An improved two-stage processing approach of adaptive monopulse at subarray level

The adaptive monopulse at subarray level is required for applying monopulse technique in multi-function phased array radar. The two-stage processing approach is studied, which is for adaptive monopulse at subarray level in planar phased array. The four-channel monopulse system is adopted, in which the delta-delta channel is used as an auxiliary channel. The signal model of adaptive monopulse at subarray level is presented. An improved two-stage adaptive jamming suppression approach at subarray level is proposed. The first stage of adaptive processing is used to suppress the sidelobe jamming, while maintaining the mainlobe shape at the same time. Besides, we modify conventional approach which combines ADBF at subarray level with mainlobe maintenance technique, so that it suppresses sidelobe of adaptive patterns effectively and improves mainlobe maintenance effect remarkably. The second stage of adaptive processing is used to suppress mainlobe jamming, while preserving an undistorted monopulse ratio. Simulation results demonstrate that the presented approach can suppress jamming effectively, while preserving good monopulse performance and approximating the adaptive monopulse ratio to the quiescent one at the same time.