System for the integration of I.F.F. sum and difference channels in a radar surveillance antenna

Claim 1

A system for the integration of I.F.F. sum and difference channels in a radar surveillance antenna including a horn type primary source and an offset type reflector illuminated by said primary source, said system comprising: two first radiating elements placed in said horn and forming an I.F.F. sum channel primary source; four second radiating elements placed two by two on either side of said horn and forming an I. F. F. difference channel primary source; first means to combine output signals of said first elements to form I. F. F. sum channel signals; and second means to combine output signals of said second elements to form I. F. F. difference channel signals, wherein said first and second radiating elements each comprise a first input/output terminal in vertical polarization and a second input/output terminal in horizontal polarization, said first means combine the output signals delivered by said first terminals in vertical polarization of said first radiating elements and said second means combine the output signals delivered by said first terminals in vertical polarization of said second radiating elements, and wherein said system further comprises: third means to combine the output signals delivered by said second input/output terminals in horizontal polarization of said second radiating elements and give a first neutralizing signal; a first phase shifter to phase-shift said first neutralizing signal by a first predetermined quantity; and a first coupler to mix the signal given by said first means and the phase-shifted signal given by said first phase shifter so as to deliver said I.F.F. sum channel signals.

Claim 2

A system for the integration of I.F.F. sum and difference channels in a radar surveillance antenna including a horn type primary source and an offset type reflector illuminated by said primary source, said system comprising: two first radiating elements placed in said horn and forming an I.F.F. sum channel primary source; four second radiating elements placed two by two on either side of said horn and forming an I. F. F. difference channel primary source; first means to combine output signals of said first elements to form I. F. F. sum channel signals; and second means to combine output signals of said second elements to form I. F. F. difference channel signals, wherein said first and second radiating elements each comprise a first input/output terminal in vertical polarization and a second input/output terminal in horizontal polarization, said first means combine the output signals delivered by said first terminals in vertical polarization of said first radiating elements and said second means combine the output signals delivered by said first terminals in vertical polarization of said second radiating elements, and wherein said system further comprises: third means to combine the output signals delivered by said second input/output terminals in horizontal polarization of said second radiating elements and give a first neutralizing signal; a first phase shifter to phase-shift said first neutralizing signal by a first predetermined quantity; and a first coupler to mix the signal given by said first means and the phase-shifted signal given by said first phase shifter so as to deliver said I.F.F. sum channel signals.