Dual-band circularly polarized asymmetric dipole array antenna for GPS L1 and L2 bands

A dual-band, circularly polarized (CP) asymmetric dipole array antenna for Global Positioning System (GPS) applications with a wide beam is presented in this paper. The proposed antenna comprises two different-sized printed crossed dipoles with integrated baluns fed by an asymmetric feeding network to achieve dual-band functionality. Using two branch-line couplers with different dimensions in the feeding network performs Right-Hand Circular Polarization (RHCP) operation at GPS L1 and L2 bands. According to the experiments, the proposed antenna has wide impedance bandwidths of 24.82% (1139.5–1462.4 MHz) and 14.82% (1500.4–1740.5 MHz), and 3 dB Axial-Ratio (AR) bandwidth of 37.4% (1132.3–1653.2 MHz) to cover the GPS L1 and L2 bands. Furthermore, at 1227 MHz frequency, the antenna has a gain of 4.65 dBic, and a 3 dB AR beamwidth of 148.2° facing the sky. Also, at 1575 MHz frequency, a gain of 5.25 dBic and a 3 dB AR beamwidth of 139.3° are achieved.