know, how to find the Gamma_S andGamma_L. I don't know , how to find the admittance point Ys
2019-01-14 08:20
亲爱的先生，如何使用ADS2009找到微波电路中两点之间的阻抗。 以上来自于谷歌翻译 以下为原文Dear Sir, How to find the impedance between two points in microwave circuit using ADS2009.
2019-02-18 13:32
有谁知道是否可以显示集总元件射频滤波器的节点电压？我给出了节点名称，但不知道如何在频率上显示这些节点的电压。我有一个带有s参数输入组件的2端口电路。在Vdc的终止实例中有一个设置，我假设它设置了最大输入电压（？）。任何帮助，将不胜感激。谢谢。 以上来自于谷歌翻译 以下为原文Does anyone know if it's possible to display node voltages for a lumped element rf filter?I have given the nodes names but don't know how to display the voltages at those nodes over frequency.I have a 2-port circuit with s-parameter input component.There is a setting in the termination instances for Vdc which I assume sets the max input voltage (?). Any help would be appreciated. Thanks.
2019-04-25 15:36
传输线设计是高频有线网络、射频微波工程、雷射光纤通信等光电工程的基础，为了能让能量可以在通信网路中无损耗地传输，良好的传输线设计是重要关键。 无线通信加上视频技术将成为未来的明星产业，要达到这个目标，负责传送射频微波信号的介质除空气之外，就是高频的传输线。人类目前无法控制大气层，但是可以控制射频微波传输线，只要设法使通信网路的阻抗能相互匹配，发射能量就不会损耗。本文将从阻抗匹配的角度来解析射频微波传输线的设计技术。
2019-06-20 08:17
考虑一种同轴电缆，其外导体“O”具有无限长度，但内部导体“I”具有一定的有限长度，正如我试图用下面的ASCIII图形所示。今晚我喝了不少啤酒，所以不要想我试图在图形包中画这个啤酒！观察到左侧的S参数是否已经被异步地推进并且已经发表了？具有足够的S-参数是否已经被发现？如果是这样，有没有人有参考？显然，这样的结构作为校准标准相对容易制作* IF *这些属性可以在理论上得到。我可以想象这是某种人可能想要解决的结构，我可以想象有可能达到解决方案。我也可能会假设它会涉及贝塞尔函数，这对于驱逐程序来说是非常重要的。如果内部被翘曲，但是被电介质D支撑则更有用，例如，如使用安捷伦的EMPro或Ansys的HFSS这样的3D EM求解器，当然可以相当容易地用数字方式来推测S参数，这是非常有用的。 ，但我想知道是否有人对这些结构中的任何一个都有理论解决方案？ Dave.Edited：drkirkby于2013年7月28日下午10:48 以上来自于谷歌翻译 以下为原文Consider a coaxial cable which has an outer conductor "O" of infinite length, but an inner coductor "I" of some finite lenght, as I've tried to show with ASCIII graphics below. I've had quite a few beers tonight, so don't fancy my chances trying to draw this in a graphics package!!! OOOOOOOOOOOOOOOOOOOOOOOOOOOO IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII OOOOOOOOOOOOOOOOOOOOOOOOOOOO Have the S-parameters looking into the left hand side ever been derrived theoertically, and published? If so, does anyone have a reference? Clearly such a structure would be relatively easy to make as a calibration standard *IF* the properties could be derrived theoretically. I can imagine it is the sort of structure someone might have thought to solve, and I can imagine it might be possible to arrive at a sollution. I might also postulate it would involve Bessel functions an be non-trivial to derrive. Even more useful would be the case if the inner was tructated, but supported by a dielectric D, as in OOOOOOOOOOOOOOOOOOOOOOOOOOOOO IIIIIIIIIIIIIIIIIIIIIIIIIIIIIDDDDDDDDDDDDDD OOOOOOOOOOOOOOOOOOOOOOOOOOOOO It would of course be fairly easy evualate the S-parameters numerically with a 3D EM solver such as Agilent's EMPro or Ansys's HFSS, but I wonder if anyone has a theoretical solution to either of these structures? Dave.Edited by: drkirkby on Jul 28, 2013 10:48 PM
2019-01-17 10:51
阻抗匹配（Impedance matching）是微波电子学里的一部分，主要用于传输线上，来达至所有高频的微波信号皆能传至负载点的目的，几乎不会有信号反射回来源点，从而提升能源效益。阻抗匹配有两种，一种是透过改变阻抗力（lumped-circuit matching），另一种则是调整传输线的波长（transmission line matching）。要匹配一组线路，首先把负载点的阻抗值，除以传输线的特性阻抗值来归一化，然后把数值划在史密斯图上。
2019-06-24 08:08
首先，祝大家圣诞快乐。我花了一些圣诞节来讨论我的8720D VNA - 它是由我个人拥有的，因此在我的家里，所以它不像它看起来那么不干净！我感兴趣的是看一个未连接的公N连接器是否可以用作“开放式”校准设备，如果是，那么哪个参数最好。好吧，我知道它可以完成，因为FieldFox系列上的QuickCal可以做到这一点，但当然我需要参数进入VNA。如果他们是安捷伦的老手，我也不会感到惊讶。首先使用适当的'N'校准套件（85032B）进行校准后，我注意到以下情况。 1）令我惊讶的是，开放式N似乎不是电容性的，因为我认为由于边缘电容。相反，它似乎是归纳的。是否能够通过值为2的电容器来表示电感。中心导体位于参考平面下方约1 mm。鉴于真空中的光速为299792458 m / s，这表明输入的偏移应为-0.001 / 299792458 = -3.335 ps。那有意义吗？也许值得说明偏移几ps - 使其更负面，因此可以将电容作为正值输入。我不确定这是否比使用负电容更好或更差。对于它的价值，我最初尝试通过曲线拟合找到C0，C1，C2和C3的合理值并不太成功，但我怀疑它有更多的时间可能是可行的。如果有人试过这个，或者知道参考文献，我会感兴趣的。你可能觉得我很生气，但现在是圣诞节，所以我喝了一两杯啤酒！有了这一切，一切顺利。我要去爱尔兰咖啡吧！ （这在英国很受欢迎 - 对美国不太确定。我猜你可以用杰克丹尼尔威士忌制作它。）如果我说实话，我用一种廉价的苏格兰威士忌制作“爱尔兰咖啡”。我认为将更昂贵的爱尔兰威士忌放入咖啡中是不合理的。