微屏蔽传输线的分析与计算

微屏蔽线（ＭＳＬ）是一种新型的平面传输线，其超高的频率响应和极低的色散特性，可望广泛地应用于各种毫米波电路中，本文把用于鳍线、微带线的谱域导抗法推广到这种半封闭的传输线中，分析、计算了两种微屏蔽传输线的色散特性。计算结果与有关的实验相吻合，为这种半封闭的新型毫米波传输线提供了一种有效的计算方法。     

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.     

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。     

矩形变形脊波导主模截止波长的计算

为了满足微波传输系统性能的某些需求,各种结构形状的新型波导应运而生.采用有限差分法,利用Matlab计算了变形矩形脊波导在改变波导内部脊的位置、形状和大小等不同情况下的波导主模截止波长,并对计算结果进行了对比分析,得出了主模截止波长随着内脊的高度、宽度、上下脊高度及宽度比例的变化而变化的一些相关结论.     

矩形变形脊波导主模截止波长和特性阻抗计算

从矩形波导主模场分布的特征出发，用横向谐振法推导出各种矩形变形脊波导主模的截止波长和特性阻抗的计算公式，然后结合具体模型，通过实验验证，证明了这些计算公式的实用性，可用于工程设计计算。     

多模光纤光栅反射谱特性的研究

在本文中，通过引入主模和独立模光栅的概念，对梯度多模光纤光栅进行了数值模拟，计算了反射率谱线图，并就介电常数微拢、光栅长度以及工作波长等参数的变化对光栅反射率谱图的影响进行了详细讨论。计算谱图和实验谱的比较表明两者基本一致。     

基干微屏蔽线的140GHz低通滤波器研究

微屏蔽传输线是一种采用薄膜支撑的传输线结构,具有损耗小、阻抗可变范围大的特点。利用保角变换的方法对微屏蔽线单位长度的电容进行了分析,给出了单位电容值与相对介电常数、特征阻抗的关系。利用阶跃阻抗的结构,设计一个5阶的带内波纹为0.5dB、截止频率为140Gz的切比雪夫低通滤波器,并用HFSS仿真分析其传输特性,在滤波器的末端串联短接式短截线结构增强其带外抑制作用。     

基于微屏蔽线的140GHz低通滤波器研究

微屏蔽传输线是一种采用薄膜支撑的传输线结构,具有损耗小、阻抗可变范周大的特点。利用保角变换的方法对微屏蔽线单位长度的电容进行了分析,给出了单位电容值与相对介电常数、特征阻抗的关系。利用阶跃阻抗的结构．设计一个5阶的带内波纹为0．5dB、截止频率为140CHz的切比雪夫低通滤波器,并用HFSS仿真分析其传输特性,在滤波器的末端串联短接式短截线结构增强其带外抑制作用。     

基于有限元法分析设计双奇异脊波导

本文应用电磁场有限元法分析了双奇异脊波导的传输特性,编程分析计算了不同横截面的双奇异脊波导的主模工作带宽。并比较了脊的尺寸和间距不同时,其主模截止波长和单模带宽的变化规律,得到了相应的数值解。讨论了网格划分对计算结果的精确度的影响。为双奇异脊波导的设计和研究提供了参考。     

脊位于窄边的四种加载介质波导传输特性的有限元计算

运用矢量有限元方法对脊位于窄边的四种加载介质双脊波导的主模截止波长和单模带宽特性进行了计算和分析,四种波导分别为脊位于窄边的加载介质双脊矩形波导、加载介质双脊梯形波导、加载介质双脊V形波导以及加载介质双脊椭圆形波导。计算结果表明,脊位于窄边的四种加载介质双脊波导的两种传输特性总体相似,和脊位于宽边相比,脊位于窄边的主模归一化截止波长和单模带宽总体小很多,且脊位于宽边时的特性变化趋势比脊位于窄边时剧烈。这些计算结果将有助于微波器件及微波系统的设计。     

Analytical analyses of v, elliptic, and circular-shaped microshieldtransmission lines

