一种计算单模波导输出的快速方法及其在结构优化中的应用

提出了一种快速准确的新方法,用以计算入射场耦合到波导的能量.这种方法将BPM(beam propagation method)和叠加积分法结合起来,克服了单独用BPM计算场分布的效率较低的缺点,同时也克服了叠加积分只适用于计算规则波导的缺点,该方法称为正交过滤法.用这种快速方法对星型耦合器中输出波导的锥形波导形状曲线进行优化以获得最大的耦合能量.     

AWG中阵列波导耦合系数的计算

针对阵列波导光栅（AWG）中阵列波导耦合系数的计算问题，提出了基于光束传播方法（BPM）的叠加积分方法的修正方法。将修正前、后的结果与简单叠加积分方法的结果作了分析比较，从而验证了修正方法的正确性。分析了阵列波导之间的耦合对耦合系数的影响，阵列波导间距越小，影响越大。     

一种电—光聚合物波导器件的结构优化计算

本文利用以Ｈｅｒｍｉｔｅ－Ｇａｕｓｓ函数为基函数的Ｇａｌｅｒｋｉｎ方法，对德国赫兹研究所正在研制的一种电－光聚合物波导器件进行了结构优化计算。     

一种波导结构的快速连接测试探头的设计

本文介绍了一种适用于快速大批量测试的采用扼流槽结构的波导连接探头的设计方法。这种探头有不用上螺钉即插即测、不带法兰、接头体积小、有一定容差的特点。并在文中给出了实际测试结果。     

一种快速求解波导模式瞬态响应的新方法

应用有限积分技术,构造出一种快速求解波导特征模瞬态响应的时域有限差分格式。应用该方法计算的结果与通常三维的时域有限差分方法计算的结果十分吻合,但该方法具有很高的计算效率。在新的差分格式下,通过人工添加损耗项,构造出一种新的损耗传输线模型;该方法改善了截断边界条件对虚假反射回波的吸收性能,使虚假的反射回波低于-60dB。     

一种新型的回旋管用多波导输出系统

该文提出了一种用于回旋管的多波导输出结构。利用 高频计算软件,对这种结构进行了数值模拟,通过对各相关尺寸进行合理选择以及模式转换过程的优化,不仅有效实现了工作模式之间的输出转换,同时在一定程度上降低了竞争模式对工作模式的影响。在Ka波段,获得了对驻波比小于1.5情况下,从TE01○到TE10□模输出能量转换效率大于95.9%和带宽接近 3%的结果。     

TLM方法在计算方波导的截止频率中的应用

传输线矩阵(TLM)是一种强有力的时域和空域电磁场数值仿真算法,它的出现在各个领域引起了广泛关注.文中在简单介绍TLM原理后,对方波导的截止频率用Matlab语言进行编程计算,计算结果与理论计算值吻合.基于Huygens波传播模型的传输线矩阵方法与计算机结合起来后,成为一种强有力的时域电磁场数值仿真算法.     

一种新型光波导及其在光衰耗器中的应用

本文介绍一种能用于可调谐光衰耗器的新型光波导,其包层为金属汞,包层长度灵活可变。理论分析和实验均表明,这种光波导的光功率衰耗与包层长度成正比,在１．３μｍ光波长,当芯径为４００～６２μｍ时,应对光功率的衰减为０．０４～０．１６ｄＢ／ｍｍ,。以此光波导为基础的可调谐光衰耗器具有结构简单、性能优越等特点,其测量精度可达０．３ｄＢ。     

一种分析波导系统不连续性的数值计算方法

本文介绍一种分析波导不连续性的数值计算方法 ,采用有限差分法和共轭梯度法对根据矢量偏微分算子理论得出的电磁波基本方程进行求解 ,由此计算出反射系数和传输系数 ,文中以加载金属膜片的矩形波导为例说明了这一计算过程     

一种计算波导耦合缝隙有源阻抗的方法

 针对耦合波导缝隙馈电时波导内电磁场复杂且不利于工程应用的问题,提出一种耦合波导缝隙有源阻抗计算方法.根据耦合波导端口处S矩阵与端口处输入阻抗矩阵的关系建立关于耦合波导缝隙有源阻抗方程,且采用牛顿法求解此非线性高阶分式方程,得到计及缝隙间互耦的耦合波导缝隙有源阻抗值.通过提取HFSS软件中耦合缝隙馈电的裂缝天线S矩阵进行仿真计算,结果表明该计算耦合缝隙有源阻抗的方法是有效的且适合大型裂缝天线耦合裂缝设计.     

Characteristic Analysis of Diffraction from the Restricted Output End Surface of Single Mode Planar Waveguide

As for single mode symmetric step refractive index structure dielectric planar optical waveguide, when its output end is restricted, the diffractive field distribution is derived. It can be expressed as the convolution between the Dirac function and the Sinc and Lorenz functions. It is helpful to deepen the recognition of the restricted diffraction. The characteristic of the diffractive field is discussed. The variational curve of the full angle width at half maximum intensity of central bright fringe versus the half width of slit is presented by numerical calculation, and the fitting curve with the exponential function is close to it.     

