A Compact Broadband Circularly Polarized Antenna With Novel Tilt Fences for GNSS Applications

A compact broadband circularly polarized antenna with novel tilt fences for global navigation satellite system (GNSS) applications is proposed in this letter. The proposed antenna consists of Y-shaped feedlines with vacant-quarter rings, parasitic patches, ground, and novel tilt fences. Good impedance matching as well as circular polarization (CP) characteristics are achieved with novel tilt fences. New resonance modes and CP modes are introduced at low frequencies through novel tilt fences, which are equivalent to antenna miniaturization. The proposed antenna with four CP modes is fabricated using simple printed circuit board (PCB) technology and has a compact dimension of 0.29λ 0 ×0.29λ 0 ×0.18λ 0 (λ 0 is the wavelength of the center frequency). Based on the measured results, a wide impedance bandwidth (IBW) and axial-ratio bandwidth (ARBW) are achieved. The −15 dB IBW can cover 1.07-1.98 GHz, and the 3 dB ARBW is 61.5% from 1.07 to 2.02 GHz. In addition, the antenna has a wide overlap bandwidth of 1.07-1.98 GHz (59.7%). This simple and compact CP antenna has good potential in GNSS applications.