A Broadband Circularly Polarized Stacked Probe-Fed Patch Antenna for UHF RFID Applications

摘要

A broadband circularly polarized stacked probe-fedantenna suitable for UHF RFID applications is presented and studied. Theproposed antenna is fed by two probes which are connected to a hybrid coupler.Two parasitic patches are stacked above a primary probe-fed patch to enhance thebandwidth of the antenna. The optimized antenna prototype achieves gain of morethan 6.5?dBic, axial ratio of less than 3.0?dB, and return loss of less than?15?dBover the UHF band of 820–980?MHz (17.7%). Parametric studies are carried outto demonstrate the effects of antenna geometry parameters on the performance.The proposed antenna can be a good candidate for UHF RFID applications.