On Thu, 4 Aug 2005 11:51:07 -0500, (Richard
Harrison) wrote:

Richard Clark wrote:
"Well, given the tremendous correspondence that attended the other
threads, dare I pause to offer something from the realm of the real?"

If you don`t want an EM reflection in space, the possible reflecting
object must be indistinguishable from space. It must have a resistive
characteristic impedance of 377 ohms.

Hi Richard,

This was EXACTLY the design goal obtained by NREL with their diffusion
of a gradient of pores through the depth of the active surface. The
variation of the index of refraction went from 1.0 to 3.5 with a
smooth curve (albeit one jag at the beginning which reflects - seems
only armchair designers can do it right).

377 ohms per square material spaced 1/4-wave from a reflective surface
for the purpose of completely absorbing a normally incident wave was
invented by Stanfield Salisbury at the Harvard Radio Research Laboratory
during WW-2

And this is roughly the technique employed by diffraction techniques
which are superior to the quarterwave designs. The purpose is to
contain the energy within the active matrix.

It appears your news server truncates the Topic line, starting a new
thread each time - at least on my reader, I've noted that Google sews
the threads back together tho'.

73's
Richard Clark, KB7QHC