Research On Beamforming And Channel Calibration Technology Of Broadband Passive Array Radar

Multichannel broadband passive array radar has the natural advantages of low detection cost,wide coverage at low altitude and free from the constraints of special frequency band.It has become an irreplaceable equipment system in modern military operations.Based on the " xxx equipment advance research project",this paper mainly carries out technical research on broadband passive array radar beamforming,broadband spatial spectrum estimation and broadband channel calibration,which provides a useful reference for broadband array channel signal processing and the promotion of a new generation of intelligent broadband radar system.The work and main innovations of this letter are as follows:1、Under the background of multiple interference source,the ADBF analysis is carried out for the passive radar uniform linear array.Based on the LCMV criterion,the conclusion that the adaptive algorithm has accurate main lobe guidance and obvious interference null is obtained;By changing the number of array elements,array element spacing,number of snapshots,signal-to-noise ratio and other parameters,the super-resolution estimation effect of MUSIC algorithm in passive array radar recovery of multi-target source is verified,and it is improved and extended combined with decoherence SSM and other algorithms.2、Aiming at the phenomenon of beam-squinting effect,the adaptive signal processing methods of full array and subarray of broadband passive radar are studied.Firstly,based on the principle of FIR transverse filter and ISM band division,a broadband beamformer is designed from two dimensions of time domain and frequency domain;Then,a uniform non overlapping dimension reduction subarray partition structure is proposed,which provides a strong technical support for improving the response efficiency of large-scale broadband passive array radar system;Finally,for the broadband target source whose incoming wave is LFM,under the condition of low signal-to-noise ratio,the "focus gain" RSS algorithm can accurately distinguish the azimuth of multiple coherent signals received by broadband passive array radar.3、In view of the difficulty of traditional narrow-band channel calibration methods to solve the channel inconsistency of broadband passive array radar,two classical channel imbalance models are analyzed,and the channel calibration model of broadband passive array radar is established.The convergence speed and equalization error of LMS and RLS adaptive filtering algorithms are compared and analyzed.An LMS active adaptive channel calibration method based on fir is proposed.The algorithm has simple form and small amount of calculation,It is easy to implement and can quickly and effectively calibrate the amplitude and phase parameter errors in the channel of broadband passive array radar.The research of this paper provides theoretical guidance and support for the engineering test and development of highly integrated broadband passive array radar.