whip antenna coupling prediction

3/6/96

I would like to use NEC to determine the coupling between 2 30' whip
antennas on a small ship. I'm planning to model the ship using a wire
grid and then add some vertical segments for the whip antennas. I
will drive one of them with a unit voltage source at the base. For the other
antenna, I will insert an impedance (equal to the corresponding receiver's
input impedance) at the base and note the current into this "load" (to
determine received power).

I understand the NEC wire grid modeling guidelines and am not looking for
advice here. Rather, what I am questioning is whether the approach I have
outlined will give me accurate coupling information. I have heard that NEC
is not particularly good at estimating antenna input impedances and it
seems like I am trying to do something similar (i.e. I'll have to quantify
output power of the driven antenna as part of my coupling calculation which
will use the same current that is used to estimate antenna input impedances
and which has a tarnished reputation therein).

Does anyone know of a published validation study for a problem similar to
mine or have an alternate idea for computing coupling?

Thanks for any and all help.

Larry Gray (gray_at_engr05.comsys.rockwell.com)
Received on Wed Mar 06 1996 - 17:58:00 EST