Wideband circularly polarized antenna for GNSS applications

A circularly polarized (CP) antenna with a wideband characteristic is proposed for use in the Global Navigation Satellite System. Its primary radiation element is crossed bowtie dipoles, which are incorporated with double-printed vacant-quarter rings to allow the antenna to be matched directly to a single 50-Ω coaxial line and produce wideband CP radiation. The radiator is backed by a planar metallic reflector to achieve a desired unidirectional radiation pattern. The final design, with overall sizes of 0.48 λ₀ × 0.48 λ₀ × 0.25 λ₀ at 1.2 GHz, resulted in a |S11| <; -10 dB bandwidth of 1.05-1.79 GHz and a 3-dB AR bandwidth of 1.12-1.64 GHz. Additionally, it showed right-hand CP radiation with a small gain variation (±0.3 dB) and high radiation efficiency (>93%) within its operational bandwidth.