Bandwidth-Enhanced Compact Beamsteering Antenna for IoT Platforms

A technique to enhance the bandwidth characteristics of spherical modes-based beamsteering antennas is investigated in this work. The solution comprises a top-loaded monopole, a shorted ring antenna, and a metasurface layer used for bandwidth enhancement. It is demonstrated that the proposed antenna can scan continuously across the entire azimuthal plane. The antenna operates at the center frequency of 4.42 GHz where the size with respect to wavelength is 0.73λ × 0.73λ × 0.18λ. The overlapping -10 dB impedance bandwidth covers 265 MHz, where the total efficiency stays above 77%. Owing to its compact size and enhanced bandwidth performance, the design is proposed as a good candidate to enable advanced modern wireless applications in small-scale Internet of Things (IoT) platforms.