A wideband circularly polarized antenna with wide half power beamwidth (HPBW) and 3 dB axial-ratio beamwidth (ARBW) is proposed in this paper. The circularly polarized (CP) radiation is realized by feeding two crossed printed dipoles through a wideband feeding network with broadband 90º phase shift. By adding a thick substrate layer and a notched-corner metal cavity around the antenna, the impedance bandwidth (VSWR < 2) is greatly enhanced. The HPBW of the proposed antenna are greater than 110º while the ARBW are greater than 130º in the operating band, simultaneously. The overall dimension of the antenna is only 70×70×36 mm3. The measured results show that the impedance bandwidth of the proposed antenna reaches 54.7% (1.06 GHz-1.86 GHz) while the AR bandwidth (AR<3 dB) is 48.6% (1.08 GHz-1.78 GHz). As such, the proposed antenna can be widely used in various global navigation satellite system (GNSS) applications.
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