DEVICE FOR BROADBAND RECEPTION BY AUTOTRANSPOSITION AND APPLICATION TO THE DETECTION AND CHARACTERIZATION OF RADIOELECTRIC EMISSIONS

摘要

The device according to the invention is based on the use of an antenna base formed of two antennas which pick up the emissions present and produce two radioelectric signals S1 and S2. These two signals are used to produce at least one intermediate frequency signal FI by demodulation of one of the two signals by the other (autotransposition). The demodulation is carried out by transposing firstly one of the signals, S1 for example, about a given frequency F1, the signal S2 being retained around its initial central frequency F0. Thus, regardless of the central frequency F0 of the emission picked up by the antennas, the demodulation produces a signal of central frequency F1, thereafter demodulated into a given intermediate frequency FI by means of a local oscillator of constant frequency F2=F1 +FI. The device according to the invention is applied to the production of a device for detecting emissions and for characterizing the emissions picked up.