A Millimeter-Wave Shared-Volume Dual-Aperture Antenna Array With Enhanced Spatial Coverage Efficiency for IoT Devices

This paper presents a millimeter-wave shared-volume dual-aperture antenna array with enhanced spatial coverage efficiency for IoT devices. The antenna unit is implemented with two substrate integrated step horns sharing the volume of a cube. The radiation apertures of the two step horns are perpendicular to each other, namely the horizontal aperture and the vertical aperture, enabling a large spatial coverage with a small size. The working bandwidth of the horizontal aperture is from 22 GHz to 37 GHz, and the working bandwidth of the vertical aperture is from 19 GHz to 30 GHz. A 4-element linear array is proposed using the antenna unit. The horizontal and vertical subarrays obtain an average 11.5 dBi and 10.5 dBi realized gain respectively, with –3 dB scanning angle being up to ±35∘ at 27 GHz. A simulation is conducted by deploying the designed array in a smartphone to demonstrate its performance in practical applications. The spatial coverage efficiency of the proposed antenna array is calculated to quantify its spatial coverage capability. A prototype of the 4-element array is fabricated and a good agreement is achieved between the measurement and the simulation.