戴夫 以上来自于谷歌翻译 以下为原文First of all, merry Christmas to everyone. I've spent some of Christmas day messing around with my 8720D VNA - it is personally owned by me, hence in my home, so it was not quite as unsociable as it might appear! I was interested in see if an unconnected male N connector could be used as an "open" calibration device, and if so what parameters would be best. Well, I know it can be done, as the QuickCal on the FieldFox range do this, but of course I needed the parameters to enter into the VNA. and I would not be surprised if they are proprietry to Agilent. I noticed the following, after first calibrating with a proper 'N' calibration kit (85032B). 1) Much to my surprise, the open-N does not appear to be capacitive, as I would have thought due to the fringing capacitance. Instead, it appears inductive. Would it make sence to represent an inductance by capacitor of a value < 0 ? I found it is possible to enter negative values for all value C0, C1, C2 and C3. . 2) The centre conductor sits below the reference plane by about 1 mm. Given the velocity of light in a vacuum is 299792458 m/s, that would suggest the offset to be entered should be -0.001/299792458 = -3.335 ps. Does that make sense? Perhaps it is worth lying about the offset by a few ps - making it even more negative so it is possible to enter the capacitance as a positive value. I'm not sure if that would be better or worst than having negative capacitors. For what it is worth, my initial attempts to find sensible values for C0, C1, C2 and C3 by curve fitting were not too successful, but I suspect with more time it might be workabe. If anyone has ever tried this, or knows of a reference, I'd be interested. You probably think I am mad, but it is Christmas day, so I have had a beer or two! With that, all the best. I'm going to have an Irish Coffee! (That's quite popular in the UK - not so sure about the USA. I guess you could make it with Jack Daniels whisky.) If I'm honest, I make an "Irish Coffee" using a cheapish Scotish whisky. I think putting the more expensive Irish whisky in a coffee is not justified. Dave
2019-04-28 11:34
嗨，我正在开展一个需要表征SOLT校准套件的项目。该套件代表从3.5mm SMA连接器到长度为20mm的微带线的过渡。对3GHz以上频率的测量需要将开放边缘电容模型化为3阶多项式。我执行以下步骤：在测试电缆末端进行1- 1端口校准（85033D校准套件）。 2-连接短标准（20mm 50欧姆微带线由2个并联的50欧姆电阻器结束）并使端口扩展直到180度相移。 3-断开短标准并连接开放标准。 4-调整延迟直到相位为负（整个波段的负相位）。 5-提取格式化的RI数据并跟踪并行电容值作为频率的函数。 6-使用数学工具拟合图形以评估电容多项式的系数。注意，如果我们想要整个工作频带的负相位，则开路相位线路既不是平坦的也不是线性的，并且在频带末端（6 GHz）达到-28度。我的问题是电容多项式的系数值很大。 （C0 = 38.33E-15; C1 = 79676.1E-27; C2 = -35687.91E-36; C3 = 4270.35E-45）。 VNA不接受超过10000或小于-10000的值。实际上，我试图将乐队划分为两个子乐队，但同样的问题也会出现。此外，我试图最小化频带以实现平坦相位（小于1度的变化），但也出现同样的麻烦。谢谢你的帮助。 以上来自于谷歌翻译 以下为原文Hi, I'm working on a project that needs the characterization of a SOLT calibration kit. The kit represents a transition from 3.5mm SMA connector to a microstrip line of length 20mm. The measurement for frequencies above 3GHz requires the modelization of the open fringing capacitance as a polynomial of order 3. I perform the following steps: 1- 1-port calibration at the end of the test cable (85033D calibration kit). 2- Connect short standard (20mm 50ohm microstrip line ended by 2-parallel 50ohm resistors) and make port extension until 180 degrees phase shift. 3- Disconnect short standard and connect the open one. 4- Adjust the delay until the phase is negative (Negative phase across the whole band). 5- Extract the formatted RI data and trace the parallel capacitance values as a function of frequency. 6- Use mathematical tool to fit the graph in order to evaluate the coefficients of the capacitance polynomial. Note that the open phase trace is neither flat nor linear and reaches -28 deg at the end of the band (6 GHz) if we want negative phase for the whole operating band. My problem is that the values of the coefficients of the capacitance polynomial are big. (C0=38.33E-15; C1=79676.1E-27; C2=-35687.91E-36; C3=4270.35E-45). The VNA doesn't accept values more that 10000 or less than -10000. Actually, I tried to divide the band into two sub-bands, but that same problem results. Moreover, I tried to minimize the band in order to achieve flat phase (less than 1 deg variation) but also the same trouble arises. Thanks for your help.
2019-05-08 07:44
