Wideband Digital Array Radar Channel Correction Technology

Wideband digital array radar has many advantages compared with the traditional radar. However, the frequency characteristics of each channel is different because of the differences of LNA, Power Amplifier and other analog devices , that is Channel-mismatch, which seriously deteriorate the performance. of Digital Beamforming and Array Radar.First of all, several channel mismatch models are introduced, and the relationship between Channel-mismatch and performance deterioration is studied by simulation. Then, the characteristics and performance of the time domain algorithm and the frequency domain algorithm are analyzed, and their performances are compared by simulation. Besides, the relationships between parameters, such as the sample ratio, the taps, and performance of array radar are studied by another simulation, which provides a reference to the selection of parameters in projects.Unweighted least squares algorithm and direct inverse Fourier transform algorithm (DIFTA) are proved to be equivalent by anglicizing of their solution process, so they have exactly the same performance.An improved algorithm is proposed for the poor performance of the DIFTA. Firstly, analyzed the reasons of the poor performance using DIFTA, then, proposed to optimal design the idea frequency response function before Inverse Fourier transform. Finally, simulation show that the improved algorithm does improved the performance of array radar and no increment in Computational Complexity.FIR structure is difficult to obtain good performance in the channel correction, when a few peak appear in the channel mismatch that will lead to unit pulse response is a long sequence. To solve this problem, the Laguerre filter which includes some all-pass filter is introduced, and theory and simulation show that it has better performance.The efficient solution of Least Squares and FIR filter in engineering is described to meet the requirements of real-time. Finally, the method of optimizing program code is given by programming in ADSP-21161N EZ-KIT LITE, and the Channel-correction strategy with two ADSP chip is described.