Research On Generalized Digital Beam Forming Of Array Antenna

Thanks to the vigorous development of today's digital technology,digital beamforming technology is widely used in fields such as phased array radar and communication engineering.This technology is based on the theory of phased array antenna beam forming,and uses digital signal processing to replace the phase shifter in the original array radar to control the scanning characteristics of the antenna.Compared with traditional beamforming,digital beamforming technology allows the signal to get the maximum output in a specific direction,while reducing the use of a large number of phase shifters and amplifiers in array radars,which simplifies the radar structure and reduces costs and losses.Based on the principle of digital beamforming,this paper proposes the concept of generalized digital beamforming while studying the application of digital beamforming technology in traditional millimeter wave radar.The concept of generalized DBF is to control the on and off of the antenna unit by digital technology to achieve the beamforming of the reflective array antenna.The essence of both is to achieve beamforming by digitally compensating the phase difference between the antenna array units.In the research of traditional millimeter-wave radar digital beamforming,this article samples the IF reflection echoes of FMCW radar from a specific distance and six different angles,and performs digital beamforming and radar distance detection on the sampled data in MATLAB.After that,write Verilog code and verify it with Modelsim.Finally,the feasibility of the algorithm was verified by comparing the software and hardware simulation results.In the research of generalized digital beamforming,this paper is based on the study of the principle of metasurface reflection array antennas.First,the software simulation of metasurface reflection array beamforming is performed.After that,the hardware was selected according to the actual indicators,and a digital coding control board with an FPGA development board was designed and processed,and the Verilog was written to control the on and off of the PIN diode on the 12 × 12 reflective array antenna unit.Finally,the reflection beam can be adjusted.In terms of coding design,this paper has designed four static coding and two dynamic scanning coding.On the PC side,through serial port debugging,the codes in different states can be sent to the FPGA,and then the high and low levels corresponding to the codes are sent by the FPGA to different PIN diode,so that the reflection array beam can be adjusted in real time.This has also been successfully implemented in board experiments.