A broadband transient electromagnetic pulse signal acquisition device

Abstract

The invention discloses a broadband transient electromagnetic pulse signal acquisition device, comprising an electromagnetic pulse sensor, a collector with multiple acquisition channels in parallel, and a control end; the collector is provided with an acquisition processing unit, each of which includes a broadband operational amplifier, an analog-to-digital converter, and a DDR3 memory; the electromagnetic pulse sensor sends the electromagnetic induction pulse signal it collects to the broadband operational amplifier through a connector; the broadband operational amplifier converts the input single-ended signal into a differential signal, and sends it to the analog-to-digital converter for analog-to-digital conversion; then sends it to the acquisition processing unit, and the acquisition processing unit writes the electromagnetic pulse signal into the DDR3 memory of the acquisition channel; the control end issues a control command, receives the electromagnetic pulse data stored in the DDR3 through an optical fiber, and performs real-time waveform display and analysis. The acquisition device of the invention has multiple acquisition channels, each of which is independent and does not interfere with each other, has a wide acquisition frequency range characteristic from DC to 8GHz, fast transmission rate, and stable data.

Description

Technical Field

[0001] The invention belongs to the technical field of electromagnetic pulse signal acquisition devices and relates to a broadband transient electromagnetic pulse signal acquisition device. Background Art

[0002] In high-power electromagnetic environments such as high-altitude electromagnetic pulses, lightning electromagnetic pulses, ultra-wideband electromagnetic pulses, and narrowband high-power microwaves, interference or damage effects can be generated on various electronic systems. Therefore, many scholars are committed to studying the mechanism and laws of the effect to meet the needs of electromagnetic protection or effect evaluation. A large number of studies have shown that the use of pulse amplitude alone cannot fully characterize the physical mechanism of the electromagnetic pulse effect. Parameters such as the integrated energy of the pulse, the rate of change of the front edge, and the rectifier impact may all be sensitive parameters that cause the effect. In order to improve efficiency, people hope to be able to store and analyze the measured pulse signal after digitization, and quickly obtain the sensitive parameters that cause the effect. At the same time, in system-level effect tests, it is often necessary to measure the coupled field signal and the induced voltage and current signals in the closed cavity, which puts forward requirements for transient electromagnetic pulse signal acquisition equipment.

[0003] Existing electromagnetic pulse signal acquisition equipment can generally only collect and store medium and high frequency pulses, and cannot collect low frequency and ultra-high frequency pulse signals for large-capacity storage; it is easy to malfunction under ultra-strong electric fields, the collected waveform is easily distorted, and the collected data capacity is small. In addition, the existing equipment has only a single acquisition channel, which can only collect one sensor signal at a time, and cannot collect multiple sensor device signals at the same time; it is also impossible to display the pulse signal waveform in real time and intuitively. Summary of the invention

[0004] The problem solved by the present invention is to provide a broadband transient electromagnetic pulse signal acquisition device, which can acquire transient electromagnetic pulse signals from DC to ultra-high frequency in real time, perform large-capacity storage, and observe the electromagnetic pulse signal waveform in real time and intuitively.

[0005] The present invention is achieved through the following technical solutions:

[0006] A broadband transient electromagnetic pulse signal acquisition device comprises an electromagnetic pulse sensor, a collector with multiple acquisition channels in parallel, and a control terminal; the collector is provided with an acquisition processing unit, and each acquisition channel thereof comprises a broadband operational amplifier, an analog-to-digital converter, and a DDR3 memory;

[0007] The electromagnetic pulse sensor is provided with a receiving antenna, and the electromagnetic pulse sensor sends the electromagnetic induction pulse signal collected by the electromagnetic pulse sensor to the wide-band amplifier through a connector; the wide-band amplifier converts the input single-ended signal into a differential signal, and sends it to the analog-to-digital converter for analog-to-digital conversion; the electromagnetic pulse signal after the analog-to-digital conversion is sent to the acquisition processing unit through the analog-to-digital converter, and the acquisition processing unit writes the electromagnetic pulse signal into the DDR3 memory of the acquisition channel, and the DDR3 memory performs data cache;

[0008] The acquisition processing unit receives the control parameters sent by the control end, reads the electromagnetic pulse data from the DDR3 memory, and sends it to the control end through the optical fiber transmission port;

[0009] The control end receives the electromagnetic pulse data, stores it in a specified directory, analyzes the electromagnetic pulse data, and displays the electromagnetic pulse waveform obtained by the analysis.

