A 2.4 GHz 3D Quasi-Isotropic Electrically Small Antenna with Magnetic Dipole Characteristics for RFID Applications

Seeing the recent rise in applications of RFID tags in industrial internet of things (IIoT), it become very evident to design an efficient and compact antenna which is able to satisfy the uprising IoT demands. This work presents a new 3D quasi-isotropic electrically small antenna (ESA) for RFID applications in the 2.4 GHz band. The proposed antenna is designed on a single perfect electric conductor (PEC) sheet by loading an inverted L-shaped slot. An opened aperture is excited to realize magnetic dipole characteristics to achieve a quasi-isotropic radiation pattern in 3D spatial coverage. The overall volume of the prototype is O.18Ax0.07Ax0.0096A nm³; here, λ is the free space wavelength that corresponds to operating frequencies. The proposed antenna offers a 30MHz (2.42-2.45 GHz) impedance bandwidth centered at 2.43 GHz. The antenna exhibits a quasi-isotropic radiation pattern with a maximum efficiency of 85%, which makes it suitable for RFID applications.