Planar inverted F antenna circularly polarized for RFID applications

This article presents a new miniature antenna for UHF RFID reader. Circular polarization and size reduction (70% than a classical patch) of the radiating element are achieved by using a single probe feed and two short circuits. The measured axial ratio bandwidth obtained with the proposed antenna is about 270 MHz (28.2%). This antenna has a total volume of 250 mm × 250 mm × 19 mm.