-wave region and the slow-slow-wave region. For each of these regions, the electromagnetic field components in a parallel-plate chirowaveguide are analyzed and the electric field components are plotted. Potential applications of chirowaveguides in integrated optical devices, communications systems, and printed circuit antennas are mentioned     

Numerical Solution of Coupling Between Two Collinear Parallel-Plate Waveguides

The problem of coupling between two collinear parallel-plate waveguides is investigated numerically using moment methods. The exciting mode in the waveguide is assumed as the incident field, and the integral equation for the induced current is expressed in terms of the reflected, transmitted, and evanescent currents on the waveguides. The integral equation is then solved numerically by a point-matching method and the reflection and the transmission coefficients and the radiated fields are obtained. To examine the accuracy of the results, the special case of a semi-infinite exciting waveguide coupled to a finite coupled waveguide is also considered and is solved numerically by treating the singularities of the induced currents using a transformation method. For a TE/sub 0,1/ excitation of the exciting waveguide, the results of both numerical methods are compared with the analytical results obtained previously using the Wiener-Hopf technique, and are found to be in good agreement. The methods are then used to study the effect of the coupled waveguide on the radiation field.     

Sidelobe suppression in 76-GHz post-wall waveguide-fedparallel-plate slot arrays

Sidelobe suppression is demonstrated for 76-GHz post-wall waveguide fed parallel-plate slot arrays for car radar applications. Taylor distribution illumination control is successfully confirmed experimentally in the slot array on the parallel-plate waveguide. The amplitude distribution in the transverse direction is controlled by shaping a quasi-TEM mode and that in the longitudinal direction is realized by the slot coupling control, both in an oversized waveguide. Measured sidelobes are below -22 dB for one-dimensional (1-D) Taylor tapering while those for two-dimensional (2-D) Taylor distribution are below -18 dB. The gain reduction in comparison with that for uniform illumination is less than 1 dB both in the experiment. All these verify the potential of aperture illumination control of the parallel-plate slot arrays     

Modal analysis of step discontinuities in graded-index dielectricslab waveguides

The modal solutions of the TE- and TM-modes of an arbitrary graded-index dielectric slab waveguide have been derived by applying the generalized telegraphist's equations to the equivalent inhomogeneous parallel-plate waveguide model with electric or magnetic walls. These modal solutions have been employed in a mode-matching procedure to calculate the transmission properties of step discontinuities in arbitrarily graded-index dielectric slab waveguides such as diffused optical waveguides having exponential, Gaussian and complementary error-function index profiles. For slab waveguides containing an abrupt offset, the radiated power is found to increase smoothly with increasing displacement. Power loss calculations for an abrupt change in diffusion depth for which the dominant mode is in the vicinity of cutoff, exhibit a sharp transition from almost zero loss to nearly total radiation loss