Compact 2.45 GHz RFID Reader Antenna for IoT Networks

In this paper, a cross-dipole antenna functioning at a resonant frequency of 2.45 GHz is proposed for RFID reader used in IoT networks. The antenna design constitutes of printed dipole elements on the substrate's top and bottom surfaces. Each dipole element consists of a half- arrow shaped strip with a perpendicular stub. To achieve circular polarization, the design incorporates a delay line, which effectively connects the two perpendicular elements within each dipole pair. The antenna achieves an impedance bandwidth of 230MHz (2.37 GHz - 2.60 GHz) and an axial ratio bandwidth of 100MHz (2.37 GHz - 2.47 GHz). Notably, the antenna achieves a peak gain measuring 6.55 dB at 2.45 GHz, demonstrating its efficiency and exceptional performance for RFID readers.