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What are the equations defining the near field of a half-wave dipole antenna? What is the rate of decay of E-field and H-field in the near field (both reactive and radiative zones)? How are the equations different from those for an Infinitesimal Dipole?

Infinitesimal Dipole E and H-field

Yasir Ahmed
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  • https://www.ahsystems.com/articles/primer%20on%20antenna%20near-field%20and%20far-field.php or, use Biot Savart law for the H field and equivalent for the E field. – Andy aka Dec 24 '21 at 15:24
  • @Andyaka are equations derived for infinitely small dipole applicable to half wave dipole...? – Yasir Ahmed Dec 24 '21 at 15:46
  • I have no idea. – Andy aka Dec 24 '21 at 15:56
  • I'm not sure the answer would be meaningful unless you were studying E&M up to the point where the book describes this -- and if you're at that point, the book gives the answer. What do you get when you do an Internet search on "Near field from a Dipole Antenna"? – TimWescott Dec 24 '21 at 18:42
  • If I remember well, equations are for a "short" dipole only, nearest dipole (terms with 1/r^2, 1/r^3), ( l << lambda). There are the result of the integration of formulas for an infinitesimal dipole antenna. – Antonio51 Dec 25 '21 at 12:11

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https://en.wikipedia.org/wiki/Near_and_far_field

According to the three regions, one can plot how the fields vanish with distance ...

enter image description here

Antonio51
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