Different between Axial mode and normal mode helical antenna

Hi anyone can guide me if there is any different in the parameters of normal
and axial mode helical antenna other than the different in radiation pattern?

Normal mode :
The spacing and diameter of the antenna are very small compared to the wavelength.
In this mode the helix radiates broadside - linearily polarized like a linear dipole.

Axial mode :

The spacing between the loops (height between each loop) and diameter are in the order of the wavelength or large fractions of it.

You'll achieve circular polarized endfire radiation.

P.