Low-Profile Wideband Dual-Polarized Dipole Antenna With Parasitic Strips and Posts

A low profile +/- 45 degrees-polarized dipole antenna having an extremely wide bandwidth is proposed. Two crossed dipoles consisting of detached radiation arms are utilized as radiators and they are excited by dual simple striplines. Then several trapezoidal strips and four pairs of rectangular strips are utilized to improve the impedance matching over an exceedingly wide frequency band. For further improving the impedance and stabilizing the radiation pattern, four metallic posts are employed and located around the radiators. Another trapezoidal metal is finally added to the feed stripline of -45 degrees polarization to improve the input impedance for -45 degrees polarization. Our antenna has an extremely broad bandwidth of 80.4% (1.68-3.94 GHz) with VSWR < 1.5, isolation > 27 dB, and steady 3 dB beamwidth [half-power beamwidth (HPBW)] of 66 degrees +/- 8 degrees in the operating band. The antenna has compact size of 0.32 lambda(L) x 0.32 lambda(L) x 0.15 lambda(L), where lambda(L) represents the wavelength at the lowest frequency of the operating band.

Automated summary

This paper proposes a low profile +/- 45 degrees-polarized dipole antenna with an extremely wide bandwidth. Two crossed dipoles consisting of detached radiation arms are used as radiators, excited by dual simple striplines. Trapezoidal and rectangular strips are employed to improve the impedance matching, while metallic posts are utilized to further improve the impedance and stabilize the radiation pattern. The antenna achieves a bandwidth of 80.4% (1.68-3.94 GHz), VSWR < 1.5, isolation > 27 dB, and a steady 3 dB beamwidth of 66 degrees +/- 8 degrees in the operating band, with a compact size of 0.32 lambda(L) x 0.32 lambda(L) x 0.15 lambda(L) (lambda(L) represents the wavelength at the lowest frequency of the operating band).