UHF near-field RFID reader antenna

A segmented loop antenna is presented for ultra high frequency (UHF) near-field radio frequency identification (RFID) applications. Even though the perimeter of the loop is comparable to the operating wavelength, the proposed segmented line configuration allows current along the loop to remain in phase so that a strong and uniform magnetic field is generated in the region surrounding the antenna. The antenna is printed on an FR4 printed circuit board (PCB) with an overall size of 160 mm × 180 mm × 0.5 mm. It achieves good impedance matching and uniform magnetic field distribution over an operating bandwidth of 800 - 1040 MHz which is desirable for UHF near-field RFID reader applications.