Design and comparison between two general purpose dipole type UHF RFID tag antennas

Two short-dipole type RFID tags with diverse geometries have been developed to compare their performance with each other and with two commercial short-dipole type tags. Antenna structures were modelled with FEM-simulator to find a suitable geometries for matching and radiation properties. Based on simulation and measurement results bowtie design proved to be more apt geometry for an electrically small radiator and showed better performance compared to the other more traditional dipole type design. Comparison with two commercial tags showed that bowtie design has good impedance matching and also its backscattering properties were comparable with the commercial designs.