Angle-of-Arrival Detection Using Photonic Integrated Circuit and Array-Beam Space Mapping

In this work, angle-of-arrival (AoA) detection using a two-dimensional (2D) antenna array coupled to a planar photonic integrated circuit (PIC) is demonstrated. To detect AoA in azimuth and elevation (az-el) the received signal from each antenna element, in a 2D array, is up converted to the optical domain using an electro-optic modulator and transmitted to a PIC via optical fiber. To preserve the two-dimensional phase information captured by the array, a special array-beam space (AB) mapping is used to route the fibers to a linear array of input waveguides on the PIC. This paper presents the steps to generate such a mapping for the antenna elements, as well as an equivalent mapping for the array's beam space. We also present experimental results for beam detection using a 30-element hexagonally spaced array. The PIC-based approach promises to reduce system size and reduce latency for AoA detection.