Antennas.....

bountyhunter said:

... and the problem is they behave differently for no reason anybody can understand.

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This is the part I don't agree with, and I challenge you to offer any authoritative soure for this assertion. I don't think you can find one.

Antennas work fine in free space, a lot easier to model too.

But the real world is not free space. Surrounding objects modify the near field, and almost always a final design needs to be built and tested several times to get the optimum results from it.

An antenna does not need to be tuned to a resonant length, but most are.
Quite simply, resonance creates a build-up of energy that greatly increases the voltages and currents in the radiating portion of your antenna. It is essentially something for nothing and greatly improves the efficiency.

Papabravo said:

This is the part I don't agree with, and I challenge you to offer any authoritative soure for this assertion. I don't think you can find one.

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OK, I;ll waste one more post. BTW, here is what I said:

electromagnetic fields are hardly that easy to model and the problem is they behave differently for no reason anybody can understand

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You want an authoritative source? How about commion sense? Why is it we have to divide wave theory into "near field", far field", "fraunhoffer region", etc... after all, according to you, "waves are just waves".

If you were correct, there should be no problem coming up with a simple equation or formula to define the behavior of "waves", and we shouldn't have to worry about "regions".

Got one?

That's what I thought you said.

hence my point is proved that waves behave very differently in different environments and noboy knows exactly why, at least they don't understand it well enough to say why they have to be so different and why we can't understand the whole picture. Think it's simple? Step up and do it, there's a Nobel Prize in Physics just waiting for you if you do.

Warpspeed said:

Antennas work fine in free space, a lot easier to model too.

But the real world is not free space. Surrounding objects modify the near field, and almost always a final design needs to be built and tested several times to get the optimum results from it.

Click to expand...

Spoken like an old dinosaur like me..... all the kids these days think models have all the answers and only go into the lab as a last resort.

back when I was in school, antenna experts built them, tweaked them, then sat down and tried to figure out why they worked.

bountyhunter said:

Spoken like an old dinosaur like me..... all the kids these days think models have all the answers and only go into the lab as a last resort.

back when I was in school, antenna experts built them, tweaked them, then sat down and tried to figure out why they worked.

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Yes indeed Bountyhunter, well said.