Research On Airborne Array Radar Adaptive Digital Beamforming System

Adaptive digital beamforming (ADBF) technique can greatly improve the capability of interference suppress. It's a key technique to improve target detective performance of modern radar. The application of ADBF is limited by the high cost of transmit/receive (T/R) modules. Over the recent years, the rapid progression in digital hardware and signal processing capabilities stimulates the development of phased array radar systems. The tendency is to move the digital interface toward the antenna, replacing, whenever possible, analog RF-hardware. Based on software codes, these digital systems are more flexible and easier to reconfigure than RF-hardware. Our research work comes from a project of airborne radar line array antenna's ADBF system.Firstly,this dissertation introduced the basic of linear array ADBF. And some mainly performance parameters when ADBF technology is applied in radar system are described. Two realizable ADBF algorithms, the sample matrix inversion (SMI) algorithm and DOA estimation algorithm based on MUSIC method, are presented. Simulations have been used to investigate their principle capabilities, limitations and performance parameters.This dissertation is focused on the application of ADBF. In order to control the sidelobe altitude of the adaptive pattern and to realize the ultra-low sidelobe performance of the array system, weighted steering vector and adaptive channel equalization technology are applied. Besides,some methods to resist the jamming are discussed.Finally, this dissertation introduced the parallel process system based on the most popular DSP ADSP-TS201 TigerSHARC. The flowchart of system design is given. And performance analysis and complexity are presented for this design. Assembly language programming and optimization are described in detail.