High K material in High frequency

AI Thread Summary
A high dielectric constant material (above 5000) is sought for canceling E-fields at frequencies above 10 MHz, but there is uncertainty about the effectiveness of ceramics in this range. The discussion highlights the challenge of finding capacitors with such high relative permittivity at elevated frequencies, as typical materials tend to show decreased permittivity with increasing frequency. Suggestions include researching materials listed in relevant scientific literature and considering the use of impedance analyzers for accurate characterization. The conversation emphasizes the need for reliable references and practical solutions in material selection. Overall, the quest for suitable high K materials remains complex and requires further investigation.
Artyman
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Hello all
I need a high K material to cancel out E-field in some direction (induced by electromagnetism). This high K material (above 5000) must work in high frequencies above 10MHz. I did use the ceramics but there is no clue that it will work in that range of frequencies or not.
I am really stuck in this issue. I do not know can I use any meta-material or whatever for this performance or not.
thanks
 
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Artyman said:
K material (above 5000)
What's "K"? What units are on the 5000 value?
 
hi,
means high dielectric constant (epsilon r, relative permittivity above 5000) at high frequency
 
Artyman said:
I need a high K material to cancel out E-field in some direction (induced by electromagnetism)
How does a high dielectric constant material "cancel out" the E-field component of an EM wave?
 
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berkeman said:
How does a high dielectric constant material "cancel out" the E-field component of an EM wave?
When you place it in specific direction you can increase the intensity in one direction( for example: when there is two peaks in electric filed intensity)...!
 
Artyman said:
When you place it in specific direction you can increase the intensity in one direction( for example: when there is two peaks in electric filed intensity)...!
Sorry, that is not making sense so far. Can you provide a reference to what you are saying? A link or two to a description of this effect? That would help a lot...
 
berkeman said:
Sorry, that is not making sense so far. Can you provide a reference to what you are saying? A link or two to a description of this effect? That would help a lot...
Please forget E-field...
My problem : is there any capacitor( like ceramic one) can have relative permittivity (above 5000) at frequencies above 10 MHz?
 
Artyman said:
Please forget E-field...
My problem : is there any capacitor( like ceramic one) can have relative permittivity (above 5000) at frequencies above 10 MHz?
5000 is very high for relative permittivity, but you probably know that. Have you researched the materials near the bottom of the Wikipedia article's table that have high values of ε_r like that?

https://en.wikipedia.org/wiki/Relative_permittivity
 
berkeman said:
5000 is very high for relative permittivity, but you probably know that. Have you researched the materials near the bottom of the Wikipedia article's table that have high values of ε_r like that?

https://en.wikipedia.org/wiki/Relative_permittivity
We could get Relative Permitivity around 5010 for 100Khz. But, I do not know would it work for Higher frequencies or not. I searched a lot but in most cases as frequency increase the relative prmittivity decreases (I think due to increasing the conducting!)
 
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I did a Google search on capacitance versus frequency for different dielectrics, and got some good hits. Here is the hit list:

https://www.google.com/search?q=cap...y+for+different+dielectrics&ie=utf-8&oe=utf-8

This hit on the list looks promising::

http://www.sciencedirect.com/science/article/pii/S2211379716000310

Have you looked into renting or buying an impedance analyzer for your lab? If you are goint to be doing this type of characterisation more in the future, you could probably justify the costs based on what you are going to get out of the instrument. We use the HP 4194 Impedance Analyzer for these types of measurements in our lab:

https://www.google.com/search?q=hp+4194&ie=utf-8&oe=utf-8

http://literature.cdn.keysight.com/litweb/pdf/5952-7841.pdf?id=1319286

Hope that helps your work.
 
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