Antenna Theory - What is Antenna Aperture & What Are It's Types?


This page contains basic questions and short notes on some of the keywords on antenna theory:


Aperture represents the area of the antenna confining the effective radiations.

The various types of antenna apertures are:
  • Effective aperture.
  • Scattering aperture.
  • Loss aperture.
  • Collecting aperture.
  • Physical aperture.


Effective aperture (Ae):

It is the area over which the power is extrated from the incident wave and delivered to the load is called effective aperture.

Scattering aperture (As):

It is the ratio of the re radiated power to the power density of the incident wave.

Loss aperture (Al):

It is the area of the antenna which dissipates power as heat.

Collecting aperture (Ac):

It is the addition of above three apertures.

Physical aperture (Ap):

This aperture is a measure of the physical size of the antenna.


The ratio of the effective aperture to the physical aperture is the aperture efficiency.
i.e.
Aperture efficiency = ηap = Ae / Ap (dimensionless).

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