Frequently Asked Questions On Antenna Theory With Answers -16.


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


76) What is meant by Space Wave?

It is made up of direct wave and ground reflected wave. Also includes the portion of energy received as a result of diffraction around the earth surface and the reflection from the upper atmosphere.


77) What is meant by Surface Wave?

Wave that is guided along the earth’ s surface like an EM wave is guided by a transmission is called surface wave. Attenuation of this wave is directly affected by the constant of earth along which it travels.


78) What is meant by fading?

Fading is variation of signal strength occur on line of sight paths as a result of the atmospheric conditions. It can not be predicted properly.


79) What are the type of fading?

Two types:
  • Inverse fading.
  • Multi path fading.


80) What is inverse and multi path fading?

Inverse bending may transform line of sight path into an obstructed one.

Multi path fading is caused by interference between the direct and ground reflected waves as well as interference between two are more paths in the atmosphere.



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