A Srr-Based Near Field RFID Antenna

In this paper, a compact near field reader antenna is proposed for ultra-high frequency (UHF) radio frequency identification (RFID) applications. The antenna structure is composed of two split-ring-resonators (SRRs) and miniaturized to a special small size of 25 * 25 * 1:6mm3. The measured bandwidth of antenna prototype is 13 MHz (914.5-927.5 MHz) with reflection coefficient less than -10 dB, which covers the China RFID band II (920-925 MHz). Simulation shows that the proposed antenna achieves a strong and uniform magnetic field distribution in the near field region, and the reading range is up to 42 mm with near field RFID tag. Through modifying the parameters of SRRs, the antenna can operate on different UHF RFID bands (Europe band, China band I&II etc.).