METHOD OF SUPPRESSING INTERROGATOR SIDE LOBES AND RECEIVER FOR REALISING SAID METHOD Russian patent published in 2011 - IPC H04B15/00 

FIELD: physics.

SUBSTANCE: signals received from main and compensating antennae at different intermediate frequencies undergo conversion in receiver mixers, and the frequency of the received frequency-time coded radio pulse signals is then converted in a limiter for suppressing the weak signal with one frequency of a strong signal with another frequency using heterodynes, where the frequency of one heterodyne is set lower than the least code frequency of the signal by the intermediate frequency value. The frequency of the other heterodyne is set higher than the greatest code frequency of the signal by a value equal to the intermediate frequency, and after frequency division the video signal which corresponds to one frequency-time coding frequency is delayed by a time equal to the code interval (tk) and in a coincidence circuit the delayed and the non-delayed video signal, which corresponds to another frequency-time coding, is checked for coincidence in time. If the signal from the main antenna is greater than the signal from the compensating antenna, a video signal appears at the output of the coincidence circuit, otherwise the video signal does not appear at the output of the coincidence circuit. The receiver which realises the said method has on the input a main and a compensating antenna connected in series to filters, mixers and intermediate frequency amplifiers and frequency dividers. Heterodynes are connected to the mixers. The frequency of one of the heterodynes is given less than the least code frequency of the signal by the intermediate frequency value, while the other is greater than the greatest code frequency of the signal by the same intermediate frequency value. The first output of the frequency divider is connected to series-connected delay line (1) and a coincidence circuit, whose second input is connected to the output of the delay line (2), which is connected to the output of the frequency divider. The output of the coincidence circuit is the output of the receiver.

EFFECT: suppressing interrogator side lobe signals using a receiver of frequency-time coded radio pulse signals, with processing of signals from the main and compensating channels in one intermediate frequency amplifier and without expanding the transmission band for auxiliary signals.

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