Dual-Band Circularly Polarized Antenna with Low Wide-Angle Axial-Ratio for Tri-Band GPS Applications

This paper presents the design of a dual-band microstrip antenna with low wide-angle axial-ratio. The antenna is designed for global positioning satellite operations at 1227 MHz(), 1575 MHz() and 1176 MHz(, available after 2007). This antenna has another advantage of a much wider band in both VSWR and 3 dB axial-ratio compared with single-fed GPS antennas. Details of the design, simulated and experimental results of this GPS antenna are presented and discussed. The measured results confirm the validity of this design, which meet the requirement of GPS applications.