Investigation of Direction of Arrival Estimation Using Characteristic Modes

A method is proposed to estimate the direction of arrival (DoA) of a traveling wave from characteristic mode weighting coefficients. These are obtained from the currents through the ports positioned on an antenna structure. The additional insight into the behavior of the antenna structure gained by the modal analysis is utilized to create a set of ports that allows to use a single conducting structure for the direction finding. It is shown that the proposed method works for a cubic antenna structure with 20 uncorrelated ports with good accuracy for any DoA.