Abstract
A broadband circularly polarized stacked probe-fed
antenna suitable for UHF RFID applications is presented and studied. The
proposed 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 the
bandwidth of the antenna. The optimized antenna prototype achieves gain of more
than 6.5 dBic, axial ratio of less than 3.0 dB, and return loss of less than