High K material in High frequency

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Discussion Overview

The discussion revolves around the search for high dielectric constant materials (specifically those with a relative permittivity above 5000) that can function effectively at high frequencies (above 10 MHz). Participants explore the feasibility of using ceramics and other materials, as well as the implications of dielectric properties on electromagnetic fields.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant seeks a high K material to cancel out an E-field induced by electromagnetism, questioning the effectiveness of ceramics at high frequencies.
  • Another participant clarifies that "K" refers to the dielectric constant (relative permittivity) and asks for the units of the 5000 value.
  • A participant explains that a high dielectric constant material can influence the intensity of an electric field when oriented in a specific direction, but this claim is met with skepticism and requests for references.
  • There is a repeated inquiry about the existence of capacitors with relative permittivity above 5000 that can operate at frequencies above 10 MHz.
  • One participant notes that while a relative permittivity of around 5010 is achievable at 100 kHz, it is uncertain whether this holds true at higher frequencies, suggesting that relative permittivity may decrease with frequency due to increased conductivity.
  • A participant shares links to resources on capacitance versus frequency for different dielectrics and suggests considering an impedance analyzer for further characterization of materials.

Areas of Agreement / Disagreement

Participants express uncertainty regarding the availability and performance of high K materials at high frequencies, with no consensus reached on the effectiveness of ceramics or other materials in this context. Multiple competing views and questions remain unresolved.

Contextual Notes

Participants highlight limitations in existing knowledge about the behavior of dielectric materials at high frequencies, particularly regarding the relationship between frequency and relative permittivity.

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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  • #10
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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