How to calculate aperture efficiency for an antenna with the following parameters:

  • Big reflector diameter= 24 mm
  • Gain= 9.265 dbi
  • Frequency= 11.60 GHz
  • 1
    $\begingroup$ 24mm? Did you mean cm? $\endgroup$ Oct 14, 2019 at 16:04

1 Answer 1


For any antenna, also for wire antennas, you can calculate so called effective area with $A_{eff} = \frac{\lambda^2}{(4\pi)}G$. An ideal antenna with surface area of $A_{eff}$ absorbs the same amount of power from the plane wave as that antenna. Aperture efficiency is defined as ratio of effective and physical surface area $\eta_{ap} = A_{eff}/A_{phys}$. For a circular reflector antenna the physical size is the area of your antenna facing the incoming plane wave $ A_{phys} = \pi(d/2)^2$.

  • $\begingroup$ Hi,Thank you, but what about Aphys(how I can calculate Aphys if I have the big reflector Diameter =24mm) $\endgroup$ Oct 14, 2019 at 8:42
  • $\begingroup$ I have edited my answer $\endgroup$
    – OH2FXN
    Oct 14, 2019 at 11:15
  • 4
    $\begingroup$ Are you sure about the input values? On a closer look it seems that your antenna diameter is barely a wavelength, not exactly a "big reflector" $\endgroup$
    – OH2FXN
    Oct 14, 2019 at 11:19
  • $\begingroup$ Antennas diameter is 26 mm,antennas height is 13.128 mm, gain is 9,265 dBi and frequency is 11.6 GHz. $\endgroup$ Oct 14, 2019 at 12:04
  • $\begingroup$ @KawaAbdoula to repeat what the others have said: a reflector that's not even one wavelength is not a "big reflector". It doesn't actually work well as reflector, at all. $\endgroup$ Oct 14, 2019 at 21:39

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