Abstract: Disclosed is a method and a device for the on-line testing of an antenna formed by a plurality of radiating sources. In an application for example to a secondary radar antenna, it is proposed to memorize the patterns (.SIGMA., .DELTA. and .OMEGA.) of the antenna when all the radiating sources work properly and, when each of the source is malfunctioning in turn, to meaasure the radiation patterns of the antenna during its operation in IFF mode and then to compute the coefficients of correlation of these patterns with all the corresponding memorized radiation patterns. The value of the coefficients obtained enables the precise determining and localizing of the malfunction. It is furthermore proposed to use a ground beacon responding to all the interrogations on several antenna rotations.

Abstract: A device for delaying an electric signal comprising means for acquiring the signal, sampling it at a frequency f.sub.e and delivering it in parallel in the form of binary words of M bits, at a frequency f.sub.m such that f.sub.m =(f.sub.e /M); means for storing said binary words for a given period of time and operating at the frequency f.sub.m and means for restoring at frequency f.sub.e the signal from the binary words.