Several new types of monolithic coplanar transmission lines, v, elliptic, and circular-shaped microshield coplanar waveguide, have been proposed. The characteristic impedance expressions for those transmission lines have been derived using the conformal mapping method (CMM) under the assumption of the pure-TEM propagation and zero dispersion. In the analyses of the elliptic and the circular-shaped microshield coplanar lines, the methods using the graphical approximation and taking the geometric mean value of the upper and the lower bounds to the size of the line are put forward to calculate the characteristic impedance of this two kinds of microshield coplanar lines. The numerical results show the effects of the different shaped microshield walls on characteristic impedances     

梯形屏蔽共面波导及共面耦合线特性阻抗的计算

提出了适用于ＭＭＩＣ设计一类新型共面传输线，它包括梯形屏蔽共面波导（ＳＭＣＰＷ）梯形屏蔽共面耦合线（ＳＭＣＣＬ）共面耦全梯形屏蔽线（ＣＣＳＭＬ）推导出用于计算这些传输线的ＴＥＭ参数的解析公式，数值计算结果显示了此类共面传输线的性质。     

On the Cutoff Wavelength of Rectangular-Shaped Microshield Line by Edge Element Method

In this paper, the cutoff characteristic of rectangular-shaped microshield transmission line has been analysed by edge element method. Dependence of cutoff wavelengths on the thickness of metallic signal strip, dielectric constant of dielectric substrate and the width of the rectangular-shaped ground conductor are presented in tabular form. Numerical results in this paper have important values in design of rectangular-shaped microshield lines in microwave and millimeter wave integrated circuits.     

High performance microshield line components

Several millimeter-wave passive components have been fabricated using the microshield transmission line geometry, and their performance is presented herein. Microshield is a quasi-planar, half-shielded design which uses a thin dielectric membrane (1.5 μm) to support the conducting lines. This approach provides a nearly homogeneous, air-filled environment and thus allows extremely broad-band TEM operation. This paper examines the conductor loss and effective dielectric constant of microshield lines and presents results on transitions to conventional coplanar waveguide, right-angle bends, different stub configurations, and lowpass and bandpass filters. Experimental data is provided along with numerical results derived from an integral equation method. The microshield line is shown to be very suitable for high performance millimeter and submillimeter-wave applications     

Network analyses for transmission characteristics of several kinds of curve-shaped groove waveguides

In this paper, the several kinds of the novel curve-shaped groove guides including the whole elliptic-, whole cosine- and hyperbolic-groove guides as the new millimeter wave transmission lines are presented. The dispersion, cut-off and band characteristics of the dominant mode for the several kinds of the curve-shaped groove guides are analysed by using the equivalent network method with transverse resonance. The obtained results have important values in their theoretical studies and actual applications of the curve-shaped groove waveguides.     

Air-Cavity Transmission Lines on Anodized Aluminum for High-Performance RF Modules

In this study, we form air-cavity transmission lines on anodized aluminum substrates. The fabricated transmission lines are microstrip, grounded CPW, and microshield structures. Thick anodized alumina is used as the post of the suspending structures, and it is realized very easily using selective chemical wet-etching. The insertion losses of the fabricated transmission lines on the anodized aluminum are within a range of 0.2-0.26 dB/mm, and they improve greatly after realizing air-cavity structures to 0.043-0.076 dB/mm at 40 GHz.     

Transmission characteristics of several kinds of closed groove waveguides for millimeter waves

An advantage of closed groove guide over open groove guide is attended. In this paper, the several kinds of closed groove guides including the trapezoidal-, elliptic- and parabolic-groove guides as new types of millimeter wave transmission lines are presented. Their dispersion and cut-off characteristics of the dominant mode are analysed and compared with ones of the closed V-and circular- groove guides by using the equivalent network method. The obtained results have important meaning in theoretical studies and actual applications of groove waveguides.     

微屏蔽三线对称结构带通滤波器设计

对薄膜支撑空腔型微屏蔽传输线进行分析,提出微屏蔽传输线的物理结构。为了验证微屏蔽传输线在毫米波应用的优势,利用类比平行耦合微带线滤波器的方法设计了一种4阶切比雪夫三线对称结构微屏蔽线滤波器。通过对该微屏蔽腔体结构进行HFSS仿真,得到中心频率35 GHz的宽带滤波器,带宽15 GHz,带内插损小于0.5 dB,带外抑制>40 dB@53 GHz,器件尺寸8.24 mm×1.5 mm×0.65 mm。该设计为基于平面传输线的滤波器在毫米波频段的实现提供了一种可行的方法。