A broadband beam former with pole-zero unconstrained jammer rejection in linear arrays

A new architecture is presented for broadband cancellation of jammer signals in a linear equally spaced array of sensors, where the jammers can be coherent or noncoherent with the target signal. Unique features lie in the ability of the preprocessor to cancel all poles in the ideal filters and simplify the remaining zeros. As a result, the adaptive process for jammer cancellation need only estimate these zeros with short-length digital filters and any generally available adaptive algorithm. The adaptive process is unconstrained and can use any least squares method including those with a lattice structure. The number of filters is equal to the maximum number of jammers and their length is unaffected by the number of array elements. The required lengths of the adapted filters are functions only of the jammer directions. The target signal may be weak or strong in comparison to the jammers, and there are no known deficiencies such as signal cancellation or look-direction bias.