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

This article 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 to 37 GHz, and the working bandwidth of the vertical aperture is from 19 to 30 GHz. A 4-element linear array is proposed using the antenna unit. The horizontal and vertical subarrays obtain an average 11.5 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.