A Reconfigurable Antenna With Beam Steering and Beamwidth Variability for Wireless Communications

Abstract

A reconfigurable antenna (RA) capable of steering its beam into the hemisphere corresponding to $\theta \in $ {−40°, 0°, 40°}, $\phi \in $ {0°, 45°, 90°, −45°}, and of changing 3 dB beamwidth, where $\theta _{3\,\text {dB}} \in $ (40°, 100°), $\phi \in $ {45°, 90°, −45°} for broadside direction is presented. The RA operating in 5 GHz band consists of a driven patch antenna with a parasitic layer placed above it. The upper surface of the parasitic layer has two pixelated metallic strips, where each strip has four pixels. The pixels connected via p-i-n diode switches enable to change the current distribution on the antenna providing the desired modes of operation. A prototype RA was characterized indicating an average gain of 8 dB. Measured and simulated impedance and radiation patterns agreed well. The proposed RA offers an efficient solution by using less number of switches compared to other RAs. The system level simulations for a 5G orthogonal frequency division multiple access system show that the RA improves capacity/coverage tradeoff significantly, where the RA modes and users are jointly determined to create proper beamwidth and directivity at the access point antennas. For a hotspot scenario, the presented RA provided 29% coverage and 16% capacity gain concurrently.