Hi Dario,

Thanks for the information on the permittivity factor allowing a
shorter antenna due to a shorter wavelength, and for pointing out the
array part for a longer monopole. I actually did quite a bit of
analysis on arrays in multiple dimensions but never thought a longer
antenna element would be equivalent to stacking up monopoles. So
thanks for pointing that out.

But part of the question remains, I guess then is how would be possible
to increase gain of a monopole without going over lambda/2, while
maintaining the dounut shape radiation pattern of a monopole.

Also, out of curiosity, why would any one wants to pay $200 for a 3 ft
long antenna vs $60 for a less than 1 ft long antenna of the same gain,
only because the $200 is an outdoor one?