Accurate limited angle traking with a phase array antenna using zero-knowledge beamforming

As the accuracy of the position sensors such as gyroscope improves their price increases significantly. Low cost gyros have difficulty in measuring the small angular displacements, e.g. |deltathetas| < 1deg. We introduce a new method to sense the direction of the target´s motion for small angular displacements, using the beamforming information of a phased array antenna. In this method we use 2-sided gradient approximation combined with the least mean square (LMS) adaptive filter, henceforth called zero-knowledge beamforming, to update the input voltages of the phase shifters. When the beamforming process converged and the final values of the voltages were obtained, we compare these voltages with a database to extract the target location information. This database was provided with exhaustive field tests and measurements.