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Antenna E and H filed

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baby_1

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Hello
what can we understand from each E and H plane alone?
The power pattern is not the most practical diagram? why do producers only report E and H plane diagram?

Thanks
 

hi,
E field is electrical field and H field is magnetic field. i would say most relevant gain and efficiency. from gain you got to know directivity and polarization of an antenna. from efficiency you know how much radiated power over input power for an antenna.

E field plus H field with other parameters involve creates force on charge/particle. from force we can get work done by moving a particle from a to b. maxwell have sub-divided the waves in detail upto electrical field and magnetic field...
 

Thank you dear pragash
could you tell me what you understand about this (for example)figures?
Capture1.PNG
 

E field and H field can be very different in the near field when very close to the antenna.

H field is basically magnetic, and will be highest around the resonant part of the antenna that carries the highest current.
E field is electrostatic charge and will be highest around the resonant part of the antenna that carries the highest voltage.

If you map these fields very close to the antenna, the field patterns will not be the same. Close is relative, depending on wavelength.

At a greater distance of many wavelengths, the whole thing merges into the impedance of free space and becomes more uniform. E and H lose their individuality and it just becomes a uniform electromagnetic wave front.
 
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hi baby,
i know exactly what you asking! i dont know if any antenna designers correct their antenna based on E field and H field results. lets see what others answering..
 

Thank you Warpspeed for your good explanation
Something is wondering me.As I know we obtain E and H filed of antennas in far-filed region and we draw them.So according to your explanation it means producers plot total E and H filed ( near and far filed)? In this diagram
Capture1.PNG
The red circles are near filed?

and what can we understand much more about these E and H filed diagrams?

Capture1.PNG
 

baby_1 said:
The red circles are near filed?
Click to expand...

No, at this graph there is no practical usage in a sub-circle representing the same radiation level, as you drew. By the way there are different patterns ocurring either at near or far fields. At too far distances, there's no significant change in the shape as we move away from the antenna. You might understand these curves as a relative ratio, comparing to the maximum gain versus the occurred at a specific direction.
 
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