[0010] The receiving antenna of the electromagnetic pulse sensor is a rod-shaped antenna, and a clamping voltage limiting circuit for limiting the electromagnetic induction pulse voltage is provided inside the electromagnetic pulse sensor; the output port of the electromagnetic pulse sensor is sent to the SMA connector of the acquisition channel via an SMA connector and a radio frequency line, and then to a broadband operational amplifier.

[0011] The broadband op amp is a differential op amp connected with a matching resistor so that its gain-bandwidth product is 8 GHz; the analog input bandwidth of the broadband op amp is 8 GHz, so that the acquisition channel has an analog bandwidth characteristic from DC to 8 GHz; the differential output of the broadband op amp has a standard EVM index and meets the input requirements of the analog-to-digital converter.

[0012] The matching resistors include an input impedance matching resistor and a gain amplifying resistor connected to the input end, and a differential output matching resistor connected to the output end;

[0013] The wideband op amp also features a common-mode reference input pin.

[0014] Furthermore, the acquisition processing unit controls the analog-to-digital converter to perform sampling by writing to the control register of the analog-to-digital converter, and its analog sampling bandwidth is 9 GHz; the acquisition processing unit controls each analog-to-digital converter at the same time, and the analog-to-digital converters are independent of each other;

[0015] The acquisition processing unit receives the data stream including the electromagnetic pulse signal sent by the analog-to-digital converter, performs flow control on the data stream, and sends the data stream to the corresponding DDR3 memory for storage and reading.

[0016] A parameter transmission port for bidirectional transmission of control parameters is provided between the collector and the control end. The control end can send control parameters to the collector. The control parameters sent by the control end include the trigger threshold of the electromagnetic pulse signal and the acquisition duration. The collector can also upload the working status parameters of each current acquisition channel to the control end, and the control end displays the working status parameters in real time.

[0017] The communication mode of the parameter transmission port includes:

[0018] The parameter transmission port is a serial communication interface suitable for short-distance communication. The serial communication interface transmits control parameters through a USB-to-serial data line;

[0019] Alternatively, the parameter transmission port is an optical fiber communication interface suitable for medium and long distance communications, and the optical fiber communication interface transmits control parameters through a dual-mode optical fiber line;

[0020] Alternatively, the parameter transmission port is a wireless communication interface suitable for long-distance communication, and the wireless communication interface transmits the control parameters through a wireless transmission module.

[0021] When the electromagnetic pulse signal quantized by the analog-to-digital converter received by the acquisition processing unit is greater than the set trigger threshold, the acquisition processing unit sends a trigger signal to the control end; the collector stores the electromagnetic pulse signal data for a period of time before the trigger moment and the electromagnetic pulse signal data for a period of time after the trigger moment;

[0022] After the control end obtains the trigger signal, it responds with an indication, and the trigger is completed;

[0023] After the trigger is completed, the collector collects electromagnetic pulse signals of corresponding duration according to the collection duration; after the collection is completed, the control end sends a data reading instruction, and the collector starts to upload electromagnetic pulse data after receiving the instruction; after receiving the electromagnetic pulse data, the control end analyzes it and displays the pulse waveform.

[0024] The control end parses the electromagnetic pulse data according to the data protocol: the control end receives 16 bytes of data each time until all electromagnetic pulse data are received; the control end splices the received 16 bytes of data into 10 points of electromagnetic pulse data, and the extra 8 bits of data are fixed to 0x00 when written and directly discarded;

[0025] After the control end completes the splicing of all electromagnetic pulse data points, it performs smoothing filtering and then displays the pulse waveform;

[0026] Alternatively, the control end converts all electromagnetic pulse data points into frequency domain, and after FFT transformation, calls the scatter plot control to display the waveform.

[0027] The control terminal also performs DC bias voltage calibration when displaying waveforms: the DC bias fixed value is subtracted from the original electromagnetic pulse data value to eliminate the DC bias component and calibrate the data;

[0028] The display duration of the pulse waveform is adjustable, and the maximum display duration does not exceed the total duration of the collector collecting the electromagnetic pulse signal.

