(no subject)

> Does anyone know how NEC2 interprets a negative capacitance ??
>
>
>(I am using a series RLC loading card). Strangely, I am getting the results
>that I have been looking for, but with a disappointing negative capacitance.
>I tried taking their absolute values and then re-running NEC2, but the results
>are different. Any information on this subject would be greatly appreciated.
>
>Thanks alot,
>
> Jeff

A negative capacitance or inductance should be handled correctly in
NEC-2; at least in the current version here. If C is zero in a series
RLC it is treated as a short circuit rather than open, and in a parallel
RLC, L=0 or R=0 are treated as open rather than shorted. The tests for
"zero" values are done in subroutine LOAD. The load takes effect
IF(ABS(ZLR(ISTEP)).GT.1.E-20), the same for ZLI and ZLC for R, L, C,
respectively. You can check that the ABS() is used in your version of
NEC.

As a check you can put a RLC load on just the source segment of an
antenna. The impedance of the load should be added to the value
printed as input impedance.

Jerry Burke
LLNL
Received on Fri Aug 16 1996 - 05:39:00 EDT