I am simulating on EZNEC an antenna yielding a gain of about 13.5 dB (at zero
deg. elevation) when in free space.

The same antenna, placed on an ideal ground, shows a gain of about 18.8 dB (at
10 deg. elevation), thanks to the so-called "ground gain".

If the antenna is placed on a non-ideal ground (according to EZNEC modelling),
its gain becomes 18.4 dB.

I am surprised of the small gain difference between the ideal ground case and
the non-ideal ground case (just 0.4 dB). As a matter of fact, while the ideal
ground may be regarded as a perfectly conductive plane, the non-ideal ground is
something having a significant ohmic resistance. I would had thought that most
of the RF power incident on a plane having a significant resistance would be
absorbed (and hence not reflected).

Any comment please?

73

Tony I0JX