Abstract—In this paper, a novel antenna for UHF RFID tag
with circular polarization is proposed. The antenna is
comprised of two diagonal dipoles with unequal slots to
produce circularly polarized (CP) radiation and a simple
tunable matching network. The measured result for power
reflection coefficient (PRC) is 35 MHz (894-929 MHz) and its
corresponding simulated 3-dB axial-ratio (AR) bandwidth is
about 31 MHz (903-934 MHz). The overall antenna size is
at 915 MHz and the maximum
simulated gain is about -2.8 dB. The experimental results
verify a perfectly RHCP radiation.