NEC-LIST: How to model finite-size rectangular ground plane?

I am just learning to use NEC codes to calculate a 1/4 wavelength
monopole over a small( about 1/6 wavelength ) rectangular metal box.
I found out that GN card seems only allow a finite circular ground
plane to be defined. For example:

GN 0 0 0 0 1.00E+00 -3.70E-07 1.00E+00 0.00E+00 1.00E+00

I suppose it is for a finite conductivity circular plane with radius
of 1 m and (eps_c = 1.0 - j 3.7e-7). Is there any way we can model a
rectangular ground plane? Or I did not comprehend the user manual
correctly?

Thanks for any enlightenment.

Puck
Received on Mon Apr 17 2000 - 15:25:21 EDT