Research On The Broadband Wide-Angle Scanning Conformal Phased Array

Phased array radar is widely used in guidance, detection, identification, track and other fields, broadband phased array radar can achieve multi-target recognition and high-precision distance measurement, and has the advantages of low probability of interception, low accessibility, etc. Wide-angle scanning phased array radar can detect the target in the larger airspace so as to timely warn the fatal blow from certain blind area. Conformal technique is an effective mean to realize large angle scan for phased array radar. This thesis is going to research on the technology of broadband wide-angle scanning conformal phased array, the main contents are as follows:Firstly, designing a compact Vivaldi antenna with broadband and wide beam width according to the requirements of broadband and wide-angle scanning array to its element antenna. By the cut processing of antenna, the Vivaldi has a larger beam width. For Vivaldi antenna, three methods are proposed to effectively expand beam width in a wide frequency band, and the designed antennas are suitable for broadband and wide-angle scanning phased array.Secondly, focused on the phenomena of scan grating lobe and scan blindness in the scanning process for broadband wide-angle scanning plane phased arrays, triangular grid arrangement of array and two thin dielectric matching layers are respectively used to solve these problems. Designing a broadband wide-angle scanning planar phased array, which can realize the ±45 degree airspace scanning range in the wide frequency band 8~18GHz and 4dB gain loss scanning range is up to ±60 degree.Thirdly, for the design of broadband wide-angle scanning conformal array, the aperture projection method with amplitude and phase is given. Using generalized active vector pattern, the accuracy of conformal array synthesize is improved. And considering the shielding effect of conformal carrier, invalidation method for part element antennas is used to reduce the side-lobe in far field. Designing a broadband and wide-angle scanning cylinder conformal array in circumferential direction, which can achieve the ±75 degree scanning range in the frequency band 8-18 GHz.Finally, for the pattern synthesis of conformal array in the cylinder axis direction, an improved adaptive genetic algorithm is introduced. By introducing the concept of genetic diversity, the diversity of population in each generation is increasing, which can improve the prematurity in genetic algorithm. The conformal array in the cylinder axis direction can achieve broadband wide-angle scanning characteristics with the low side-lobe in far field.