非对称宽边耦合CPW微波滤波器的散射参数设计

非对称支持宽边耦合共面波导可看作是非均匀介质中的非对称耦合传输线 ,文中在非均匀介质中的非对称耦合传输线散射参数的基础上 ,推导出非对称宽边耦合共面波导的散射参数。利用所得散射参数研制了非对称支持宽边耦合共面波导滤波器 ,试验结果表明采用散射参数进行电路分析和设计的有效性。设计研制了f =3～ 5GH z的带阻滤波器 ,采用微波复合介质板 (εr=9.6、厚度为 0 .8m m) ,底层填充介质为聚四氟乙烯材料(εr=2 .1) ,上层为空气 ,上、下宽边耦合共面波导的中心导带宽度为 w =3mm ,槽宽为 sg=0 .50 mm ,长为 1=12 .57mm。上、下共面波导距离屏蔽盒顶、底的高度为 h1=10 mm。引出线采用微带渐变线进行阻抗匹配。这些为非对称支持宽边耦合共面波导在三维 (多层 )微波集成电路中的应用奠定了基础     

宽边侧边耦合四微带传输线的频率特性

本文用谱域阻纳分析法研究了普遍的多层介质宽边侧边耦合多微带线的频率特性,给出了三层介质宽边侧边耦合四微带线的特性阻抗及等效介电常数的设计曲线。结果还表明该结构的偶-奇模特性阻抗Zeo随频率变化很大,当相对介电常数r较小时,变化更大。     

用直线法分析非对称支持宽边耦合共面波导的色散特性

本文利用去耦电壁与去耦磁壁模型,用直线法分析了非对称支持宽边耦合共面波导的色散特性,发现在宽频带范围其色散性相对较弱。此结果为在三维微波集成电路中应用非结称支持宽边耦合共面波导电路时,在0-20GHz频带范围内近拟采用准静态方法进行电路分析与设计提供了理论依据。     

有限尺寸介质基片上的共面波导

有限尺寸介质基片上的共面波导是一种非常接近于工程应用状态的物理模型.本文用共形映射技术分析有限尺寸介质基片上的共面波导,得到了它的单位长度电容、有效介电常数和特性阻抗等基本参数,与介质基片宽度为无限大的理想化模型作了比较,给出了介质基片为多宽可以认为是无限宽的判别公式.     

一种共面波导结构双模圆环带通滤波器

提出了一种新型的用共面波导馈线结构实现的双模圆环带通滤波器。该滤波器采用传统的圆环作为谐振器,引入阶梯阻抗作为微扰使其简并模式分离并产生耦合。这样的微扰结构我们称之为环形阶跃阻抗谐振器,它与输入/输出共面波导分别设计在介质基片的两个不同的面上。文中给出了该滤波器的结构及通过仿真和实验获得的性能参数,结果表明该滤波器在带宽为11.4%时通带内的最小插损为1.42dB。     

CMOS 0.13 μm共面波导建模与特性分析

基于TSMC0.13μmCMOS工艺,对深亚微米硅基上的共面波导特性进行了研究。在分析中引入了保角映射等数值方法,给出了有效介电常数εeff、特征阻抗Z、单位电容C等传输线指标随几何参数变化的计算公式。并设计了特征阻抗分别为50Ω和70Ω的共面波导传输线元件库。采用Short-Open-Load-Thru(SOLT)校准测试技术对片上传输线元件库进行测试。在0.1~40GHz范围内,测试结果与数值分析解吻合。这为在硅基上进行RFIC设计提供了一个合理选取传输线结构的方法。     

奇模抑制孔缝阵列速度补偿型弯曲共面波导

提出了一种可以抑制奇模的速度补偿型弯曲共面波导结构。该结构采用在弯曲共面波导较长缝隙中的介质上打孔的方式降低其等效介电常数,加快该缝隙中的电波速度,从而使得较长缝隙中的信号经过弯曲段后与较短缝隙中的信号同相输出。仿真和实验结果表明：所提出的结构可以有效抑制奇模辐射,显著降低传输损耗和减小反射。     

共面波导表面状态对微波性能影响分析

针对共面波导表面状态对微波性能影响进行了分析,应用保角变换法定量给出了共面波导金属厚度与有效介电常数、特征阻抗、损耗修正表达式。测量了工程中常用的不同工艺制作的共面波导传输线导体厚度、表面粗糙度等参数。采用仿真软件模拟不同导体厚度、不同导体表面粗糙度对微波传输性能的影响。在追求低传输损耗的工程应用中,要考虑共面波导导体厚度、表面粗糙度等表面状态的影响,选择合适的工艺手段和合理的工艺精度来保证传输线的微波性能。     

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...     

