Single-Feed, Wideband, Circularly Polarized, Crossed Bowtie Dipole Antenna for Global Navigation Satellite Systems

摘要

A wideband circularly polarized (CP) antenna with a single feed is proposed for use in global navigation satellite systems. Its primary radiation elements are composed of two orthogonal bowtie dipoles, which are equipped with double-printed vacant-quarter rings to allow direct matching of the antenna to a single $50-{Omega}$ coaxial line and to produce CP radiation. The crossed bowtie dipole is appropriately incorporated with a planar metallic reflector to produce the desired unidirectional radiation pattern as well as to achieve a wideband characteristic in terms of impedance matching and axial ratio (AR) bandwidths. The designed antenna was fabricated and measured. The prototype antenna with an overall 1.2-GHz frequency size of $0.48{lambda}_o{times}0.48{lambda}_o{times}0.25{lambda}_o$ produced a measured ${mid}S_{11}{mid}$${pm}0.3dB$) and high radiation efficiency (>93%) over the operational bandwidth.