A real-time/low-cost DOA estimation system based on Rotman lens array antenna

This work proposes a real-time and low cost direction-of-arrival (DOA) estimation measure. The system is based on a Rotman lens to simultaneously detect signals from a broad angular sector. Lens beam ports are connected to low cost power detectors. Received power levels are then fetched by a multi-channel data acquisition card to form a reception signal vector. The vector is then normalized and compared with the reception pattern data base formed from the antenna's measured patterns acquired in an anechoic chamber. By comparing the measured pattern with ideal patterns of various incident angles, error vectors can be formed as an indicator of likely DOA. This concept is realized with a real time system. Field test results demonstrate the feasibility of the proposed DOA estimation approach.