Slot-array antenna for UHF RFID shelf applications

This article presents a linearly polarized slot-array antenna that consists of a slot series-fed by a microstrip line for radio frequency identification (RFID) shelf applications in the ultra-high frequency band in which the end of the microstrip line is shorted to the ground plane by a via-hole. The radiating element is a U-shaped slot etched in the ground plane on one side of a substrate and the microstrip line for feeding is etched on the other. The designed 6 × 3 array antenna has the near-field distribution of electric field intensity from 0.5 to 3.36 V/m for RFID shelf applications. The fractional bandwidth for a reflection coefficient of less than −10 dB is approximately 5.5% at 920 MHz, ranging from 892 to 943 MHz. The antenna installed in the RFID shelf stably reads pharmaceutical products with various package options on the shelf. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1511–1515, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27653