Directional UHF near-field RFID reader antenna with an improved magnetic field distribution

In this paper, a directional ultra-high frequency (UHF) near-field radio frequency identification (RFID) reader antenna is designed with an improved magnetic field distribution. Utilizing a high impedance surface (HIS) as a reflector, the proposed segmented grid-loop antenna shows a significant improvement compared with the benchmark example in terms of a more evenly distributed and stronger magnetic field.