A　miniaturized　ultra-high　frequency　(UHF)　radio　frequency　identification　(RFID)　tag　antenna　was　designed.　The　antenna　was　composed　of　two　square　spiral　resonators　shorted　inside　and　outside.　By　adjusting　the　edge　length　of　the　outer　ring　spiral　resonator　and　the　spacing　between　the　inner　and　outer　ring　spiral　resonators,　the　resonant　frequency　of　the　proposed　tag　antenna　could　be　effectively　tuned.　The　simulation　results　show　that　the　proposed　tag　antenna　has　good　impedance　matching　and　the　frequency　band　range　covers　the　whole　UHF　band　(840～960　MHz).　It　has　a　dimension　of　7.60　mm×7.60　mm×0.05　mm,　which　is　96%　smaller　than　the　traditional　spiral　resonator　(SR)　antenna.　The　measure　result　shows　that　the　proposed　tag　antenna　achieves　the　maximum　reading　distance　at　910　MHz　in　4　W　effective　isotropic　radi-ated　power.　The　proposed　UHF　RFID　tag　antenna　has　some　advantages　of　small　size,　wide　frequency　band,　low　cost　and　easy　batch　fabrication,　and　is　suitable　for　applications　with　small　size　requirements.　©　2024,　Beijing　Xintong　Media　Co.,　Ltd.　All　rights　reserved.