1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Electric far field for an arbitrary current through arbitrary antenna

  1. Nov 17, 2013 #1
    If we consider an arbitrary time varying current [itex]I\left(t\right)[/itex] flowing through an arbitrary antenna, then is the following a plausible expression for the electric field [itex]\vec{\mathrm{E}}\left(\vec{\mathrm{r}},t\right)
    [/itex] in the far field region:
    [itex]
    \displaystyle\vec{\mathrm{E}}\left(\vec{\mathrm{r}},t\right)
    = \frac{1}{4\pi \epsilon_0 c^2 r} \;
    \sum_{i=1}^{n}
    \left[
    \vec{\mathrm{a}}_i\left(\hat{\mathrm{r}}\right) \;
    \frac {d^i}{dt^i}I\left(t - \frac {r} {c}\right)
    \right]
    [/itex]​
    where the integer value [itex]n[/itex] and all vector functions [itex]\vec{\mathrm{a}}_i\left(\hat{\mathrm{r}}\right)[/itex] depend only on the antenna geometry (i.e. not on any characteristic of the input excitation), and [itex]
    \vec{\mathrm{a}}_i\left(\hat{\mathrm{r}}\right)
    \cdot
    \hat{\mathrm{r}} = 0
    [/itex] for all [itex]i[/itex]?

    And if this can indeed be done, what kind of expression can be deduced when the same antenna is receiving radiation -- converting the electric field into a current or voltage?

    I am trying to understand if it is possible to characterize an arbitrary arrangement of conductors as an antenna purely in the time domain -- as opposed to parameters like radiation resistance, gain, antenna aperture and radiation pattern that depend on frequency/wavelength.

    Thanks...
     
  2. jcsd
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted



Similar Discussions: Electric far field for an arbitrary current through arbitrary antenna
  1. Arbitrary potentials (Replies: 2)

Loading...