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Homework Help: HPBW and FNBW of a antenna

  1. Apr 22, 2012 #1
    1. The problem statement, all variables and given/known data
    I am trying to learn how to read plots of radiation patterns and I am not stuck, but kinda not sure if I got it right.

    So I used we are using MEFISTo at our faculty to simulate this antenna, and we are given the task to identify some parameters.

    Some of them we need to find are
    HPBW in:

    XY plane, function of phi
    XZ plane, function of theta
    ZY plane, function of phi

    Same for the FNBW.

    Now I am busting my head for quite a while now, with imagining this radiation how it looks like, I think Im on the right track.

    Here is the XY plane, Cartesian coordinates.
    [PLAIN]http://pokit.org/get/img/eb81438a196ec41d4bbb08346fae6451.jpg [Broken]

    And polar:
    [PLAIN]http://pokit.org/get/img/235e6674014ec07fbe37243b4cfdaafc.jpg [Broken]

    From these 2 I concluded that HPBW is 90 degrees. Because, this is the plot of electric fields with respect to the angle and I am looking for the 0.707 value of the electric field.

    FNBW is 0 degrees.

    XZ plane:

    [PLAIN]http://pokit.org/get/img/6f2cb24e4f691f649170c8586bd044fd.jpg [Broken]

    And polar:
    http://pokit.org/get/img/7c57532d436bf76e1d8dd2472089542d.jpg [Broken]

    From these ones I concluded that the HPBW is 90 degrees again.

    FNBW is 180 degrees.

    And the YZ plane:




    We see that in this case, intensity is constant over all angles, which means HPBW is 360 degrees.
    2. Relevant equations
    3. The attempt at a solution
    Last edited by a moderator: May 5, 2017
  2. jcsd
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