Folded collinear dipole antenna

A Folded Collinear Dipole (FCD) Antenna comprising:

• first and second folded radiator elements having a length λ/2 corresponding to ½ wave of the frequency wave calculated wavelength and being separated along their parallel lengths by a distance D being approximately λ/40;
• a third radiator element having a length λ/2 having a lower portion and terminating at a lower end;
• a loading coil isolator having a length λ/5 that is coiled to define a set of coil turns with a diameter of λ/20 and being connected to one of the first and second folded radiator elements at a coil first end and connected to the third element at the opposite coil second end, thereby interconnecting the first and second folded radiator elements with the third radiator element;
• a bottom tube amplifier assembly configured to receive and support a lower portion of the third radiator element, the bottom tube amplifier assembly having a length λ/4 and comprising;
• an internal insulating sleeve made of Polytetrafluoroethylene (PTFE) having an RF reflective index of approximately 1.4;
• a brass ground tube shield configured to receive the internal insulating sleeve with an air gap formed between the brass ground tube shield and the internal insulating sleeve enhancing the signal velocity factor;
• an outer protective sleeve encasing the lower portion of the third radiator element, the internal insulating sleeve and the brass shield, and comprising environmentally stable and RF invisible material cross-linked polyethylene that is operationally invisible to the RF signal and avoids attenuating the RF signal;
• an RF fitting having a throat length and configured to receive the end of the third radiator element and wherein an end of the brass ground tube shield is securely affixed to a receiving portion of the RF fitting;
• and
• a tube seal cap disposed at the top of the bottom tube amplifier assembly opposite the RF fitting and defining an opening through which the lower portion of the third radiator element passes;
• wherein the bottom tube amplifier assembly is secured to the RF fitting and the throat length of the RF fitting is included in the overall length λ/4 of the bottom tube amplifier assembly.