The last book I purchased was not helpful. While Dunsmore's book dedicates a chapter to calibration and error correction, Bonaguide & Jarvis have only a few pages. Both books would make a very good reference and I wish I had them when I was first introduced to a VNA.
As I already said in a private mail, I have it on my to do list to check Michael Hiebel's book ("Fundamentals of Vector Network Analysis", the German version from 2006 is titled "Grundlagen der vektoriellen Netzwerkanalyse").
The last book I purchased was not helpful. While Dunsmore's book dedicates a chapter to calibration and error correction, Bonaguide & Jarvis have only a few pages. Both books would make a very good reference and I wish I had them when I was first introduced to a VNA.
As I already said in a private mail, I have it on my to do list to check Michael Hiebel's book ("Fundamentals of Vector Network Analysis", the German version from 2006 is titled "Grundlagen der vektoriellen Netzwerkanalyse").This book does not cover the Unknown Thru method in details, as well.
Only basic information is provided
...
To get rid of the assumption of a constant port match, commercial VNAs then transform the 8-term model to the conventional 12-term model (which is usually only a 10-term model by neglecting the crosstalk error terms which also do not exist in the 8-term model). The 12-term model has separate source and load port match errors for each direction. This of course, due to the larger number of unknowns, requires additional measurements: the switch terms.
The switch terms are defined as the ratio of outgoing wave and the incident wave at one port, while the other port is configured as a source. Notice that a three receiver VNA has no way of measuring them. On four receiver VNAs they are usually measured along with the thru.
...
The switch terms only depend on the test set and should not vary much over time, at least in commercial lab grade VNAs. I have checked that with my VNA, they seem to be indeed very stable.
Two different Agilent patents vs Dunsmore's book.
Two different Agilent patents vs Dunsmore's book.
I've only been briefly looking again at Section 3.2.3 in Dunsmore's book, but the notation there seems to be consistent, and I cannot spot an obvious error in the equations.
The E00, E01, E12, E11 are the error terms of the error box at port 1 of the 8-term error model, and E22,, E23, E32, E33 of the error box at port 2, see Figure 3.3. When you want to convert from the 8-term model to the 10/12-term model, the load match errors are
\[
\begin{align*}
ELR&=E_{11}+\frac{E_{10}E_{01}\Gamma_R}{1-E_{00}\Gamma_R}=E_{11}+\frac{ERF\cdot\Gamma_R}{1-EDF\cdot\Gamma_R},\\
ELF&=E_{22}+\frac{E_{32}E_{23}\Gamma_F}{1-E_{33}\Gamma_F}=E_{22}+\frac{ERR\cdot\Gamma_F}{1-EDR\cdot\Gamma_F}.
\end{align*}
\]
That is simply equations (3.8 ) together with equation (3.11) and (3.12). So it is all there in Section (3.2.3) to convert between the 8-term and the 10/12-term model. Also, the conversion from the 10/12-term model to the 8-term model is spelled out explicitly, see equations (3.13) to (3.16).
The only notational glitch I see in that section is that Dunsmore switches between, e.g., \$E_{LF}\$ and \$ELF\$, etc., in equations (3.14) to (3.16).
Edit: I should have pointed out that \$E_{11}\$ of the 8-term error model actually is equal to \$ESF\$ of the 10/12-term model. But that is a result, not just a notational oversight. Similarly, \$E_{22}=ESR\$. See equations (3.8 ).
Last official soft here:
https://zeenko.tech/litevna
Last official soft here:
https://zeenko.tech/litevna
This test FW works well on PC software (the averaging slow the process but work)
Dislord test blog on:
https://groups.io/g/nanovna-beta-test/topics
Hello Jhon, Dislord sends you the list of addresses you can join to the beta tester, seam to me one person with your experience is beneficial for all.
Best regards.
Francesco.