Research On Beam Forming And Sidelobe Suppression Of Phased Array Radar

Phased Array Radar refers to changing the direction of the radar scan by changing the synthesis way of the beam emitted from the array antenna, including active electronically scanned array radar or passive electronically scanned array radar. This design is different from the mechanical scanning radar array, which can reduce or totally avoid using motor-driven mechanical radar array to achieve the purpose of covering a large detection range. Nowdays, the way of electronical scanning includes changing the frequency or changing the phase, both of which can realize beam scanning by redirecting of synthesized beam.Under the context that Phased Array Radar has been applied widely, in this thesis, the array beamforming, the array sidelobe interference suppression and other aspects are studied and simulated based on the Phased Array Radar antenna technologies. The main contents are as follows:(1)In this paper, based on the general working principle of Phased Array Radar array antennas, the signal forms, transported and received by radar system, are derived, and the signal modles that needed in simulation are obtained finally.(2)For analyzing Phased Array Radar beamforming deeply, taking airborne Phased Array Radar as an example, the conformal array antenna beamforming is studied. At the same time, the influence of beam forming, made by array elements errors caused by the flexible deformation of the wing, is analyzed. Kalman filter algorithm is used to track and predict the array deformation curves, and then the prediction results are used to compensate the antenna error.(3)Based on the principle of the sidelobe blanking anti-jamming technology, the performance of its system is analyzed and studied by deriving probability formula and MATLAB simulation. According to the blanking effects of the coherent repeater interference, the advantages and disadvantages of SLB anti-jamming technology are summarized. On the basis of this, several improved multi-threshold sidelobe blanking systems are introduced briefly.(4)The basic principle of the sidelobe cancelling anti-jamming technique and the parameters of system performance measurement are studied. The popular cancelling algorithms are also introduced and simulated. Combined with the typical method of phased array radar signal processing, an anti-interference model is established and simulated, which provids a reliable theoretical basis for the practical engineering using SLB/SLC technologies.