如何验证校准负载固定负载在3 GHz以下的52 dB URL？

这是一个很好的问题，我不确定我们做了什么，我将不得不检查出来。
显然，DC值很容易验证。
可以使用更长的线路TRL套件验证低至某些低频率（轻松低于1 GHz）的值。
我可以从DC值和来自TRL的中频数据猜测，可以开发负载模型，假设负载响应由可以与高频数据匹配的RLC模型支配。
因此，如果你测量一个负载并且你看到它在1 GHz时有10个电感pH值，在DC时有50.2欧姆，你可以推断出它们之间的响应，但假设有一些关于负载结构的知识。
长线也可能相当合理，低于1 GHz，TRL线约为16 mm，可提供足够的相移。
标准的10厘米航空公司应该可以降低到200 MHz以下。



     以下为原文

  That's a good question, I'm not sure exactly what we do, I'll have to check it out.

Obviously the DC value is easy to verify.  The value down to some low frequecy (easily below 1 GHz) can be validated with longer line TRL kits.

I would guess from the DC value and the mid-frequency data from TRL, that a model for the load could be developed, presuming  the load response is dominated by a RLC model that can be matched to the high frequency data. So, if you measure a load and you see that it has 10 pH of inductance at 1 GHz, and 50.2 ohms at DC, you can infer the response in-between, but the presumes some knowledge of the load contruction.

Long-lines is probably also quite reasonble to below 1 GHz, with a TRL line of about 16 mm giving enough phase shift.  A standard 10cm airline should get you down to below 200 MHz.

谢谢你的快速，如果只是部分响应，我通过在DC测量它们并且具有一组三个负载来解决这个问题，我已经任意地说它们必须彼此达到> 55dB rl，直到感兴趣的频率
审计师已将其标记为有问题，因此我正在寻找一个更“绝对”的过程



     以下为原文

  Thank you for a very quick if only partial response , I get around this problem by measuring them at DC and having a set of three loads that I have arbitrarily said must  agree with each other to >55dB rl up to the frequency of interest this however has been flagged by an auditor for being questionable  and as such I am looking for a more “absolute” process

看起来我的直觉是正确的;
来自我们的内部计量学家：德鲁：“我们确实使用长线来降低到200 MHz并测量直流然后插入直流值。我们不会仅使用另一个负载。我们使用负载（ETs）
）专门为DC和低频性能而选择。已经发布。“
并且：詹姆斯：“事实上，我们使用低至200MHz的TRL和DC测量值。在DC到200MHz之间我们进行了间接操作，我在座位上留下了对纸张使用的参考。如果您有其他问题，请来看我。”
参考文献（来自我们在NPL的好朋友）：Ridler，N.M。;
Salter，M.J。;
Young，P.R。;
，“用于中频精密反射系数测量的插值方案.II。实际实施，”仪表和测量技术会议，2001年.IMTC 2001.第18届IEEE会议论文集，第3卷，第1期，第1731-1735卷
.3,2001 doi：10.1109 / IMTC.2001.929497摘要：用于推导中频（IF）范围内短路，开路和匹配负载同轴反射仪校准标准的电压反射系数的插值方案的实际实现是
描述（其中，广义上讲，IF指的是DC到100MHz的频率范围）。
该方案允许使用商业上可获得的设备（而不是专门构造的可计算设备）作为反射计校准标准，其VRC值可溯源至国家测量标准。
提供了测量结果，说明了方案URL的功能：http：//ieeexplore.ieee.org/stamp/stamp.jsp？tp =＆amp; ofumber = 929497＆amp; isnumber = 2009现在您有一个完整的答案。



     以下为原文

  Looks like my intuition was right; from our in-house metrologists:
Drew: "We do use long lines to get down to 200 MHz and measure DC and then interpolate to the DC value. 
We don't use just another load to c al with. 
We use loads (ETs) specially selected for DC & low frequency performance.
This has been published."

and:
James: "Indeed we use TRL down to ~200MHz and the DC measured value.  Between DC to 200MHz we interopolate,  I left a reference to the paper use on your seat.  Come see me if you have additional questions."

And the reference is (from our good friends at NPL):
Ridler, N.M.; Salter, M.J.; Young, P.R.; , "An interpolation scheme for precision reflection coefficient measurements at intermediate frequencies. II. Practical implementation ," Instrumentation and Measurement Technology Conference, 2001. IMTC 2001. Proceedings of the 18th IEEE , vol.3, no., pp.1731-1735 vol.3, 2001
doi: 10.1109/IMTC.2001.929497
Abstract: The practical implementation of an interpolation scheme for deriving the voltage reflection coefficients of short-circuit, open-circuit and matched load coaxial reflectometer calibration standards in the intermediate frequency (IF) range is described (where, broadly speaking, IF refers to the frequency range DC to 100 MHz). The scheme allows the use of commercially available devices (rather than specially constructed calculable devices) as reflectometer calibration standards with VRC values traceable to national measurement standards. Measurement results are presented which illustrate the capabilities of the scheme
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=929497&isnumber=20096

And now you have a complete answer.

非常感谢Dr_Joel，这确实是一个非常完整的答案



     以下为原文

  Thank you very much Dr_Joel , this is indeed a very complete answer