A Compact Dual-Band GPS Antenna Design

This letter discusses a small slot-loaded, proximity-fed patch antenna designed for GPS operation at L1 (1575 MHz) and L2 (1227 MHz) bands. High-dielectric substrate and meandered slots are employed to reduce the antenna size down to 25.4 mm in diameter and 11.27 mm in thickness. The thickness is important for achieving the wide bandwidth (> 30 MHz) in support of modern GPS coding schemes. The dual-band coverage is achieved by utilizing the patch mode in L2 band and slot mode in L1 band. This design features additional slot stubs for independently tuning the L1 frequency. The right-hand circularly polarized (RHCP) field property is achieved by connecting two proximity probes to a small surface-mount 0 degrees-90 degrees hybrid chip. Simulated and measured antenna performance will be presented. This compact GPS antenna design is suitable for small GPS antenna arrays and portable GPS devices.