Research On Channel Equalization And Beamforming Of Wideband LFM Phased Array Radar

Nowadays,both military and civil,the requirements for radar are getting higher and higher.Wide-band radar can improve the accuracy of distance measurement,so as to achieve high-resolution imaging of the target.Wide-band phased array radar has a great development prospect at present,attracting the attention of many radar researchers at home and abroad.An important problem of wideband phased array radar is its aperture transit time.When the aperture of the array increases and the scanning Angle increases,the performance of wideband phased array radar will be greatly affected.In this thesis,the broadband LFM signal is used,and a method of error correction,delay compensation and beamforming is discussed.This structure replaces the original analog delay line and places the deskew module in front of the digital sampling,which reduces the cost,sampling rate and the amount of subsequent calculation data of the radar system.The following work is carried out in this thesis :(1)firstly,the research background and significance of wideband phased array radar technology are described,and the development of wideband phased array radar at home and abroad as well as the research progress of wideband channel equalization at home and abroad are introduced.(2)the beamforming method of traditional phased array radar is introduced,including multi-beamforming method and zero-set suppression method for jamming signals,and the relevant simulation is carried out.(3)for LFM signals,a wideband digital beamforming method using analog de-skew is studied,the mathematical model of the wideband phased array radar is derived,and the simulation verification is given.(4)the influence of channel mismatched broadband digital beamforming performance is studied.This thesis introduces two commonly used mathematical models of mismatched channels,deduces the frequency response expression of mismatched channels,and deduces the mathematical model of the influence of amplitude-phase error on traditional beamforming.Finally,the corresponding simulation is given.(5)research on channel equalization correlation algorithm,introduce the wiener filter algorithm of time-domain channel equalization,the principle of adaptive time-domain equalization algorithm using least mean square error,and the principle of frequency-domain channel equalization algorithm using least square fitting,and carry out theoretical verification and performance analysis of the three algorithms mentioned above through simulation.