Orthogonal nulling of multiple jammers with monopulse preserving

Advanced monopulse processing techniques such as mainlobe cancellation, 2-target monopulse and an enhanced angle-estimation technique based on 2 sets of monopulse ratios make use of an additional delta-delta beam compared with the conventional monopulse system. The salient feature of the mainlobe cancellation technique is the maintenance of monopulse angle estimation accuracy while canceling a jammer within the main-beam. The technique is based on an orthogonal nulling concept where jamming is canceled in one angular domain and monopulse processing is carried out in another angular domain. This feature can also be described in terms of antenna product beam patterns where the common adapted beam patterns are canceled out leaving the monopulse ratios un-distorted. In this paper, we present some extensions of this technique for coping with multiple mainlobe and/or sidelobe jamming using the digital beamforming capability.