Pattern Null Steering Using the Cross Entropy Method by Controlling Only the Current Phases

To eliminate interference from certain direction, antenna array null steering become an important technology. In this paper, A CrossEntropy method based on Importance Sampling strategies is applied to null steering by controlling only the current phases. In this method, the population samples are sampled from a parameterized probability distribution during the optimization procedure, so the diversity of the samples can be kept, and the samples set is close to best optimization result. This method not only effectively overcomes the premature phenomenon but also accelerates calculation speed. Simulation results indicate that nulls can impose at three locations: in the neighborhood of the main beam and sidelobe, and at symmetric places with respect to the main beam. In addition, the region of null steering by using the method is larger than that of other methods. When zero power width of mainlobe is 12⁰ and the maximal side lobe is -12dB, average null steering level is -192.12dB which is three times more than immune algorithm’s level.