Broadband radio frequency identification reader-writer antenna with wide circularly polarized wave beam

The invention discloses a broadband radio frequency identification reader-writer antenna with a wide circularly polarized beam. The antenna comprises triangular defect radiation patches, a circular coupling patch, a grounding probe, a feed probe, a feed network, a dielectric plate, a metal floor, a coaxial connector and a short-circuit pin. According to the structure, the cross-shaped gap betweenthe triangular defect radiation patches is used for radiation to broaden the circularly polarized beam width of the antenna; the grounding probe effectively reduces the sizes of the triangular defectradiation patches; the impedance matching performance of the antenna is improved by the gap capacitance between the triangular defect radiation patches and the circular coupling patch; the introduction of the air layer improves the bandwidth of the antenna; the feed network based on the hybrid ring and the TRD coupler eliminates the mutual coupling influence between the triangular defect radiationpatches, and achieves good circular polarization performance.