[0029] Compared with the prior art, the present invention has the following beneficial technical effects:

[0030] The broadband transient electromagnetic pulse signal acquisition device provided by the present invention has independent acquisition channels of each collector and does not interfere with each other, and can simultaneously acquire signals of multiple sensor devices; it can acquire transient electromagnetic pulse signals from DC to ultra-high frequency (DC to 8GHz) in real time and perform large-capacity storage (total storage capacity can reach 8GB); the optical fiber transmission port can quickly transmit electromagnetic pulse signals (line rate is 6.25Gbps, and the maximum supported is 10.3125Gbps), the control end can observe the pulse signal waveform in real time and intuitively, and can also perform FFT analysis on the pulse signal.

[0031] The broadband transient electromagnetic pulse signal acquisition device provided by the present invention has a parameter transmission port for sending control parameters from the control end in various communication modes, and can use an optical fiber communication interface, a serial communication interface, and a wireless communication interface (4G) for transmission. It can be applied to different transmission distances and is easy to use; it is safer for users in high-voltage and strong magnetic environments.

[0032] The broadband transient electromagnetic pulse signal acquisition device provided by the present invention has multiple acquisition channels, each channel is independent and does not interfere with each other, the transmission rate is fast, and the data is stable; it can simultaneously acquire output signals of multiple sensor devices, such as electromagnetic induction voltage sensors, electromagnetic induction current sensors, electromagnetic induction field strength sensors, etc.; the acquisition device of the present invention can not only acquire electromagnetic pulse signals, but also acquire various forms of analog signals, such as sinusoidal signals and sinusoidal oscillation signals, and the acquisition frequency range is from DC to 8GHz. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the structure of the collector of the present invention;

[0034] Figure 2 The broadband operational amplifier matching circuit diagram of the present invention;

[0035] Figure 3 It is a schematic diagram of electromagnetic pulse transmission of the present invention;

[0036] Figure 4 It is a schematic diagram of the workflow of the present invention;

[0037] Figure 5 This is a schematic diagram of the display interface of the control terminal of the present invention;

[0038] Figure 6 The electromagnetic pulse waveform and spectrum diagram actually measured by the acquisition device of the present invention.

[0039] Among them: 1 is the first channel SMA connector, 2 is the second channel SMA connector, 3 is the third channel SMA connector, 4 is the fourth channel SMA connector, 5 is the optical fiber transmission port, 6 is the serial communication interface, 7 is the wireless communication interface, 8 is the rod antenna, 9 is the SMA connector, and 10 is the high-frequency radio frequency line. DETAILED DESCRIPTION

[0040] The present invention will be further described in detail below in conjunction with the accompanying drawings, which are intended to explain the present invention rather than to limit it.

[0041] See also Figure 1-Figure 5 , a broadband transient electromagnetic pulse signal acquisition device, comprising an electromagnetic pulse sensor, a collector with multiple acquisition channels in parallel and a control terminal; the collector is provided with an acquisition processing unit, each acquisition channel of which comprises a broadband operational amplifier, an analog-to-digital converter and a DDR3 memory;

[0042] The electromagnetic pulse sensor is provided with a receiving antenna, and the electromagnetic pulse sensor sends the electromagnetic induction pulse signal collected by the electromagnetic pulse sensor to the wide-band amplifier through a connector; the wide-band amplifier converts the input single-ended signal into a differential signal, and sends it to the analog-to-digital converter for analog-to-digital conversion; the electromagnetic pulse signal after the analog-to-digital conversion is sent to the acquisition processing unit through the analog-to-digital converter, and the acquisition processing unit writes the electromagnetic pulse signal into the DDR3 memory of the acquisition channel, and the DDR3 memory performs data cache;

[0043] The acquisition processing unit receives the control parameters sent by the control end, reads the electromagnetic pulse data from the DDR3 memory, and sends it to the control end through the optical fiber transmission port;

[0044] The control end receives the electromagnetic pulse data, stores it in a designated directory, analyzes the electromagnetic pulse data, and displays the electromagnetic pulse waveform obtained by the analysis.

[0045] The various devices and signal acquisition and processing of the present invention are described in detail below. The acquisition and processing unit is implemented based on Virtex®-7 series programmable FPGA chips, and the wideband operational amplifier is implemented based on LMH5401 differential amplifier.

[0046] The receiving antenna of the electromagnetic pulse sensor is a rod-shaped antenna, and a clamping voltage limiting circuit for limiting the electromagnetic induction pulse voltage is provided inside the electromagnetic pulse sensor; the output port of the electromagnetic pulse sensor is sent to the SMA connector of the acquisition channel via an SMA connector and a radio frequency line, and then to a broadband operational amplifier.

