Antenna Theory - FAQ's With Answers - 2.


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


6) What are the different types of aperture?

  • Effective aperture.
  • Scattering aperture.
  • Loss aperture.
  • Collecting aperture.
  • Physical aperture.

7) Define different types of aperture?

Effective aperture (Ae):

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

Scattering aperture (As):

It is the ratio of the reradiated power to the power density of the incident wave.

Loss aperture (Ae):

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

Collecting aperture (Ae):

It is the addition of above three apertures.

Physical aperture (Ap):

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


8) Define Aperture efficiency?

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


9) What is meant by effective height?

The effective height h of an antenna is the parameter related to the aperture. It may be defined as the ratio of the induced voltage to the incident field.i.e H= V / E.


10) What are the field zones?

The fields around an antenna may be divided into two principal regions.
  • Near field zone (Fresnel zone)
  • Far field zone (Fraunhofer zone)


ALSO READ:


- What is meant by radiation pattern?

- Define Radiation intensity?

- Define Beam efficiency?

- Define Directivity?

- What is meant by Polarization?

- What is meant by front to back ratio?

- Define antenna efficiency?

- What is radiation resistance ?

- What is meant by antenna beam width?

- ...Return To Antenna Theory FAQ's Main Page.


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