The J-pole antenna is a wire antenna with a form that resembles the letter "J" and performance similar to that of a wire dipole antenna. In its most basic form it is defined as a half wavelength antenna with a quarter wavelength matching stub. Similar to a dipole, the J-pole has an omnidirectional radiation pattern. It is sometimes referred to as an end-fed Zepp; a reference to the antennas used on the Zeppelin dirigibles in the 1930's. The Super J-pole is an extension of the J-pole antenna. The addition of a half-wavelength radiating section on top of the J-Pole antenna, increases the original gain by approximately 2 dB, and brings rise to the "Super" J-Pole.
The Super J-pole has a fairly narrow impedance bandwidth, ranging from 3.7% to 6.6%. The radiation pattern is similar to that of a dipole, with slightly more gain and small asymmetry about the azimuth....Typical total 3D radiation pattern at the center frequency. Typical S11 performance of the antenna.