[0047] like Figure 1 As shown, the rod antenna 8 is the receiving antenna of the electromagnetic pulse sensor. The receiving antenna absorbs the electric field and magnetic field in the test site, causing charges to accumulate at both ends of the receiving antenna, forming an induced electromotive force, and generating an electromagnetic induction pulse voltage signal. Specifically, the rod antenna is 10 mm long and has a working bandwidth of 10 GHz.

[0048] The rod antenna is plugged into the input port of the electromagnetic pulse sensor. The electromagnetic pulse sensor is provided with a clamping voltage limiting circuit. The clamping voltage limiting circuit limits the electromagnetic induction pulse voltage value, and the output voltage value is ±1V. The output port of the electromagnetic pulse sensor is connected to the SMA connector 9, and the SMA connector outputs the electromagnetic induction pulse voltage. Specifically, the SMA connector can be a connector commonly used in the microwave field, and its bandwidth is 26.5GHz.

[0049] The SMA connector of the electromagnetic pulse sensor transmits the electromagnetic induction pulse signal to the SMA connector of each channel of the collector through the radio frequency line. The bandwidth of the radio frequency line is 12G, ensuring that the electromagnetic induction pulse signal will not be attenuated.

[0050] The collector is equipped with four acquisition channels, each of which is parallel, independent, and can work simultaneously without affecting each other; each acquisition channel is equipped with an SMA connector, a broadband operational amplifier, an analog-to-digital converter, and a DDR3 memory.

[0051] The broadband op amp is a differential op amp connected with a matching resistor so that its gain-bandwidth product is 8 GHz; the broadband op amp analog input bandwidth is 8 GHz, so that the acquisition channel has an analog bandwidth characteristic from DC to 8 GHz; the differential output of the broadband op amp has a standard EVM index and meets the input requirements of the analog-to-digital converter. The matching resistor includes an input impedance matching resistor and a gain amplification resistor connected to the input end, and a differential output matching resistor connected to the output end.

[0052] like Figure 2As shown, E2 is the single-ended analog input signal transmitted from the SMA connector and given to the LMH5401 op amp; R5 = 365Ω matches the SMA's own characteristic 50Ω input impedance (the SMA connector's own characteristic impedance is 50Ω); R6 = 175Ω and R8 = 22.6Ω, R16 = 66.5Ω and R8 = 175Ω determine that the amplification factor of LMH5401 is 2. Under the configuration of amplification factor of 2, the gain-bandwidth product of the LMH5401 op amp is 8GHz, which makes the op amp matching circuit have ultra-wideband characteristics and the analog input bandwidth is 8GHz.

[0053] The LMH5401 op amp is used in RF, IF or high-speed DC-coupled time domains and is very suitable for DC-coupled or AC-coupled applications. The LMH5401 op amp has very low second and third harmonic distortion when operating in single-ended to differential mode. The device provides a common-mode reference input pin so that the common-mode voltage of the amplifier output meets the ADC input requirements. The differential output matching resistors R9 = 40Ω and R13 = 40Ω of the LMH5401 give the differential output a standard EVM specification. The wideband op amp enables the collector to have an analog bandwidth characteristic from DC to 8GHz.

[0054] The acquisition processing unit controls the analog-to-digital converter to perform sampling by writing to the control register of the analog-to-digital converter, and its analog sampling bandwidth is 9 GHz; the acquisition processing unit controls each analog-to-digital converter at the same time, and the analog-to-digital converters are independent of each other; each acquisition channel can acquire electromagnetic pulse signals, sinusoidal analog signals or sinusoidal oscillation analog signals from DC to 8 GHz.

[0055] The acquisition processing unit receives the data stream including the electromagnetic pulse signal sent by the analog-to-digital converter, performs flow control on the data stream, and sends the data stream to the corresponding DDR3 memory for storage and reading.

[0056] Specifically, the differential outputs of each operational amplifier matching circuit are connected to the differential inputs of each analog-to-digital converter (specifically, a high-speed ADC with a sampling rate of 3Gsps), and the high-speed ADC performs analog-to-digital conversion. The acquisition processing unit (specifically, an FPGA chip) writes to the ADC control register by configuring the ADC's SPI pin to control the high-speed ADC for sampling. The analog sampling bandwidth of the ADC is 9GHz. The FPGA chip controls four ADCs at the same time, and the four ADCs are independent and run in parallel.

