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Rf Mems

  1. Jun 18, 2007 #1
    Hello, can any tell website where i can find Permittivity,Permeability and conductivity(or resistivity) of silicon, silicon nitride and aluminum.thanks
    and also if any one has worked in ELECTROMAGNETIC module of Intellisite (version 8.1)for RF MEMS Switches plz do tell me i need some guide line.
  2. jcsd
  3. Jun 18, 2007 #2


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    The relative permeability of most materials that do not
    contain any ferromagnetic atoms is very close to 1.0,
    and the RF permeability is generally less than the DC value
    for most materials. All of the materials you mentioned are
    non-magnetic so the permeability will be about the same
    and very close to 1.0 relative.

    You say this is for *RF* MEMS; you will find with many
    materials that the properties of Permittivity, Permeability,
    and Conductivity vary with frequency, as well as with the
    particular microstructure of the material.

    Therefore values of those parameters specified at a
    given frequency may not be as accurate as necessary at
    a different frequency of interest. Often one can find the
    values for DC, low frequencies in the 10-100kHz or 1MHz
    range, then perhaps values taken at 1GHz and perhaps at
    optical frequencies.

    You may have to interpolate various data tables to estimate
    the values at your particular frequencies.

    Also for RF frqeuencies especially those in excess of
    several hundred MHz, you'll find that parameters such
    as the following can effect the conductivity and permittivity
    -- the material's crystal / grain structure, porosity, purity,
    surface roughness, substrate or overcoat layer effects, et.

    Aluminium, speficically, comes in many alloys and those
    influence its nanostructure and microwave conductivity
    somewhat, though in general the materials used for
    high speed IC foundty applications may be expected to
    yield relatively smooth metallized layers with relatively
    good conductivity. Check various four-point-probe
    measurements of various thicknesses of wafer
    Aluminization layers for resistivity information beyond
    what is available in the tables below if that's relevant to you.

    Check the following sources for some parameters:
    The "CRC Handbook of Chemistry and Physics".
    et. al.
  4. Jun 18, 2007 #3


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    P.S. the conductivity for silicon is hugely dependent
    on doping and purity, which is why silicon semiconductors
    work as circuit elements. Intrinsic undoped very pure
    silicon has fairly little conductivity at low to moderate
    temperatures. Once you inject some free charge carriers
    into it and temperature or excitation or doping lowers the
    band-gap then it can be quite conductive. The range of
    conductivity is easily thousands to one depending on the
    material processing.
  5. Jun 19, 2007 #4
    Thanks a lot Xez for such a detailed reply.It will of gr8 help 2 me.Also if u have any other important info in the field of RF MEMS Switches plz do share it with me e.g important properties required for dielectric material to be used in RF MEMS Switches
  6. Feb 4, 2009 #5
    hi can anyone tell me whether it is possible to get the license file alone of intellisuite 8.53 version in net. if so please help me to get that crack file. i got the software from my friend but the license file is expired already.Even it will be good if i get the software for other versions which i can download. Also help me to get some materials for RF MEMS Capacitive Shunt switch since iam doing a project on it.
  7. Feb 5, 2009 #6
    Hi ayeshaa
    Hi xez
    I hereby give more explanation for the thermal conductivity of silicon rubber material.
    commonly the thermal conductive produts that is a combination of silicone rubber (Organic siloxane polymer), thermally conductive stuffing and flame retardants.
    Many thermal materials have been used in industy to cool the components for many yease!it's really convenient for us to use this material !
    any problem, please feel free to contact me, i am glad to discuss it with you
  8. Feb 15, 2009 #7
    please tell me the difference between a mems switch and a mems filter
  9. Mar 27, 2010 #8
    Can anyone send me a program for rf mems filters in either in matlab or c....
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