DOA Estimation by Polynomial Rooting for Electronically-Scanned CRLH Leaky-Wave Antennas

Direction finding by means of leaky-wave antennas is considered, and a computationally-efficient subspace algorithm is obtained thanks to the algebraic structure of the data outputted by a two-port electronically-scanned composite right/left handed leaky-wave antenna. Identifiability conditions are expressed, in terms of the number of cells and the number of beams, in relation with the number of illuminating sources. We develop Fast (as opposed to search-based) MUSIC algorithms to estimate angles of arrival, including when the leakage factor is unknown. Simulation tests are conducted that show the ability of the algorithm to handle the uncertainty about the leakage factor and/or the number of sources.