A wideband beamforming antenna array for 802.11ac and 4.9 GHz in modern transportation market

In this work, a novel antenna structure has been proposed, which consists of multiple sub-array features i.e., a field selectable beam (90°, 180°, 270°, and 360°) and the choice of gain (11.16, 14.59 and 17.25 dBi) that can be easily adapted to cater for the dynamic scenarios in the transportation environment. The sub-arrays were designed using the microstrip patch antenna (MPA) concept with capacitive feed and dual substrate stacked up configuration for superior operating bandwidth covering the entire 802.11ac (5.17 to 5.85 GHz Industrial Scientific and Medical (ISM) band), in addition to the extended coverage for 4.92 to 4.98 GHz licensed band with narrow azimuth beamwidth of 24°. The sub-array was designed, simulated and experimentally evaluated and the beamforming results revealed that the antenna structure can be integrated with beamforming concepts to provide an enhanced wireless link between the ground base station and the mobile terminals that allows beam steering to focus on the targeted direction and null the interference directions with small beam width. It is expected that the proposed configurable gain/beam beamforming antenna array will further reduce the deployment cost and enhance the anti-interference performance by two-fold, and shall bring the user experience in the transportation market to the next level.