Circularly polarized monopole slot antenna for UHF RFID reader
This article proposes a circularly polarized monopole slot antenna which is suitable for ultra high frequency (UHF) radio frequency identification (RFID) reader. In this antenna design, a meandering slot is being placed in the ground plane to produce good circularly polarized radiation characteristics, and the microstrip line feed can be adjusted to achieve good impedance matching. Measurement results showed that the 10 dB return loss bandwidth of the antenna is 10.3% (0.857 0.95 GHz) and the 3 dB axial ratio bandwidth of the antenna 7.4% (0.878 0.945 GHz) The maximum gain and efficiency of the antenna is 2.09 dBic and 76% respectively. The overall antenna size is 120 x 80 x 0.8 mm3. (c) 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:1102 1105, 2016