如何在8510上的TRL校准中使用Z0

根据我的理解，如果选择“线Z0”作为校准参考Z0，则在TRL校准之后，所有DUT S参数将参考线Z0，例如42.5欧姆。
有些情况下，PCB上的DUT具有85欧姆的差分特性阻抗，并且PCB上的所有TRL校准套件标准设计为具有42.5欧姆Z0。
通过选择线路Z0作为校准参考Z0，您可以方便地获得以85欧姆（差分）为参考的DUT S参数如果选择系统Z0作为校准参考Z0，尽管所有线路标准都具有42.5欧姆的特征阻抗，在TRL之后
校准时，您的DUT S参数将参考系统Z0（默认为50欧姆）。
Cal仍然有效，并且正确测量了S参数。
但是，如果您希望DUT S参数参考42.5欧姆，则还需要一步：使用端口Z转换将所有端口参考阻抗更改为42.5欧姆。
这与将Cal Reference Z0直接设置为42.5 Ohm完全相同。



     以下为原文

  In my understanding, if you select "Line Z0" as the Cal Reference Z0, after TRL calibration, all the DUT S-parameters will be referenced to the Line Z0, such as 42.5 Ohm. There are cases that the DUT on PCB have 85 Ohm differential characteristic impedance, and all the TRL cal kit standards on PCB are designed to have 42.5 Ohm Z0. By selecting Line Z0 as the Cal Reference Z0 you can conveniently get DUT S-parameters that are referenced to 85 Ohm (differential)

If you select System Z0 as your Cal Reference Z0, although all the Line standards have 42.5 Ohm characteristic impedance, after TRL calibration, your DUT S-parameters will be referenced to System Z0 (default to 50 Ohm). The Cal still works and the S-parameters are measured correctly. But if you want your DUT S-parameters to be referenced to 42.5 Ohm, you need one more step: use Port Z Conversion to change all the port reference impedance to 42.5 Ohm. This is exactly the same as setting the Cal Reference Z0 to 42.5 Ohm directly.

感谢您的答复。
我需要知道校准误差系数（校准后可以从8510读出）是否实际上是参考线Z0或系统Z0（替代方案是测量和误差校正的S参数可以转换为参考
到不同的阻抗）。
如果确实正在转换误差系数，那么如果您可以提供对转换背后的数学的引用，那将是一个很大的帮助。



     以下为原文

  Thank you for the reply.

I need to know whether the calibration error coefficients (that you can read out from the 8510 after calibration) are in fact referenced to the Line Z0 or System Z0 (the alternative would be that measured and error-corrected S parameters can be transformed to refer to a different impedance).

If indeed the error coefficients are being transformed, it would be a big help if you could provide a reference to the maths behind the transformation.