Broadband single-fed single-patch circularly polarized antenna for UHF RFID applications

A broadband single-fed single-patch circularly polarized antenna for UHF RFID application has been presented in this paper. The simulated and measured results have shown desirable performance with the gain of ≫7 dBic, VSWR of ≪2, and AR of ≪3 dB within the frequency range of 0.84–0.935 GHz (10.7%). The antenna is also low cost due to the simple structure and no use of any dielectric substrate. Due to the broadband performance covering most of the UHF RFID band, this proposed antenna can be considered a versatile reader antenna considering its relatively good performance and low cost.