Configuration
In the most basic form, a quarter-wavelength section of coaxial cable is prepared such that the inner and outer conductors are separate but still attached to the remaining cable.
The outer (sheath) conductor is connected to a quarter-wavelength conducting sleeve into which the cable is inserted, and the inner conductor protrudes vertically above the sleeve for a quarter-wavelength. Also, additional quarter-wavelength sections may be connected to outer conductor to form a better ground plane.
Read more about this topic: Coaxial Antenna