A Frequency-Dependent LOD-FDTD Method and Its Application to the Analyses of Plasmonic Waveguide Devices

Detailed frequency-dependent formulations are presented for several efficient locally one-dimensional finite-difference time-domain methods (LOD-FDTDs) based on the recursive convolution (RC), piecewise linear RC (PLRC), trapezoidal RC (TRC), auxiliary differential equation, and ${mmb Z}$ transform techniques. The performance of each technique is investigated through the analyses of surface plasmon waveguides, the dispersions of which are expressed by the Drude and Drude-Lorentz models. The simple TRC technique requiring a single convolution integral is found to offer the comparable accuracy to the PLRC technique with two convolution integrals. As an application, a plasmonic grating filter is studied using the TRC-LOD-FDTD. The use of an apodized and a chirped grating is found quite effective in reducing sidelobes in the transmission spectrum, maintaining a large bandgap. Furthermore, a plasmonic microcavity is analyzed, in which a defect section is introduced into a grating filter. Varying the air core width is shown to exhibit tunable properties of the resonance wavelength.      

应用于跨导放大器设计的线性度优化方法

 基于跨导放大器线性度理论和数学分析,提出了一种提高线性度的方法.该方法通过数学理论分析和模拟实验证实,双端输入双端输出结构的跨导器线性度优于单端输入单端输出的跨导器,且两个输入端信号满足一端是另一端幅度的4/3倍加1时,跨导器线性失真度最小.根据该优化方法设计了一种新型跨导器,仿真实验表明,跨导器无杂散动态范围为60.25dB,噪声平台达到-100dB.     

An Analytical Design and Analysis Method for a High-Power Circular to Rectangular Waveguide Mode Converter and Its Applications

An analytical method to estimate the scattering of RF power into multiple modes inside a nonuniform waveguide using perturbation techniques is presented. This method is quite general, much faster than numerical methods, and may be applied to a wide variety of nonuniform waveguides. We have used this method to design and analyze a three-section mode transformer that converts a ${rm TE}_{01}$ circular waveguide mode to a ${rm TE}_{20}$ rectangular waveguide mode. This mode converter is specially suitable for use in ultra-high-power applications. Due to the complexity of the problem, we have used the symbolic solver Mathematica to produce most of our analytical results. The results match within reasonable accuracy with High Frequency Structure Simulator field solver simulations. We also present the application of this mode converter to variety of ultra-high-power microwave components and experimentally show the performance of these devices.      

一种双模波导滤波器及应用

基于波导谐振器模式分析理论,文中介绍了一种TM 双模波导谐振器,并采用该谐振器仿真设计了微波滤波器。该滤波器具有体积小、Q 值高、便于调试安装等特点。 滤波器谐振器采用了 TM120 及 TM210 双模设计,谐振器尺寸可以灵活设计,适用于多种需求。 文中采用电磁仿真软件进行了滤波器的设计及优化,并分析了多种物理结构,包括同轴结构输入输出滤波器、高阶滤波器及腔体谐振器平面排列结构的滤波器。 生产加工了一台 Ku 频段的滤波器,测试性能优良,测试数据和仿真数据一致性好。     

Application of Davidenko's Method to a Lossy Nonlinear Waveguide

Davidenko's method is implemented for determining the complex propagation constants (Modal index and attenuation coefficient) of nonlinear TE waves guided by an asymmetrical lossy nonlinear dielectric wave-guide. The waveguide structure has a generalized nonlinear substrate with a permittivity of the form ? ～ | E |^δand an absorbing cover making the propagation constant to be complex. Davidenko's method shows to be a fast and accurate analysis in finding the complex propagation constants. The effects of initial condition parameter on the propagation characteristics are investigated, analyzed and discussed.     

波导带通滤波器的精确设计和快速优化

介绍了采用三维微波电磁场仿真软件快速提取直接耦合波导带通滤波器耦合窗口参数的方法,并提出了优化最终模型的快速扫描技术.全波仿真及实验结果表明,该方法能满足波导带通滤波器快速精确设计的要求.     

Phase-Matched Waveguide Using the Artificial Anisotropic Structure and its Application to a Mode Converter (Short Papers)

Phase matching by the artificial anisotropic structure and its application to a mode converter are proposed for millimeter-wave dielectric circuitry. A phase-matched dielectric planar waveguide is designed and mode conversion characteristics are studied. An experimental result of the nonreciprocal mode converter are presented to show the usefulness of the structure.     

一种存储器低功耗优化方法及其应用

根据在特定的VLSI系统中存储器读写地址以自然顺序连续变化为主的特点,提出一种基于折叠与数据打包的结构变换方法,通过减少存储器访问次数实现功耗优化.在SMIC 0.13μm工艺条件下进行分析,结果表明:该方法以较小的面积开销,即可使功耗降低约50%.基于此方法进行优化,设计了一种适用于CMMB系统的低功耗LDPC译码器.分析表明,在面积仅分别增大1.2%和6.0%的前提下,该LDPC译码器功耗分别降低21%和33%.