Statistical Description of Nonlinear Signal Processing in Array Antenna Systems

A statistical analysis is made of a superlimited phased array when a sinusoid and Gaussian noise are independently introduced into the element-channel antenna elements. A mathematical expression is derived for the probability-density function of the beam-channel envelope in tenns of element-channel signal-to-noise power ratio and angular position of target from main beam. This density function is used to study the envelope detection capabilities of a superlimited phased-array system. A comparison study of the detection capabilities of the superlimited phased array and a linear system points out the "sidelobe suppression effect" and the "noise quieting effect" exhibited by the nonlinear system. Experimental results obtained with a 60-element array antenna system with noninear signal processing are reported and compared with theory.