A Dual Band Circularly Polarized RFID Reader Antenna for Internet of Things Application

This article proposes a unique approach to design RFID Reader antenna for Internet of things applications. Here a circular patch with two orthogonal slots etched on the patch is used to acquire UHF RFID band at 915 MHz and WLAN band at 2.45 GHz. Four slits on the ground plane are etched to improve the axial ratio. To minimize the back lobe and enhance the gain at both bands, we have employed a dual-band AMC reflector. Our results show the simulated 3dB axial ratio bandwidths of 4.2% and 2.1% at UHF and WLAN bands respectively with gains of 4.5dBi and 7.2dBi. This antenna system is ideal for IoT applications.