Research On Multichannel Strong Electromagnetic Pulse Signal Processing

In this paper,based on the requirements of the project of Guizhou Aerospace Metering and Testing Technology Institute "Research on High-power Microwave Strong Electromagnetic Pulse Testing Technology",the multi-channel strong electromagnetic pulse signal acquisition system is studied.Firstly,the related technology of high power microwave signal is studied,including the basic principle of polarized antenna,geophone structure,sampling theorem and electromagnetic protection,etc.Then,according to the task requirements of the project,the hardware circuit and software part of the pulse signal acquisition card were designed,including structure block diagram planning,circuit diagram design,FPGA control program design,PCB layout drawing and IP core call,function simulation,upper computer program writing,etc.The main control unit of the acquisition card in this design is a digital-to-analog conversion unit composed of ADC chip and FPGA controller.The AD9643 dualchannel 14-bit ADC is used to receive the horizontal component and vertical component of the pulse signal.EP4CGX150 is selected as FPGA chip,in addition,communication unit,temperature control unit,FPGA configuration unit,analog signal processing unit and other peripheral units constitute a complete pulse signal acquisition card.Acquisition card has the following characteristics: in order to improve the accuracy of signal acquisition using amplifier to adjust the gain of analog signal;Using RS485 serial port and optical fiber module two ways to communicate with the host computer and other equipment;The temperature state information of the nodes of the controller is collected in real time and the working state of the acquisition card is controlled according to the temperature information.Two-clock FIFO IP is used to check a large number of collected data for buffering and data transmission across clock domains.FPGA has rich expansion pins.With the cooperation of external resources,the function of the acquisition card can be upgraded according to different scenes or requirements.To sum up,the acquisition card has many advantages such as flexible configuration,low power consumption,small size and so on.Finally,through testing and verifying the function of each module and the function of the whole system,the functions of each unit of the acquisition card are effectively realized,and the waveforms of multi-channel signals can be displayed normally on the upper computer interface of Lab VIEW.It can be seen that the design basically meets the requirements.