Understanding Material Measurements

[@christiand.3348]

Paul did it again! Fantastic job! Thank you for that.

[@olesia2004]

Thank you Paul! I like your English - very clear and easy to understand/

[@pauldenisowski]

My pleasure :)

[@krish2nasa]

Informative. Thank you very much.

[@pauldenisowski]

Thanks for watching!

[@能不能别放香菜]

Thank you so much! I can learn a lot from this ppt. There is one question: which measurement method is suitable for acquiring the permittivity of hydrogel? The hydrogel is a network of cross-linked hydrophilic building blocks surrounded by water. So I don't know which one is the suitable measurement methods. I'm looking forward to hearing from you soon.

[@pauldenisowski]

Hmm ... probably an immersed coaxial probe, but that would depend on the arrangement of the blocks and water (i.e. sounds like the material isn't uniform). Cavity might be another option, but I would also want to be sure the material under test was as uniform as possible.

[@Donquixote-qv7sp]

Don't steal the technology now

[@donnymac575]

Wow! I didn't realize a VNA could be used in this way.

[@jaggerimmanuel5927]

You probably dont give a shit but if you're bored like me atm then you can stream all of the new movies and series on instaflixxer. I've been streaming with my girlfriend during the lockdown xD

[@travismichael3705]

@Jagger Immanuel definitely, been watching on InstaFlixxer for months myself :D

[@ajingolk7716]

So how to test for aborbance and reflectance of microwave by materials?

[@mohithkumar3522]

why does resonant cavity method does not require calibration step?

[@pauldenisowski]

In the resonant cavity method, the resonant frequency and quality factor of the empty cavity are measured, then the measurement is repeated with the MUT in the cavity (see slide 17). Whether or not the measurement of the empty cavity is a "calibration" depends on how one defines "calibration" :) Typically in the VNA world, calibration is performed using standards with well-known properties (short, open, through, match, etc.). The T/R and OCP methods have "calibration" that most closely approximates traditional VNA measurements in that they require one or more calibration standards. In the free-space method and in the resonant cavity method, the calibration "standard" is really the absence of a standard (empty fixture vs. fixture with MUT). So we could divide these four methods into two groups: the T/R and OCP methods require "calibration" using a standard of some kind whereas the free-space and resonant-cavity methods require an initial "measurement" of the empty fixture (i.e. no cal standard needed). If we say that the resonant cavity method does not require "calibration", then this definition would also apply to the free space method as well.

[@mohithkumar3522]

Thank you for the response, but you still didn’t answer my question or I have not understood what you have commented. I know the procedure of resonance cavity method, and calibration to these methods is not required. I know one reason as resonant frequency are not affected and only dynamic range is altered. Do u have any other points to add

[@abidraza6373]

Calculation regarding open ended Coaxial Probe method please

[@pauldenisowski]

I would probably refer you to the whitepaper linked in the video description: a bit too much math to type in a KZbin comment :)

[@softwaremutyalu7441]

i need this ppt

[@gjrt7573]

there is a bird in the back ground.