1 / 2017-04-18 16:20:52

An Overview of Mainlobe Cancellation with Some Extensions

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Mainlobe cancellation makes 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. The technique corresponds to partial adaptivity where degrees-of-freedom are exploited for both jamming cancellation and monopulse angle estimation. The paper also includes an extension of mainlobe cancellation to non-rectangular aperture.