[0057] The electromagnetic pulse signal after ADC analog-to-digital conversion is connected to the FPGA chip through the ADC data pin. The FPGA chip receives the converted electromagnetic pulse data and controls the high-speed data stream, sending the high-speed data stream to DDR3 for storage and reading. FPGA configures the command register of DDR3 by controlling the command pin and data pin of DDR3. The electromagnetic pulse data is written to DDR3, and DDR3 caches the data. The FPGA chip controls four DDR3s at the same time, and the four DDR3s are independent and write data in parallel.

[0058] Each DDR3 group is independent, and the total capacity of 4 DDR3 groups is 8GB. The throughput of each DDR3 group can reach 12.8GB / s. Each DDR3 group can store 100ms pulse signals, with a storage depth of 500MB, and the maximum storage depth can be expanded to 2GB.

[0059] The FPGA chip receives the read electromagnetic pulse data and sends the electromagnetic pulse data to the optical fiber transmission port. The optical fiber transmission interface is connected to the Gigabit SFP optical fiber transceiver through an optical fiber line, and the Gigabit SFP optical fiber transceiver sends the data to the control end (host computer) through a network cable. Specifically, the optical fiber transmission port line rate is 6.25Gbps, and the maximum supported is 10.3125Gbps; the bandwidth is 1000Mb / s, and the real-time stable transmission rate is up to 85MB / s.

[0060] A parameter transmission port for bidirectional transmission of control parameters is provided between the collector and the control end. The control end can send control parameters to the collector. The control parameters sent by the control end include the trigger threshold of the electromagnetic pulse signal and the acquisition duration. The collector can also upload the working status parameters of each current acquisition channel to the control end, and the control end displays the working status parameters in real time.

[0061] Specifically, parameters such as the collector's trigger threshold and the acquisition duration of the electromagnetic pulse signal can be freely configured through the host computer. Users can set different control parameters and send them to the collector according to their different needs. The host computer can also receive the current working status parameters of the hardware uploaded by the collector and display them in real time. Based on these parameters, users can understand whether the current collector is in normal working condition.

[0062] Taking into account the application environment of the collector is an ultra-high voltage and strong magnetic environment, and for the safety of testers and ease of use, the collector is equipped with three optional communication modes for parameter transmission ports and three optional communication modes; different solutions are used for different experimental environments.

[0063] The communication modes of the parameter transmission port include:

[0064] The parameter transmission port is a serial communication interface (16 groups of 422 serial ports) suitable for short-distance communication. The serial communication interface transmits electromagnetic pulse control parameters through a USB-to-serial data line;

[0065] Alternatively, the parameter transmission port is an optical fiber communication interface suitable for medium and long distance communication, and the optical fiber communication interface transmits electromagnetic pulse control parameters through a dual-mode optical fiber line;

[0066] Alternatively, the parameter transmission port is a wireless communication interface suitable for long-distance communication, and the wireless communication interface transmits the electromagnetic pulse control parameters through a wireless transmission module.

[0067] Specifically, when serial communication is selected, the FPGA chip sends a read instruction to DDR3 through the serial port pin after receiving the control parameters of the host computer, and reads the electromagnetic pulse data from DDR3.

[0068] like Figure 4 As shown, when the quantized value of the electromagnetic pulse signal quantized by the analog-to-digital converter received by the acquisition processing unit is greater than the set trigger threshold, the acquisition processing unit sends a trigger signal to the control end; the collector stores the electromagnetic pulse signal data for a period of time before the trigger moment and the electromagnetic pulse signal data for a period of time after the trigger moment;

[0069] After the control end obtains the trigger signal, it responds with an indication, and the trigger is completed;

[0070] After the trigger is completed, the collector collects electromagnetic pulse signals of corresponding duration according to the collection duration; after the collection is completed, the control end sends a data reading instruction, and the collector starts to upload electromagnetic pulse data after receiving the instruction; after receiving the electromagnetic pulse data, the control end analyzes it and displays the pulse waveform.

[0071] The control end parses the electromagnetic pulse data according to the data protocol: the control end receives 16 bytes of data each time until all electromagnetic pulse data are received; the control end splices the received 16 bytes of data into 10 points of electromagnetic pulse data, and the extra 8 bits of data are fixed to 0x00 when written and directly discarded;

[0072] After the control end completes the splicing of all electromagnetic pulse data points, it performs smoothing filtering and then displays the pulse waveform;

[0073] Alternatively, the control end converts all electromagnetic pulse data points into frequency domain, and after FFT transformation, calls the scatter plot control to display the waveform.

