Design Of Multi-channel High Speed And High Precision Acquisition Unit Based On PXIe

Due to the rapid development of modern electronic technology,which accelerates the complexity of the electromagnetic environment in space,real-time test analysis of complex electromagnetic interference signals is essential.Broadband high-speed acquisition system is the core part of the time domain electromagnetic interference receiver,its sampling rate and acquisition accuracy index determine the ability of the magnetic interference receiver to capture electromagnetic interference signals with transient broadband large dynamic range characteristics,and in order to achieve real-time analysis of the collected data,it is necessary to meet the high-speed high throughput data fast and stable transmission.The PXIe based high speed and high precision data acquisition unit can meet the requirements for efficient capture and real-time analysis of complex signals,and has the flexibility and scalability of modular instrumentation,which is of profound research significance.The high-speed,high-precision data acquisition unit based on PXIe in this thesis is derived from a national major instrumentation project.It adopts a two-slot standard 3U board structure,and effectively separates and designs the analog signal conditioning part and the digital signal processing part to realize the reception,acquisition and processing of broadband signals.This dissertation examines the following components,including:1.The overall design of the acquisition module is introduced,including the conditioning,acquisition and processing of analog signals,and the stable and low latency transmission of data through a high-speed serial bus,and the design of the entire dual-slot 3U board structure is proposed.2.By analyzing the metrics of the analog channel,the specific circuit-level implementation analysis of the vertical amplitude conditioning part of the analog channel and the trigger signal generation part was completed.In the analog channel section,a specific analysis and implementation of various amplitude regulation functions such as fixed attenuation,fixed gain and variable gain included in the input power division module and post-stage amplitude regulation are introduced.3.The design of high speed and high resolution signal acquisition and processing module is investigated,the selection of key devices and the specific design and analysis of hardware circuitry are completed through index analysis,and various FPGA-based digital signal processing implementations including digital filters are introduced.4.Based on the theoretical analysis and simulation,the significance of the acquisition architecture in improving the dynamic range and signal-to-noise ratio parameters of the system is demonstrated,and the analysis and implementation of the acquisition architecture in this module is completed based on the simulation results.Through the research and design of the above,the PXIe based acquisition unit design with 300 MHz real-time signal bandwidth,1GSPS sampling rate and 14 bit sampling accuracy was completed,which can realize the capture and identification of-77dBm~13dBm total 90 dB signal dynamic range.