Broadband circularly polarized tapered dipole antenna for GNSS applications

A broadband circularly polarized (CP) dipole antenna for global navigation satellite system (GNSS) is proposed. The antenna consists of a compact feed structure and four dipoles rotating in sequence. The series‐fed power splitter network is adopted in the feed structure to achieve a 90° phase shift and four equal power outputs. Tapered dipoles are applied to the radiator to increase the impedance bandwidth, while blade‐shaped parasitic patches are added next to each dipole to increase the axial ratio (AR) bandwidth. In order to increase the front‐to‐back ratio (FBR) of the antenna, a suitable circular hole is cut in the center of the reflector. Compared with the traditional reflector, the FBR is increased by about 5 dB on average in the whole band. The measurement results show that the impedance bandwidth with |S11|