Module 7 : Antenna
Lecture 48 : Hertz Dipole Antenna

                                                           
                                               Vector potential due to the Hertz dipole

The vector potential due to the Hertz dipole is therefore given as
 
Note that the magnetic vector potential is in the z-direction and it has same direction every where in the space.
   

Since the coordinate system used for the antenna analysis is spherical, the components of the magnetic vector potential in spherical coordinates are

 
 
 
                                                                                            
   
 

Fields due to the Hertz Dipole

   

The vector magnetic field is

   
 
 

The magnetic field components can be obtained as

 
 
 
                                                
 
The Hertz component has only -component. That is, the magnetic field loops around the z-axis.
 

Substituting for H in the source-free Maxwell's curl equation the electric field can be obtained as

 
 

The -component of the electric field is zero.

 
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