Re: NEC-LIST: Question about Average Gain calculation

The solid angle used in averaging is calculated as

Abs(dphi*(nphi-1)*(Cos(theta1)-Cos(theta2))

So it is correct if theta1 and theta2 are both positive or both
negative, but incorrect if one is positive and the other negative.
Also, if theta covers both negative and positive angles and the range
of phi is greater than 180 degrees it will sweep part of the sphere
twice.

Another caution to consider -- NEC-4 gives a wrong result for
radiated field over finitely conducting ground if theta is in the
range 270 to 360 degrees. NEC-2 just does not calculate anything in
that range. For a continuous vertical-plane cut you need to use
theta from -90 to +90, but not for average gain. For that you would
use theta from 0 to 90 and phi from 0 to 360.

Jerry Burke
LLNL

-- 
The NEC-List mailing list <nec-list_at_gweep.ca>
http://www.gweep.ca/mailman/listinfo.cgi/nec-list