NEC-LIST: Green's functions in NEC

Dear List,

I've been reading R E Collin's book on Antennas and Radiowave
Propagation
especially the bit about method of moments calculations.

It seems that the Green's function he quotes contains interactions
appropriate to the far field region, or radiation field region.
For example, the coupling strength falls off as 1/r.

Now it is my understanding that in the near field region, coupling
between antenna elements falls off faster than 1/r, and there is also
electrostatic and quasistatic magnetic coupling, as well as
radiation field coupling.

No doubt someone who reads this list and has written NEC code
can enlighten me as to why we can get away with a "radiation field
only" Green's function for interactions between adjacent bits
of an antenna structure.

regards

David Jefferies

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David Jefferies
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http://www.eryptick.net/
fax +44 (0)1483 534139 attn D.Jefferies
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