ICAO Antenna for sidelobe suppression

The paper presents the Chu-Dunbar reflector antenna for primary surveillance radar 1.25-1.35 GHz and integrated monopulse system for secondary surveillance radar at frequency band 1.03 and 1.09 GHz. The main topic of this paper is the mechanical concept of a dipole antenna array that produces a monopulse antenna diagram at a horizontal (azimuthal) plane. The sidelobe suppression is cowered due to antenna array at the top of the reflector antenna.