[0074] Specifically, the host computer receives 16 bytes of data each time until all the data is received. Since one data point of electromagnetic pulse data is 12 bits, the host computer splices the received 16 bytes of data. The 16 bytes of data are spliced ​​into 10 points of electromagnetic pulse data. The extra 8 bits of data are fixed to 0x00 when written, so they can be directly discarded.

[0075] After the host computer completes the splicing of all electromagnetic pulse data points, it performs smoothing filtering. The smoothing filtering algorithm is shown in the following formula (1.1):

[0076]

[0077] Where X i is the electromagnetic pulse data point, X V is the electromagnetic pulse data point after the smoothing filter algorithm is processed. i and v are the data point numbers, and the maximum value of i and v is 5 million. Every 3 adjacent electromagnetic pulse data points are added and divided by 3 to complete the base 3 smoothing filter algorithm processing. After all electromagnetic pulse data points are processed by the smoothing algorithm, the scatter plot control is called to display the waveform. The horizontal axis of the graph is the data point number, and the vertical axis is the electromagnetic pulse data value after smoothing filtering.

[0078] The host computer can perform frequency domain conversion processing on the electromagnetic pulse data and convert the time domain data into frequency domain data. The host computer performs multi-point fast Fourier transform (FFT) on the pulse data according to the fast Fourier transform algorithm, and the transformation point order can reach millions. For the converted frequency domain data, the host computer can display it graphically and intuitively view the spectrum diagram after FFT transformation. This makes it convenient for users to quickly obtain the spectrum characteristics of the electromagnetic pulse signal, so as to extract the electromagnetic norm required for electromagnetic pulse signal analysis.

[0079] Specifically, when performing FFT analysis, the host computer supports the selection of a variable number of data points. The user can freely set the number of data points to be transformed by FFT to obtain spectrum diagrams in different frequency domain intervals. The maximum number of data points supported is up to 5 million data points.

[0080] The FFT algorithm used in the frequency domain conversion process is shown in the following formula (1.2-1.5):

[0081]

[0082]

[0083]

[0084]

[0085] Where X(2r) and X(2r+1) are electromagnetic pulse data points, r is the data sequence number, W is the butterfly rotation factor, X(k) and It is the frequency domain value after FFT transformation. After the host computer performs FFT transformation on all electromagnetic pulse data points, the host computer calls the scatter plot control to display the waveform. The horizontal axis of the graph is the frequency, and the vertical axis is the frequency domain value of the corresponding frequency point.

[0086] Since the collected pulse signal may be affected by the DC bias voltage, the control end also performs DC bias voltage calibration for the convenience of users. After actual measurement, the measurement results are analyzed mathematically and statistically, and the conclusion is that the DC bias of each channel is an approximate fixed value with an error range of 0.1%. Therefore, DC bias voltage calibration is to subtract the DC bias fixed value (which can be measured) from the original data value to eliminate the DC bias component of the original data and calibrate the data. The 4 acquisition channels are independent and can be calibrated separately according to actual conditions.

[0087] The display time of the pulse waveform is adjustable, and the user can freely set the display time; the maximum display time does not exceed the total time of the collector collecting the electromagnetic pulse signal.

[0088] A specific embodiment of electromagnetic pulse signal acquisition is given below.

[0089] like Figure 3 , Figure 4 As shown in the figure, after the collector is powered on, the host computer sends control parameters through the serial port or optical port. The control parameters include trigger threshold, acquisition length, etc. For example, when the actual amplitude of the electromagnetic induction pulse signal is 800mv, the trigger threshold can be set to 400mv. As long as the trigger threshold is less than 800mv, it is a reasonable threshold. After receiving the control parameters, the collector starts waiting for the electromagnetic induction pulse signal.

[0090] The 4 independent electromagnetic pulse sensors will collect electromagnetic induction signals and send them to 4 independent high-speed ADCs in parallel. After the 4 high-speed ADCs perform analog-to-digital conversion, they will send high-speed data streams to the FPGA chip at the same time. The FPGA chip sends data to 4 DDR3s for caching at the same time. After the caching is completed. The FPGA chip reads data from the DDR3 in order from small to large according to the given number. When the electromagnetic induction pulse signal value quantified by the ADC received by the FPGA chip is greater than the set trigger threshold received by the FPGA chip, the FPGA will give a high-level trigger signal and send it to the host computer through the J30J-zkp35 connection line.

