RFID tag antenna design and its EM simulation based measurement method

A UHF band inductively coupled loop feeding RFID tag antenna and its EM simulation based measurement method are proposed in this paper. A de-embedding method based on EM simulation is proposed for accurate RFID tag antenna measurement using coaxial line and SMA connector. The key dimensions of antenna and their effects on antenna's performance are studied. The measured result shows the antenna presents 100 MHz (880~ 980 MHz) bandwidth under the condition of voltage standing wave ratio less than 2(VSWR<;2) , and it agrees well with the simulated result. The proposed antenna presents 2dBi gain at the working frequency with dimension of 90mm × 16mm.