Owen Duffy wrote:
On Fri, 09 Dec 2005 13:06:17 GMT, "Frank"
wrote:


"Owen Duffy" wrote in message
. ..

On Thu, 8 Dec 2005 21:44:07 +0000 (UTC), "Reg Edwards"
wrote:


I have been informed my GRNDWAV3 program is in error - it calculates
the power input to a matched receiver to be 6dB greater than it
ought........
..........resistance. Again choosing simple values -

An alternative is to calculate the power collected by a lossless,
matched receiver as Pr=S*A.

In this case, S=0.3**2/(120*pi)

Kraus derives A (the effective apperture) for a short dipole to be
3/8/pi*wavelength**2.

This gives the power collected by the receiver as 6.4mW. If the
antenna and receiver were disected by the ground plane, wouldn't there
be 3.2mW developed in each half of the receiver load?

Owen

Then S = 2.387*10**(-4) W/m**2;

and A = 0.119*(Lambda)**2, where Lambda = 20m. (p.44)


I thought Reg was talking about f=20E6, so Lambda~=15m isn't it?


Therefore A = 47.6 m**2;

and Pr = 11.36 mW.

Since we have done this modeling of incident E-fields before, should there
not be some correlation with NEC2?

Frank

PS, your FORTRAN notation threw me for a second.


Several languages use ** as the exponentiation operator, FORTRAN was
probably the first. C, the C-like languages and IIRC most of the Algol
languages use **. The ^ operator used in VBA is a logical operator in
most languages.

Owen
--

It's been a while since you've done mathematical stuff in C, hasn't it?

C does _not_ use a '**' operator. If you want to raise y to the x power
you use "pow(y, x)".

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com