[0091] After the trigger signal is obtained, the trigger indicator of the host computer changes from green to yellow, indicating that the trigger is completed; after the trigger is completed, the collector starts to collect electromagnetic induction pulse signals of the corresponding duration according to the collection duration issued by the host computer. After the collection is completed, the host computer issues a data reading instruction, and the collector starts to upload data after receiving the instruction. After the host computer receives all the data, it can display the data waveform and perform frequency domain conversion.

[0092] like Figure 5 The upper computer user interface shown in the figure shows that the top 4 indicator lights are respectively the indicator lights for whether the 4 acquisition channels are triggered, and the 4 channels are independent of each other. It is green when not triggered and yellow after the trigger is completed. Below the indicator lights are some configuration parameters of the serial port and the network port, which can be configured with the serial port number, baud rate, data bit, check bit, stop bit, local IP number, local port, transmission speed, etc. After the configuration is completed, the configuration buttons for opening the serial port and connecting the network port are respectively below; below them are the configuration selection boxes for the trigger threshold, trigger front edge and trigger length, which can be configured according to actual needs. The data storage path can be freely selected. After completing the selection, click the configuration button below, and all configuration parameters will be sent to the collector. At the bottom, there are the start acquisition and read data buttons. After clicking the start acquisition button, the acquisition board receives the command and starts waiting.

[0093] When the green indicator light of a channel turns yellow, it means that the channel has completed the trigger. At this time, you can click to read the data. After the data reading is completed, click Stop reading data to stop the acquisition. This means that one acquisition is completed, and then the data can be displayed and FFT analysis can be performed.

[0094] like Figure 6 As shown in the figure, in the actual standard lightning wave high voltage test, the real-time waveform and spectrum of the electromagnetic induction pulse displayed by the host computer. The test conditions of the standard lightning wave high voltage test are: the electric field strength is 500KV / m, and the electromagnetic pulse sensor and collector are 100 meters away from the impulse voltage generator. From the waveform diagram, it can be seen that the peak-to-peak voltage of the electromagnetic induction pulse after attenuation is 350mv, and the acquisition time is 20ms. The frequency domain value of each frequency point of the electromagnetic induction pulse is shown in the spectrum diagram. The integrated energy, leading edge change rate, rectification impulse and other parameters of the electromagnetic induction pulse can be obtained through the data provided by the spectrum diagram and waveform diagram.

[0095] The above embodiments are preferred examples for implementing the present invention, and the present invention is not limited to the above embodiments. Any non-essential additions and substitutions made by those skilled in the art based on the technical features of the technical solution of the present invention shall fall within the protection scope of the present invention.

