A Dual-Layer Broadband Compact UHF RFID Tag Antenna for Platform Tolerant Application

In this paper, we present a compact tag antenna for radio frequency identification (RFID) application. By embedding four parasitic planar inverted-F antennas under the top patch, four adjacent resonant modes are excited simultaneously and the impedance bandwidth is broadened to 140 MHz or more, which fully covers the entire worldwide ultra high frequency (UHF) band (860-960 MHz). The proposed antenna is printed on two FR4 substrates with a total volume of 56 mm×26 mm×3.2 mm. The measured read range was 4 m in a copper plate sized of 500 mm × 500 mm. Experimental studies demonstrate that the proposed antenna could work properly on general tagged objects.