Abstract
This paper aims to enhance the gain of a microstrip patch antenna for ultra-high frequency (UHF) radio frequency identification (RFID) reader. The paper proposes a new antenna design that consists of a perfectconductor rectangular patch with a quasi H-shaped slot using a flame retardant substrate and an aluminum ground plane. In order to improve the gain while keeping a modest antenna size, an empirical parametric study is performed using the CST Studio Suite software. As a result, an enhanced slotted antenna design is obtained with a total size of 136 x 124 x 3 mm(3) and a gain of 5.24 dBi at 922-MHz frequency. Such a gain magnitude is shown to be significantly higher than those obtained by analogous single patch antennas.