A focused beam forming algorithm with null constrained weight

A null weight constrained by zero and first derivative based on focused beam forming is proposed in this paper. The weight can put null on the given positions which are only decided by the interference´s positions. The weight also has advantages in high robustness and low computation account which doesn´t have to be calculated on real time. Simulations about single and multiple interferences on the condition of different SIR are proposed in the paper. And the results show that the new weight proposed in this paper can get target´s image while putting nulls on the coherent interference´s position.