Re: NEC-LIST:Multiple port excitation

Good day Wayne,

Whenever you are having trouble with silly results, it is best, if possible,
to start with the simplest possible model of your problem. Below is a very
simple crossed-dipole model qwhich behaves exactly as one would expect.
Note that the dipoles are half-wave, in free space, and cross at the center
with a 0.01 m separation. They are excited with sources in quadrature. The
resulting currents are in quadrature, and there is no interaction between
the dipoles. You probably have a more interesting environment, and a
diffferent orientation. You may be using drooping dipoles, in which case
there might be some interaction. In any case, start with something simple,
check that you have reasonable input impedances and quadrature currents, and
then add complexity.

Since you are trying to get a conjugate match at each port, I would suggest
that you drive both ports and monitor both input impedances as you make
changes. If you are getting interaction between the antennas, you must have
an asymmetry in your structure.

Doug Miron

CM CROSSED DIPOLES.
CE
GW 1 9 -0.25 0 0 0.25 0 0 0.001
GW 2 9 0 -0.25 0.01 0 0.25 0.01 0.001
GE 0
EX 0 1 5 1 1 0 1
EX 0 2 5 1 0 1 1
FR 0 1 0 0 300 0
PT -1
XQ
EN

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