Wide-Angle Direction Finding with a Spatially Dispersive Reconfigurable Leaky-Wave Antenna

A novel radiation source reconstruction approach utilizing orthogonal interrogation modes is implemented to estimate the direction of arrival (DoA) of waves across a wide 1D field of view (FoV) using a single-port, spatially dispersive, reconfigurable leaky-wave antenna (LWA). Orthogonal interrogation modes are realized as fan-beam patterns with suppressed side lobes, steered at discrete angles within the range of −75° < θ < 75°. A model based on full-wave simulation of the LWA is employed to optimize the capacitance values of its tunable elements, thereby forming the orthogonal interrogation modes. A prototype LWA with 30 tunable elements is fabricated, and a data-analytic procedure is developed to refine the required voltage sets for these modes. Various scenarios, including single and multiple incident waves within a wide FoV, are evaluated through both simulation and measurement. The proposed implementation successfully estimates the DoA with an error of less than 2° within the FoV of −80° < θ < 80°. Consequently, the LWA can be integrated as a DoA estimation module at the edge of a standard reconfigurable intelligent surface, forming a self-aware wave re-direction device essential for enhancing indoor and outdoor communication performance.