A Circularly Polarized Antenna for Applications of GPS and DCS

In this paper, a small antenna for the applications of GPS and DCS systems by utilizing the CPW feeding structure is proposed to provide the LP and CP radiation patterns. The CPW feeding structure possesses the advantages, such as low radiation loss, less dissipation, uniplanar structure without the ground plane, and easy integration with RF/microwave circuits, enabling a miniature hybrid or monolithic microwave integrated circuit. The proposed antenna is particularly simple in manufacturing due to its single layer and no via hole required in shorting sleeve to the ground plane. The CP radiation is produced by properly adjusting the gap separation between the antenna and the sleeve strip. Both simulated and measured results are presented, which are in good agreement.