An Analog Open-Loop Adaptive-Array Antenna System

A new open-loop adaptive-array system with excellent transient behavior is presented. The system is constructed of analog circuits and determines complex weights without using the feedback of the array output. The performance attainable with the system is described in detail. It is shown that the convergence rate of the system does not depend on a noise environment but is determined by the time constant of the low-pass filters included. Moreover, it is shown that although the steady-state performance is quite good when the interference sources differ widely in signal strength, the steady-state performance can be far below optimum when two or more interference sources are present at roughly equal power levels.