Design of a novel meander line reader antenna for UHF near-field RFID

A novel reader antenna based on electromagnetic coupling between three meander open-ended microstrip lines for ultra-high-frequency (UHF) radio frequency identification (RFID) near-field applications is proposed in this paper. Meander line units are introduced to generate a strong uniform magnetic-field distribution over a large interrogation with no null zones. The antenna can be adapted to appropriate scenarios conveniently in practical application by increasing or decreasing the number of the meander line units. As an example, a 10-units meander line implemented onto a piece of FR4 printed board is designed and prototyped. The results show that the antenna achieved operating bandwidth about 14 MHz, which covered Chinese UHF RFID standard and produced uniform magnetic field distribution over an interrogation zone of 100 mm×750 mm. Both simulated and measured results are shown to illustrate the good performance of the proposed antenna.