Ultrawideband circularly polarized antenna with dual band-notched characteristics

This article presents an ultrawideband (UWB) crossed dipole antenna with circularly polarized (CP) and dual band-notched characteristics. The proposed design is based on two orthogonal tapered dipoles for UWB CP operation and a square-shaped cavity for high broadside gain over the entire operating bandwidth (BW). To generate dual band-notched characteristics, two separated slots are inserted into each dipole's arm. This antenna yields measured impedance BW of 100% (3.2-9.6 GHz) with dual-band rejection centered at 5.2 and 5.8 GHz. Correspondingly, dual rejected bands are also observed in the original UWB CP band, which ranges from 3.2 to 8.2 GHz. Additionally, the proposed antenna exhibits high broadside gains better than 6.2 dBic and radiation efficiency greater than 82%.