Material Measurement Software: does anyone have one?

[amexist]

Hello,

I am doing material measurements for my research on microwave absorption in certain materials. I wrote my own code in Matlab to convert s-parameters into permittivity and permeability, however I get some strange output for certain frequencies.

I know that there are professional software solutions, like "Agilent 85071E
Materials Measurement Software". However, we are not considering buying one at this time, since it is expensive.

I am wondering if anyone here already has this kind of software and would be willing to run it with the s-parameter data I have and can send you over email. That would help me in figuring out if my algorithm is working or not.

If don't have it, but you can refer me to someone who might have it, I would appreciate it a lot.

Thank you.

 

[jgruszynski]

First: s-parameters are linear model parameters. Many materials have non-linear dc or ac bias dependencies. E.g. if your stimulus power is too high and you have such non-linearities, you'll get strange s-parameter values that aren't real.

Second: I guessing your extraction is for a simple linear permittivity and/or permeability model. Real materials are often complex polynomial functions of bias and frequency. This can cause odd results.

Third: a bad calibration on a NWA can easily cause non-physical s-parameters and derived values will be bizarre.

All of these also occur when you use an LF LCR meter to measure impedance and derived values like capacitance, inductance and resistance, or permittivity and/or permeability.

 

[amexist]

jgruszynski: Thanks for your feedback.
My extraction technique is based on the Nicolson-Ross-Wier model (its short description can be found, for example, http://mars.mines.edu/diaperm/system.htm). The method does have the phase ambiguity and that might cause problems, though almost almost every paper on microwave properties of materials uses this technique.

In our research, calibration might be an issue at higher frequencies due to the old calkit. However, for example, s-parameters of a pure paraffin sample look very reasonable throughout the region (1-17GHz) compared to the data obtained from the simulated coaxial measurements in ADS. I believe it is my software implementation of the algorithms that for some reason does not produce a relatively flat line for a dielectric constant as it has been shown theoretically and experimentally.

Thanks for you help.

 

[Rodeoman]

Hello,

I am doing material measurements for my research on microwave absorption in certain materials. I wrote my own code in Matlab to convert s-parameters into permittivity and permeability, however I get some strange output for certain frequencies.

I know that there are professional software solutions, like "Agilent 85071E
Materials Measurement Software". However, we are not considering buying one at this time, since it is expensive.

I am wondering if anyone here already has this kind of software and would be willing to run it with the s-parameter data I have and can send you over email. That would help me in figuring out if my algorithm is working or not.

If don't have it, but you can refer me to someone who might have it, I would appreciate it a lot.

Thank you.

Dear Amexist,
I'm too trying to write a similar Matlab code, like yours, so I'd be pretty grateful to you, if you sent me yours, cuz I'm not all that much in Matlab.
Thanx alot in advance
Rodeoman;-)