Study On Algorithm Of Angle Measurement In Planar Array Antenna Phased Array Radar

With the invention of high-speed aircraft and the antenna inertia reasons,traditional mechanical scanning radars have more and more difficult to detect the high-speed aircraft. With the huge advantage of beam switching speed and flexible beam forming, phased array radar has been widespread concerned in countries, and it is also a radar system that we focus on in this paper. For large planar array antenna phased array radar, its antenna number may be up to several thousands, which leads to the target angle measurement computation great, and hence the real-time implementation are difficult to realize. So, how to reduce the amount of computation of angel estimation under planar array radar is an important research direction. This thesis studies the problem of how to reduce the great amount of computation under the planar array radar.First, signal model of linear and planar array and beamforming technology is introduced. Then, several conventional angle estimation methods are presented, including conventional beam scanning method and Capon minimum variance method. Finally, the maximum likelihood method is introduced, and its relationship with the beam scanning method is analyzed. The maximum likelihood method involves multidimensional optimization, as well as Capon minimum variance method involves matrix inversion, so they have a high computation complexity in practice and is hard to realization for practical engineering application. In the case of linear array, traditional beam scanning principle has the advantages of simple principle relatively small computation and good performance. Therefore, beam scanning angle estimation method algorithm has great advantages in the computation. However the traditional method requires simultaneous beam scanning in elevation and azimuth dimension for planar array antenna, so that the amount of computation will increase sharply. To solve this problem, this thesis presents an improved two-dimensional beam scanning method which considering the couple of elevation and azimuth caused by the incline of planar array antenna and using the priori information of beam pointing.The improved two-dimensional beam scanning method can reduce the computation complexity of the two-dimensional beam scanning method drastically by converting the two-dimensional beam scanning into two one-dimensional beam scanning and has an approximate angle measuring performance. At last, by the research of the single pulse angle measurement methods, a single pulse angle measurement method for planar array antenna is proposed.This method can further reduce the computation of angle measurement for planar array and has a comparable performance.