Dual-Broadband Dual-Polarized Folded Dipole Antenna With Stable Radiation Pattern

A dual-broadband folded dipole antenna with stable radiation performance and two polarizations is presented. To generate dual-polarized radiation performance within a wide frequency band, two pairs of folded dipoles are fed through slot lines and 50 Ω coaxial cables. To generate a notched band which is utilized to separate the wide working band of the folded dipole antenna into a low-frequency band and a high-frequency band, a cross-shaped strip is utilized and embedded upon the folded dipoles. To dramatically enhance the higher operating band, parasitic patches are extra-loaded above the cross-shaped strip. In the presented design, two wide frequency bands of 46.8% [(1.67 to 2.69) GHz] and 49.4% [(3.2 to 5.3) GHz] are realized. In addition, the measured gains and half-power beamwidths (HPBWs) remain stable within the range of 8.6 ± 0.7 dBi and 67 ± 5° in the lower band, as well as 9.1 ± 0.7 dBi and 69 ± 7° in the higher band.