A Novel Microstrip Array Antenna with Coplanar Parasitic Elements for UHF RFID Reader

A novel RFID reader antenna for 910–915 MHz is proposed. The antenna is microstrip array configuration, which mainly consists of three elements rectangular radiation patches and several coplanar parasitic elements. The parasitic elements could broaden impedance bandwidth in the limited substrate thickness and rectify the resonant frequency well. In the paper, the antenna configuration, design methodology, simulated and measured results are carefully discussed. The experimental results indicate, in the operating band, that VSWR is less than 1.25. And because of arranging array, the antenna radiation pattern has a good coverage in H-plane. It makes the tag be identified in large range and high speed. The antenna is well suitable for the application in railway RFID circumstance.