共面波导有限金属厚度效应的研究

用保角变换法对共面波导金属厚度效应进行了理论分析，编制了相应的计算机程序，给出了数值解，并对此进行了多元曲线拟合，导出了考虑金属厚度后的形状比k、有效介电常数、特征阻抗、损耗的闭定表达式。用此修正表达式求得特征阻抗及损耗的数值解，并与K．C．格普塔的修正值及实验测量值进行了详细比较，结果表明此修正公式与实验值相符较好。     

Full-Wave Analysis of Inside Cylindrical Microstrip Lines by Finite Element Method

In this paper, a full-wave analysis using finite element method is presented to investigate the dispersion characteristics of inside cylindrical microstrip lines, which are essential to the design of some conformal microstrip circuits in millimeter wave bands. Numerical results of frequency-dependent effective dielectric constants are given for different structural dimensions and dielectric constants of substrate. Some useful conclusions are derived for the design of the special conformal microstrip lines.     

LSA relaxation oscillator principles

Oversized n-GaAs diodes operating in the LSA mode with doping-to-frequency ratios in the 1-5×10⁵s/cm³range are investigated in circuits that contain a short-circuited high impedance transmission line foreshortened to resonate the electronic parallel capacitance of the diode. By comparing computer simulations with experiments, such diodes are shown to operate in a nonsinusoidal LSA relaxation mode which offers good efficiency, effective space-charge control, and a fast buildup of the oscillations; details of the computer program are also given. A simple analysis is developed which defines the inductive and capacitive time constants controlling the voltage waveshape and explains the frequency tuning with bias voltage and the effective space-charge control. The analysis is shown to be suitable for oscillator design purposes.     

涂层圆柱爬行波传播常数和模式阻抗的分析与计算

本文分析了介质涂层圆柱爬行波的电磁特性。找到了一种求解爬行波传播常数和模式阻抗的有效方法－微扰－迭代法，这种方法简单、快速，便于工程应用。最后给出公式并计算了一些实例。     

Parameters of Microstrip Transmission Lines and of Coupled Pairs of Microstrip Lines

A theoretical analysis is presented of microwave propagation on microstrip, with particular reference to the case of coupled pairs of microstrip lines. Data on this type of transmission line are needed for the design of directional couplers, filters, and other components in microwave integrated circuits. The inhomogeneous medium, consisting of the dielectric substrate and the vacuum above it, is treated in a rigorous manner through the use of a "dielectric Green's function" which expresses the discontinuity of the fields at the dielectric-vacuum interface. Results are presented in graphical form for substrate dielectric constants of 1, 9, and 16, and a range of values of width and spacing of the strips. Numerical tables for these and other cases are also available. The tables present capacitance, characteristic impedance, and velocity of propagation of the even and odd normal modes. The method lends itself to the treatment of other geometries which are of practical interest, such as "thick" strips, presence of an unsymmetrically located upper ground plane, etc.     

自由振动压电振子的一种复参数等效电路

将复数概念引入到等效电路元件参数中,并以自由振动压电振子的一种常用振动模——纵向长度伸缩振动模为例,给出了一种复参数等效电路,并推导了等效电路参数与压电材料参数之间相互关系。等效电路元件参数的虚部表示压电振子机械、介电、及压电损耗。给出了由复参数等效电路模型作出的阻抗圆图与由振动理论给出的阻抗圆图以及由传统模型所作出的阻抗圆图。结果表明,新的复参数模型优于传统模型,是一种精确的等效电路。     

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.     

Numerical Analysis of Shielded Coplanar Waveguides

A numerical method is presented to calculate the impedance and the effective dielectric constant for a coplanar waveguide with a ground plane under a thin dielectric. Impedance and effective dielectric constant values are given as a function of geometry for GaAs and alumina substrates. An approximate analytical expression is given to generate the numerical value of the impedance with good accuracy. The results can be used in designing shielded coplanar waveguides. Measurements of a tapered 50-Omega test structure are presented.     

Propagation constants and coupling properties of coupled trapped image waveguide

The odd and even mode propagation constants of uniformly coupled trapped image waveguides are calculated by using the methods of the effective dielectric constant and surface impedance matching. Theoretical characteristics of a coupler made of coupled trapped image waveguides are analyzed and they can be used as a foundation for the design of this kind of coupler.     

Broadband CPW fed stacked patch antenna

A broadband CPW fed stacked patch antenna well suited for integration with monolithic and optical integrated circuits is presented. The antenna is designed with a bandwidth of 40% on a high dielectric constant feed substrate. The predicted and measured input impedance and far field radiation patterns are given