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changed title; retagged; typos;
Qmechanic
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Near-field around parabolic antenna?

Having a discussion at work about the $H$-field around a big parabolic antenna.

All of the safety tests done around the antenna only mention $E$-Field. They state in the radiating near-field the $E$ and $H$ are related so no need to measure them both. On the other hand all of the wire antenna have $H$-field included in their measurments.

I would have thought this was the wrong way around. Simple wire antenna have near-fields extending only a couple of wavelength but paraboic near-field can extend to a few $km$.

Only thing I can think of is that the near-field definition only applies to the front of the antenna - the back and surrounds are shielded by the parabola.

Is there a $H$-field, independent of the $E$-field in the immediate vicinity of a parabolic antenna?

Matt
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