Two-State Feedback Loop Adaptive Arrays for Pulsed Interference Signals

A two-state feedback loop is presented which increases the effectiveness of an adaptive array in the presence of pulsed interference signals. In the case of the two-state feedback loop, one state permits the maximum adpative response, consistent with the loop stability, and is activated in the presence of an interfering pulse. During the other state, which is activated when the interfering pulse is off, the weights are frozen at the values reached at the end of the last interfering pulse and are maintained until the next disturbance occurs. It is shown that an adaptive array with the proposed two-state loops steers permanent minima in the direction of the interfering signals, irrespective of their duty cycle. The performance of a communication system protected by such an adaptive array improves significantly over one protected by a conventional adaptive array.