Angle of Arrival Antenna Array Design for BLE 5.1 Direction Finding

Indoor localization is the procedure of determining the precise position of an object or person within a confined space, such as building or room. Unlike outdoor global positioning systems (GPS) that rely on satellite signals, indoor localization faces extra challenges because of the absence of reliable GPS signals in indoor environments. Directional finding systems in Bluetooth Low Energy (BLE) frequently utilize antenna arrays based on the Angle of Arrival (AoA) method to determine the source of a BLE signal. This technology is widely utilized in situations like indoor positioning, asset tracking and location-based services. Thus, in this regard, 12patch antenna array is proposed in this paper for direction finding applications. A 12-patch antenna array is designed and fabricated using an FR4 substrate measuring 200 mm X 200 mm with 1.6 mm thickness. Additionally, simulation and design of the 12-patch AoA antenna array are conducted using Ansys Electronics Desktop 2021R1. The A3 patch antenna operates in 2.37-2.49 GHz frequency band with 2.40 GHz resonant frequency. Moreover, it has -20.30 dB return loss and 3.2 dBi gain. Also, the simulated results closely align with the measured findings.