Design And Implementation Of Multi-channel Data Acquisition Unit Based On FPGA

In the field of radar detection and electronic countermeasures,with the improvement of carrier frequency and signal bandwidth,the requirements for transmission rate and data processing capacity are becoming higher and higher.Due to the difficulty of synchronous acquisition of high-speed signals,poor phase consistency between channels and data alignment,multi-channel data acquisition technology is particularly important.Field Programmable Gate Array(FPGA)can realize multi-channel data parallel processing in parallel computing mode,and has the characteristics of rich logic resources and complete level interfaces.Based on the advantages of FPGA,a high-performance multi-channel high-speed data synchronization acquisition device with FPGA as the core is designed.Main work contents include:Firstly,three typical data acquisition architectures are analyzed,and then the high-speed interface and data synchronization technology are emphatically analyzed.Through application scenario and requirement analysis,it is decided to use zero if architecture and JESD204 B high-speed interface.Finally,in order to optimize the analog performance and maximize the digital function,the digital-analog separation method is adopted to analyze the function and performance from two aspects: analog signal acquisition and digital signal processing.Secondly,completed the hardware circuit budget and specific circuit design,mainly for analog signal acquisition circuit,digital signal processing circuit and external communication interface design.The Analog signal acquisition circuit mainly receives four 700MHz?1600MHz frequency band signals,which are sent To Analog To Digital Converter(ADC)after amplification and filtering.The digital signal processing circuit takes FPGA and ADC as the framework,integrates various communication interfaces,such as RS422 and network port,and realizes digital signal processing and data uploading communication functions.Finally,the layout of external communication interfaces is completed,including four analog signal receiving ports,two gigabit network ports,one optical port,and two groups of BEidou GPS antenna interfaces.Thirdly,the analog signal acquisition circuit,digital signal processing circuit and the performance test of the whole equipment in the multi-channel data synchronization acquisition equipment are completed.The test results show that the equipment can achieve multi-channel phase consistency less than 1.8° under the condition of 200 MHz bandwidth,and all other indicators meet the design requirements.The paper designs and implements the hardware circuit design of 4-channel analog signal acquisition and processing.The channel isolation degree is more than 65 d B,the receiver sensitivity is better than-91.5d Bm,and the multi-channel phase consistency is less than 1.8°.It provides a certain reference for multi-channel data acquisition scheme design and engineering implementation.