2D Van Atta retrodirective array using dual polarized two-port square microstrip patches

A retrodirective array possesses the advantage that the reradiation field from all the elements has a coherent phase in the arrival direction of the incident wave. Such an array is thus useful in applications such as collision avoidance systems, toll management, freight management etc. Well-known retrodirective antennas are the corner reflector, which is a 3D structure and the Van Atta (1959) array. The Van Atta array is a planar structure comprising of antennas located and paired symmetrically in one dimension for 2D retrodirectivity, i.e. retrodirectivity in a single plane or in two dimensions for 3D retrodirectivity, i.e. retrodirectivity in three dimensions. In our application a Van Atta array for 3D retrodirectivity at 2 GHz was developed.