A compact wideband circularly polarized quadrifilar antenna with PIFA elements for UHF RFID readers
Chawanat Lerkbangplad, Alongkorn Namahoot, Prayoot Akkaraekthalin, Suramate Chalermwisutkul
In this paper, a compact circularly polarized quadrifilar antenna with planar inverted-F antenna (PIFA) elements is presented. The proposed antenna consists of four PIFA elements and a Wilkinson divider-based feed network fabricated on FR-4 substrate ( = 4.4, loss tangent = 0.02, thickness = 1.6 mm). The total size of the antenna is 120 × 120 × 13.2 mm. Impedance matching with a reflection coeffic