Hello,

IÂ´m wondering why the material measurement software needs all four S-parameters for the Nicolson-Ross-Weir-algorithm. I calculated some values on my own with the common algorithm given in the literature and I only need two S-parameters. Does the software use the mean or what?

Another problem is that I often get other results. Probably it is because I have done something wrong, but I donÂ´t find it. Perhaps the code of the software might help...

Something different: I could need some charts with permittivity/permeability over frequency for different materials for testing purposes. Can anybody give me a hint where to find such things? Especially some permeabilities would be interesting.

Thanks a lot!

AndrÃ©

[Update]

Now I got some measurement results where my calculations match the softwareÂ´s. It seems that it also uses the mean of the two S-parameter pairs. I still get slightly different results for other measurements and I canÂ´t figure out why, because IÂ´m using the same methods for the measurement and the calculation. IÂ´m wondering, if the software really is doing nothing "unusual"?

IÂ´m wondering why the material measurement software needs all four S-parameters for the Nicolson-Ross-Weir-algorithm. I calculated some values on my own with the common algorithm given in the literature and I only need two S-parameters. Does the software use the mean or what?

Another problem is that I often get other results. Probably it is because I have done something wrong, but I donÂ´t find it. Perhaps the code of the software might help...

Something different: I could need some charts with permittivity/permeability over frequency for different materials for testing purposes. Can anybody give me a hint where to find such things? Especially some permeabilities would be interesting.

Thanks a lot!

AndrÃ©

[Update]

Now I got some measurement results where my calculations match the softwareÂ´s. It seems that it also uses the mean of the two S-parameter pairs. I still get slightly different results for other measurements and I canÂ´t figure out why, because IÂ´m using the same methods for the measurement and the calculation. IÂ´m wondering, if the software really is doing nothing "unusual"?

You need only two s-parameters with Nicolson-Ross algorithm, but you will need also the exact sample position. Measuring all four s-parameters allows using approximate sample position.

When you use your own calculations for Nicolson-Ross, you should get exactly the same values as the 85071. From your update it seems that you are getting better results, but not always. For troubleshooting purpose you can email an example of the s-parameters you are using along with your calculated values of u & e to pbartley@innovativemeasurements.com.

While there are plenty of dielectric materials with known properties I have not seen magnetic material with standard properties over some frequency range.