Antenna Theory - FAQ's With Answers - 4.


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


16) What is meant by reciprocity Theorem?

If an e.m.f is applied to the terminals of an antenna no.1 and the current measured at the terminals of the another antenna no.2, then an equal current both in amplitude and phase will be obtained at the terminal of the antenna no.1 if the same emf is applied to the terminals of antenna no.2.


17) What is meant by isotropic radiator?

A isotropic radiator is a fictitious radiator and is defined as a radiator which radiates fields uniformly in all directions. It is also called as isotropic source or omni directional radiator or simply unipole.


18) Define gain?

The ratio of maximum radiation intensity in given direction to the maximum radiation intensity from a reference antenna produced in the same direction with same input power. i.e Maximum radiation intensity from test antenna (G)= Maximum radiation intensity from the reference antenna with same input power.


19) Define self impedance?

Self impedance of an antenna is defined as its input impedance with all other antennas are completely removed i.e away from it.


20) Define mutual impedance?

The presence of near by antenna no.2 induces a current in the antenna no.1 indicates that presence of antenna no.2 changes the impedance of the antenna no.1. This effect is called mutual coupling and results in mutual impedance.

ALSO READ:

- 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?

- What is meant by Beam Area?

- What is duality of antenna?

- State Poynting theorem?

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

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