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  1. Replies
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    Closed: Re: Focal fields of dish antenna

    Happy I was right !

    Thank you..
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    Closed: Re: Focal fields of dish antenna

    Thanks! It's very old story, now finished... this was not primarily satellite antenna, rather theoretical work on this topic.
    Anyway, I'm corrent you have articles in "Slaboproudy obzor"?
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    Closed: Re: Focal fields of dish antenna

    Thanks very much, that looks very reasonable! Just a remark - if we're not in far field then we have to use Fresnel transform, does the phase change significantly?

    E.
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    Closed: Focal fields of dish antenna

    Hello,

    I'm currently facing following problem:

    We have slightly disturbed offset dish, trying to find its focus.
    Dish's surface was scanned and physical optics was used to get E field in XY...
  5. Closed: Re: method of moment to calculate current distribution

    I probably didn't catch what you need exactly. In that code (+there exists nice book too) you'll find a lot of working examples, even showing current distribution on antennas
    best
    e
  6. Closed: Re: method of moment to calculate current distribution

    Hi, I got nice results with Makarov's code which could be freely obtained here:
    http://ece.wpi.edu/mom/

    Good luck :)
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    Closed: Re: a MoM question

    I finally made the theory working! :D
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    Closed: Re: Can CST MWS 2006 Work on Core Duo?

    I have also 2processor machine (2x Opteron).
    The load is usually around 60-70 percents for both processors. CST recommends to run 2 simulations together to utilize processors on 100%
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    Closed: Re: Can CST MWS 2006 Work on Core Duo?

    What's your service pack and what you mean by "wrong results"?

    Cheers
    e
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    Closed: Re: How to get broadband gain in CST MWS?

    There's no other way. Why it's not straightforward? I think it is..
    Of course it cost time, farfield is superposition of near field.
  11. Replies
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    Closed: Re: microstrip antenna gain range?

    Rect. patch working at fundamental mode has directivity ~ 8dBi.
    Simple estimation is following:

    - you have 2 magnetic dipoles at radiating edges (2dBi + 3 dB)
    - ground plane acts as mirror --> +...
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    Closed: what does cross pol mean?

    Dear Costox,

    Arrays arent my main interest but for most of my design Im happy with spherical and ludwig3. How the BW differs in your design?

    Please could you describe in details what you mean...
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    Closed: Re: How to get broadband gain in CST MWS?

    Hi, you mean this?

    Macros - Farfield - Broadband FF monitor
    ..
    Results - Template based postprocessing - Farfield (broadband)

    e
  14. Replies
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    Closed: co polarized antenna

    Polarization of antenna is given by E field distribution or electric currents (they produce E field in the same direction as the surface current dir.).
    Visualizing currents on ms patches is thus...
  15. Closed: IE3D - Dielectric cells and near field calculations

    Dear all,

    I was trying to calculate near E field of structure consisting of dipole illuminating lossy dielectric brick with high er.

    Result is very strange, the E field (cut inside the brick)...
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    Closed: Re: a MoM question

    Hi,

    matrix averaging is clever idea. Unfortunately, the results (eigenvalue behavior with frequency) are better for particular cases only and for few first eigenvalues only. In general, this...
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    Closed: Re: a MoM question

    Latest progress:

    I'm 99% sure that problem is in [Z] matrix symmetry. I've modified [Z] matrix to be symmetric using a little stupid trick - by mirroring the lower matrix triangle part over the...
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    Closed: Re: a MoM question

    Hello, Loucy,

    Part2 uploaded (sorry, forgot it)..

    Yes, I mean "Antenna and EM modeling with Matlab" codes as they are very powerful (importing meshes from FEMLAB) and easy to use in terms that...
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    Closed: Re: a MoM question

    Hello and thanks for your comments, friends!

    1) I can't prove my approach until the matrix [R] will be "healthy" for the theory, i.e. positive semidefinite (with all eigenvalues >=0) - as written...
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    Closed: Re: a MoM question

    Hello, Irfan

    Thanks for your interest! :)

    I'm quite sure that the matrix is OK. Studying the papers, I've got strong notion that the problem lies in real(Z) which should be positive...
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    Closed: Re: a MoM question

    Dear MoM professionals,

    I'm currently working to have "Theory of Characteristic Modes" running. Few papers on that are attached,
    it's also described a little in Harrington's book "Field...
  22. Closed: how an antenna radiates

    Hi!

    I'm usually using the attached picture.
    Imagine 2 E-field lines a-b, c-d (2 other arrows is the H field, but it's not important now).
    lines are travelling within the waveguide (for example 2...
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    Closed: Re: Near Field Region for Wire Antennas - ?

    Hi,

    there was a great paper on one of the latest AP-magazine (2-3 month ago), discussing near fields of wire antennas. Check it...

    If I remember, they were talking about much bigger distances...
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    Closed: Re: How to simulate a conformal antenna?

    "critical cells" warning means that conformal fit algorhitm wasn't be able to treat curved surface withing the cell. In result, given cell is now modelled as a "brick", like when classical staircase...
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    Closed: Re: Calculating Q of slot resonators

    Hi!

    What comes in my mind...
    The Q will be dominantly given by radiation Q (I think we can ommit dielectric losses - the slot is filled by air and conductor losses).
    Thus, what about to...
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