Multi-channel Receiving Circuit And Signal Preprocessing Logic Design Of High Frequency Multi-Beam Sonar

Multi-beam sonar is an important tool for ocean exploration and development.This paper comes from the development of a high-frequency multi-beam sonar prototype,which is responsible for the design and implementation of multi-channel receiving circuit and FPGA logic of signal preprocessing.Firstly,this paper briefly expounds the research background and significance of multibeam sonar,and generally introduces its history and working principle at home and abroad.Secondly,the overall scheme of the multi-channel receiving and acquisition circuit is designed.According to the technical index parameters,the preamplifier circuit,the controllable gain amplifier circuit,the band-pass filter circuit,the amplitude and phase adjustment circuit,the A / D acquisition circuit and the gain control circuit in the multi-channel receiving and acquisition circuit are designed.The overall layout of the receiving circuit is determined,and three 36 channel receiving PCB boards are drawn.Then,the band-pass sampling,orthogonal transformation,down-sampling and multiphase filtering algorithms are introduced,and the signal preprocessing scheme is designed.The implementation logic of band-pass sampling,orthogonal transformation and multiphase extraction filter is written based on FPGA.The processing effect of the algorithm is compared and the logic timing simulation is carried out.Finally,the multi-channel receiving circuit is debugged and tested,and the system function is verified by pool test and Qiandao Lake test.