Dual polarized cross bow tie dipole antenna having integrated airline

Abstract

A dual polarization antenna for transmitting/receiving polarized radio frequency signals includes a reflector plate that reflects the polarized radio frequency signals and one or more dipole assemblies. Each dipole assembly has two cross bow tie dipoles having radiating arms for transmitting/receiving the polarized radio frequency energy signals at two polarizations, and having U-shaped air-filled transmission feedlines for supporting respective radiating arms and providing the radio frequency signals between the reflector plate and the respective radiating arms. Each U-shaped air-filled transmission feedline includes two legs and respective feed rods arranged in respective legs. Each leg has a rectangular shape with three sides for isolating undesirable radio frequency energy. The radiating arms are triangularly-shaped and have notches dimensioned for minimizing radiation pattern distortion due to undesirable radio frequency coupling between the two cross bow tie dipoles. The dual polarization antenna also has an RF isolation device for coupling RF energy back in a proper phase and magnitude to cancel the undesirable RF energy of the respective opposite polarization. The RF isolation device includes an isolation tree or bar, isolation rails, small thin isolation rods or wires arranged in relation to the dipole assembly, or an isolation strip between positive and negative arms of the cross bow tie dipoles; or a combination of one or more of the above.