EENG463 ANTENNA THEORY PART 2 Hertzian Dipole (short dipole)

BY

PROF. DR. SENER UYSAL

SPRING 2014

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ANTENNA PATTERN PARAMETERS

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ANTENNA PATTERN DEFINITIONS

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• Isotropic antenna or isotropic radiator is a hypothetical (not physically realizable) concept, used as a useful reference to describe real antennas.

• Isotropic antenna radiates equally in all directions.

– Its radiation pattern is represented by a sphere whose center coincides with the location of the isotropic radiator.

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• It is considered to be a point in space with no dimensions and no mass.

This antenna cannot physically exist, but is useful as a theoretical model

for comparison with all other antennas.

• Most antennas' gains are measured with reference to an isotropic

radiator, and are rated in dBi (decibels with respect to an isotropic

radiator).

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ANTENNA POWER PATTERN ANALYSIS MAJOR STEPS

• TO BE ABLE TO CALCULATE THE TOTAL RADIATED POWER, WE NEED TO CALCULATE THE

AVERAGE POWER:

• TO CALCULATE THE AVERAGE POWER, WE NEED TO FIND E AND H VECTOR FIELDS:

• TO CALCULATE E WE NEED TO FIND H:

• TO FIND H WE NEED TO OBTAIN THE MAGNETIC VECTOR POTENTIAL:

• TO FIND THE MAGNETIC VECTOR POTENTIAL WE NEED TO KNOW THE CURRENT DISTRIBUTION:

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