如何检查电缆和校准套件

这是一个非常开放的问题！
什么类型的连接器？
什么频率？
这就是你的全部吗？
你有另一个校准套件吗？
我假设你有一台网络分析仪，对吗？
您对相位还是幅度感兴趣？
稳定性怎么样？



     以下为原文

  That's a pretty open ended question!
What type of connectors?  What frequency? Is that all you have?  Do you have another cal kit?
I assume you have a network analyzer, right?
Are you interested in phase or just magnitude?  What about stability?

N型连接器，高达3Ghz。
我有一台HP 8752A。
检查不同供应商的校准套件质量和不同的供应商电缆如何检查以查看差异？
我的意思是VNA cables.Edited：theamberco于2013年12月14日下午1:58



     以下为原文

  N type conectors, upto 3Ghz. I have an HP 8752A. Check different vendors cal kits quality and different vendors cables how can this be checked to see the difference?
I mean VNA cables.

Edited by: theamberco on Dec 14, 2013 1:58 PM

在许多情况下，最重要的方面是匹配和传输的稳定性。
它们很容易测试。
要测试匹配不确定度，请连接短路，选择data-> mem和data-mem（数据MINUS存储器）。
将格式设置为logmag。
结果应在-50到-60 dB左右。
前后弯曲电缆并观察最高峰。
如果最高峰值小于-50 dB，则它是计量级电缆，如果最高峰值小于-35 dB，则它是生产质量的电缆。
如果最高峰值低于-20 dB，则不值得使用。
传输类似，切换到data / mem并以logmag和阶段查看响应。
小于0.02 dB（和0.12度）是计量等级......等。



     以下为原文

  For many cases, the most important aspect is stabiltiy of match and transmission.

They are easy to test.  To test match uncertainty, connect a short, select data->mem and data-mem (data MINUS memory).  Set the format to logmag.  The result should be around -50 to -60 dB.  bend the cable back and forth and observe the highest peaks.  If the highest peaks are less than -50 dB, it is a metrology grade cable, if the highest peaks are less than -35 dB, it is a production quality cable.  If the highest peaks are worse than -20 dB, it is not worth using.

Transmission is similar, switch to data/mem and view the response in logmag and in phase.  Less than 0.02 dB (and 0.12 deg) is metrology grade...etc.

感谢Joel，就像我刚刚购买你的书一样，我在亚马逊的预览中看到了一些，并且非常推荐给我。
我将在下个月的某个时候收到它。
还有两个问题：有没有办法用可用的测试设备来检查校准质量。
不同供应商的套件？
你有其他书还是有计划再写了？



     以下为原文

  Thanks Joel, by the way I just purchased your book, I saw some of it in the amazon preview and it was highly recomended to me. I will receive it some time next month.
Two more questions:
Is there a way with available test equipment to check the quality of cal. kits from different vendors?
Do you have any other books or have plans to write anymore?

不，现在计划中没有任何内容。
我描述的电缆测试场景也在我的书第596-599页中说明。
第3章对确定残留误差有一些建议，这与评估校准套件几乎相同。
关键方面是您需要具有已知或预期性能的某些东西，然后在使用不同套件校准后进行测量。
根据校准类型（SOLT，Unknown Thru，QSOLT，TRL），您可以进行不同的实验。
一个简单的方法是进行传统的SOLT测量，然后测量更长的电缆，并查看S21和S12。
如果它们不同，那么它指向校准套件中的错误。
使用多个校准套件进行校准，测量S21和S12，并将差值（以dB为单位）作为测量的品质因数。
你可以通过数据 - > mem然后数据/ mem（数据/ mem是复杂的形式）来获取dB的差值，因此在logmag中，它将显示以dB为单位的差异。
只要电缆弯曲不限制测量质量，提供最低差异的套件可能是最好的。



     以下为原文

  No, nothing in the plans for now.

The cable test scenario I described is also illustrated in my book on pages 596-599.  Chapter 3 has some advice on determining residual errors, which is nearly the same thing as evaluating a calibration kit.

The key aspect is you need to have some thing that has a known or expected performance, and then measure it after calibrating with different kits.

Depending upon the cal-type (SOLT, Unknown Thru, QSOLT, TRL) you can do different experiments.

A simple one is to do the traditional SOLT measurement, then measure a longer piece of cable, and look at S21 and S12.  If they are different, then it points to an error in the cal kit.

Calibrate with several cal kits, measure S21 and S12, and take the difference (in dB) as a figure of merit for the measurement.  You can take the difference in dB by taking data->mem and then data/mem (data/mem is in complex form, so in logmag, it will show the difference in dB).

The kit that gives the lowest difference is probably the best, as long as cable flexure isn't limiting the quality of the measurements.

> {quote：title = Dr_joel写道：} {quote}>一个简单的方法是进行传统的SOLT测量，然后测量更长的电缆，并查看S21和S12。
如果它们不同，那么它指向校准套件中的错误。
Joel，S21和S12之间的差异是优秀/好/差？
应该使用什么样的电缆 - 是否需要有几dB的损耗，或者只是一点点的确定？
我不知道你是否见过Rohde＆amp;
Schwarz T-checker：http：//www.rohde-schwarz.co.uk/file/1ez43_0e.pdf它基本上依赖于无损3端口网络的9个S参数之间的数学关系。
一个端口以某个任意阻抗终止，测量两个未端接端口的4个S参数，然后从这4个S参数计算一些因子。
越接近1.0，校准越好。
原则上它可以由低成本的T型接头制成，但我不知道损耗的影响是什么，因为所有的理论都取决于它是无损的。
戴夫



     以下为原文

  > {quote:title=Dr_joel wrote:}{quote}

> A simple one is to do the traditional SOLT measurement, then measure a longer piece of cable, and look at S21 and S12.  If they are different, then it points to an error in the cal kit.

Joel,
what magnitudes of differences between S21 and S12 are excellent/good/poor ? what sort of cable should one use - does it need to have a few dB of loss, or is just a short bit ok? 

I don't know if you have ever seen the Rohde & Schwarz T-checker:

http://www.rohde-schwarz.co.uk/file/1ez43_0e.pdf

It basically relies on a mathematical relationship between the 9 S-parameters of a lossless 3 port network. One terminates one port in some arbitrary impedance, measures the 4 S-parameters at the two unterminated ports, then computes some factor from those 4 S-parameters. The closer that is to 1.0, the better the calibration. In principle it could be made from a low-cost T-junction, but I don't  know what the effect of the losses are, since all the theory depends on it being lossless. 

Dave