High-Directivity and Circularly Polarized Compact Patch Antenna for UHF RFID Reader Devices

Abstract

This paper presents the design, construction, and testing of a high directivity and circularly polarized small patch antenna for the RFID Base Stations (Readers) operating in the European UHF RFID band. The designed and optimized patch antenna structure has a 15cm ×15 cm × 0.6 cm compact size where the -3dB beam angle is reduced by using slotted ring embedded in the patch. The gain of the antenna at 862 MHz is 3.2 dBic with the E and H plain beam angle are 61.6º and 65.2º respectively. Finally, the designed antenna is compared to a single-layer patch antenna of the same cross-sectional dimensions as the proposed antenna structure.