Beam-Switching Antenna Using Reconfigurable Intelligent Frequency Selective Surfaces for Internet of Things Applications

Beam Steering antennas play an essential role in mobile applications, including Internet of Things (IoT) devices, due to their capability to control the beam direction, reduce the multipath problem, and enhance the spectrum efficiency. In IoT applications, a large number of devices are deployed over a wide area, and efficient wireless communication is critical to ensure reliable data transfer. The intelligent beam steering antenna technology can be used to dynamically control the radiation pattern of the antenna, providing improved signal quality and increased network capacity. This can result in reduced power consumption and increased battery life for IoT devices. This article presents a novel beam-switching antenna based on reconfigurable intelligent frequency selective surfaces (RI-FSSs) offering a wide steering angle. To cover the complete 360° range at 2.45 GHz, both mechanical and electrical switching are involved. Three frequency selective surface (FSS) panels based on periodic unit cells are arranged in such a way resembling a parabolic reflector. To achieve the required mechanical rotation angle, programmable step motors are installed. The switching between transmission and reflection is attained by varying the biasing of the PIN diodes through a programmable microcontroller. Both mechanical and electrical reconfigurability result in a beam-switching antenna system, having the capability to offer a continuous beam scanning range of 360° by using various combinations of FSS diode ON/OFF states, and the panels’ rotation angles. The proposed beam-switching antenna system is fabricated. The simulation and measurement results are in good agreement, which validates the operating principle of the proposed beam-switching antenna system. The FSS panels’ dimensions are
$0.13\lambda \,\times \, 0.1\lambda $
, where the overall size of the proposed antenna system is
$1.95\lambda \,\times \, 1.50\lambda $
. A beam scanning range of 360° with a gain of 10 ± 1 dB makes this a suitable candidate for IoT applications.