The Far-Field Threshold Evaluation of the Frequency Diversity Arrays

In this paper, a problem of the evaluation of the far-field (Fraunhofer) zone (FZ) threshold of the frequency diversity arrays (FDA) for multipurpose using is presented. It is shown, that because of space-time dependency of the array field, such parameters of partial signals as a relative bandwidth, a spectrum overlap factor and an amplitude distribution should be taken into account for FZ threshold evaluation. Criteria for FZ threshold based on the relative errors of the evaluation of the time-dependent directivity factor is proposed. As an example of the linear equidistant FDA, estimates of the FZ threshold by proposed criteria are obtained. The results can be useful to the design of processing algorithms of cognitive control for FDA radars, as well as in experimental and simulation studies.