Roy Lewallen wrote:
Jim Lux wrote:
Tom Donaly wrote:
Finally, a modest question: if you have EZNEC, why would you
be wasting time with something inferior? The gold standard is the gold
standard.
Perhaps more the silver or electrum standard.
EZNEC doesn't do dielectric loading, for instance. (unless you get the
Nec4 engine from Roy)

All program types, including the demo, of EZNEC v. 4.0 and later do
dielectric loading similar to NEC-4. (The method came from sources other
than NEC-4.) Like the NEC-4 implementation, it's of limited accuracy and
usefulness -- it's really good only for thin wire insulation of moderate
permittivity.

I stand corrected. Thanks.


And, it's a MoM code, so things not well represented by collections of
wires aren't necessarily modeled well.

Absolutely true. And it can't handle things like patch antennas or
antennas printed on a PCB.

NEC does OK at microstrip patches with air dielectric (or foam with very
low permittivity). I've used it to model an array of 9 patches and the
port to port coupling calculated by NEC and measured by a VNA were
pretty close (within measurement uncertainty).

It's pretty darn slow at this, though (lots and lots of wires in each
patch), I used lumped loads for the matching network model (capacitive
probe feed)