In article . com,
" wrote:

Since the antenna is a vertical, I thought that the best low-angle
radiation is 5/8 wave for verticals, anything longer would put the
lobes higher and would result in a lower low angle gain.

If this is the case then the antenna should only be about 3.5 inches
long. ?

PD-

The beauty of the 5/8 (0.625) wavelength groundplane antenna, is that its
feedpoint impedance has a resistive component of 50 Ohms, and can easily
be matched with a small inductor. Some such antennas have been
constructed by winding the coil using the base of the antenna rod. It is
my recollection from an antennas class 35 years ago, that the best signal
towards the horizon comes from a 0.58 wavelength groundplane antenna, not
0.625 wavelength. I can see how 5/8 and 0.58 might be confused, and many
may consider the difference trivial.

As far as the D-Link antenna, it is most likely a co-axially fed vertical
dipole with additional colinear elements separated by phasing networks.

Fred