Has anyone some experience with modelling antennas over
real ground, at low heigths?
For example:
I make a modell of a 20m Yagi in free space, resonant at 14,200 MHz.
It is a narrow band design. I let AO optimize the ant.
Now I put the ant over real ground at a low height, let's say at 5m
or 15 feet, 1/4 wave length.
Result: The pattern is changed because of the ground effects, as expected.
But I thought, the proximity of the elements to the ground will have a great
effect to the resonant freq of the elements and will make the ant misbehave.
Or in other words:
Is 1/4 wavelength high enough not to have any major influence on the
resonant
freq of the elements? Will modelling an ant at that low heigths give real
world
results?
73s
Chris DL4YAO
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