Software defined digital beam forming processor

In this paper, we propose a software defined reconfigurable digital beam forming (DBF) system. The system produces 43-degrees beam-width with 22.7 dB main-to-side-lobe ratio (MSLR) and steer the beam with beam pointing accuracy of ±2 degrees with just 4 element antenna array. The proposed system is realized on the latest field programmable gate arrays (FPGA) and digital signal processor (DSP). One of the two FPGAs performs data acquisition and down sampling while the other FPGA performs beamforming and sidelobe cancellation. The Texas Instruments (TI) DSP is used for online FPGA parameters configuration. Special purpose software is developed for online configuration and to display processing results. The system operates with 4-channels input IF signals taken from off the shelf radar simulator. To achieve the desired (MSLR), Dolph-Chebyshev's window is used to manipulate the signal after phase adjustment. After performing the side-lobe cancellation and beamforming by FPGA, the output is sent to computer via Compact Peripheral Computer Interconnect (CPCI) where the direction of arrival (DOA) of target and beam pattern is displayed.