摘要 |
An antenna system comprising two similar antennas with a monopulse feed system is scanned while transmitting in-phase radio waves from the two antennas. Reflected radio waves are received by the two antennas and fed to a hybrid circuit which in turn produces a sum signal SIGMA and a difference signal INCREMENT . After detection is performed by a detector, a signal processing unit performs double differential processing on the sum signal SIGMA and the differential signal INCREMENT . In this processing step, the sum signal is output only if the double differential coefficient of said sum signal is equal to or less than a predefined positive real number value and if the double differential coefficient of said difference signal is equal to or greater than a predefined negative real number value, and a zero signal is output in any other cases. Thus, the beam width of an antenna pattern is compressed without missing a necessary output signal.
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