Claims

1. A broadband transient electromagnetic pulse signal acquisition device, characterized in that: It includes an electromagnetic pulse sensor, a collector with multiple parallel collection channels and a control terminal; the collector is provided with a collection processing unit, and each collection channel thereof includes a broadband operational amplifier, an analog-to-digital converter and a DDR3 memory; The electromagnetic pulse sensor is provided with a receiving antenna, and the electromagnetic pulse sensor sends the electromagnetic induction pulse signal collected by it to the wide-band operational amplifier through a connector; the wide-band operational amplifier converts the input single-ended signal into a differential signal, and sends it to the analog-to-digital converter for analog-to-digital conversion; The electromagnetic pulse signal after analog-to-digital conversion is sent to the acquisition processing unit through the analog-to-digital converter. The acquisition processing unit writes the electromagnetic pulse signal into the DDR3 memory of the acquisition channel, and the DDR3 memory performs data buffering. The broadband operational amplifier is a differential operational amplifier LMH5401 connected with a matching resistor, the gain factor of the differential operational amplifier is 2, and its gain bandwidth product is 8GHz; the matching resistor includes an input impedance matching resistor connected to the input end, a gain amplification resistor, and a differential output matching resistor connected to the output end; The input impedance matching resistor is 50Ω; the gain amplification resistor includes R6 and R8 connected between the input terminal and FB+, and R16 and R15 between the ground and FB-, wherein R6=175Ω, R8=22.6Ω, R16=66.5Ω, R15=175Ω; the differential output matching resistor is 40Ω; When the quantized value of the electromagnetic pulse signal quantized by the analog-to-digital converter received by the acquisition processing unit is greater than the set trigger threshold, the acquisition processing unit sends a trigger signal to the control end; after the control end obtains the trigger signal, it responds with an indication, and the trigger is completed; after the trigger is completed, the collector collects the electromagnetic pulse signal of the corresponding duration according to the acquisition duration; The acquisition processing unit receives the control parameters sent by the control end, reads the electromagnetic pulse data from the DDR3 memory, and sends it to the control end through the optical fiber transmission port; The control end receives the electromagnetic pulse data, stores it in a designated directory, analyzes the electromagnetic pulse data, and displays the electromagnetic pulse waveform obtained by the analysis; The collector stores electromagnetic pulse signal data for a period of time before the triggering moment and electromagnetic pulse signal data for a period of time after the triggering moment; After the acquisition is completed, the control end sends a data reading instruction, and the collector starts uploading the electromagnetic pulse data after receiving the instruction; the control end analyzes the electromagnetic pulse data after receiving it; The control end parses the electromagnetic pulse data according to the data protocol: the control end receives 16 bytes of data each time until all electromagnetic pulse data are received; the control end splices the received 16 bytes of data into 10 points of electromagnetic pulse data, and the extra 8 bits of data are fixed to 0x00 when written and directly discarded; After the control end completes the splicing of all electromagnetic pulse data points, it performs smoothing filtering and then displays the pulse waveform; Alternatively, the control end performs frequency domain conversion on all electromagnetic pulse data points, and after FFT transformation, calls the scatter plot control to display the waveform; The control terminal also performs DC bias voltage calibration when displaying waveforms: the DC bias fixed value is subtracted from the original electromagnetic pulse data value to eliminate the DC bias component and calibrate the data; The display duration of the pulse waveform is adjustable, and the maximum display duration does not exceed the total duration of the collector collecting the electromagnetic pulse signal.

2. The broadband transient electromagnetic pulse signal acquisition device according to claim 1, characterized in that: The receiving antenna of the electromagnetic pulse sensor is a rod-shaped antenna, and a clamping voltage limiting circuit for limiting the electromagnetic induction pulse voltage is provided inside the electromagnetic pulse sensor; the output port of the electromagnetic pulse sensor is sent to the SMA connector of the acquisition channel via an SMA connector and a radio frequency line, and then to a broadband operational amplifier.

3. The broadband transient electromagnetic pulse signal acquisition device according to claim 1, characterized in that: The analog input bandwidth of the wideband op amp is 8 GHz, which enables the acquisition channel to have an analog bandwidth characteristic from DC to 8 GHz; the differential output of the wideband op amp has a standard EVM index and meets the input requirements of the analog-to-digital converter.

4. The broadband transient electromagnetic pulse signal acquisition device according to claim 3, characterized in that: The wideband op amp also features a common-mode reference input pin.

5. The broadband transient electromagnetic pulse signal acquisition device according to claim 1, characterized in that: The acquisition processing unit controls the analog-to-digital converter to perform sampling by writing into the control register of the analog-to-digital converter, and its analog sampling bandwidth is 9 GHz; the acquisition processing unit controls each analog-to-digital converter at the same time, and the analog-to-digital converters are independent of each other; The acquisition processing unit receives the data stream including the electromagnetic pulse signal sent by the analog-to-digital converter, performs flow control on the data stream, and sends the data stream to the corresponding DDR3 memory for storage and reading.

6. The broadband transient electromagnetic pulse signal acquisition device according to claim 1, characterized in that: A parameter transmission port for bidirectional transmission of control parameters is provided between the collector and the control end. The control end can send control parameters to the collector. The control parameters sent by the control end include the trigger threshold of the electromagnetic pulse signal and the acquisition duration. The collector can also upload the working status parameters of each current acquisition channel to the control end, and the control end displays the working status parameters in real time. The communication mode of the parameter transmission port includes: The parameter transmission port is a serial communication interface suitable for short-distance communication. The serial communication interface transmits control parameters through a USB-to-serial data line; Alternatively, the parameter transmission port is an optical fiber communication interface suitable for medium and long distance communications, and the optical fiber communication interface transmits control parameters through a dual-mode optical fiber line; Alternatively, the parameter transmission port is a wireless communication interface suitable for long-distance communication, and the wireless communication interface transmits the control parameters through a wireless transmission module.

7. The broadband transient electromagnetic pulse signal acquisition device according to claim 1, 3, 5 or 6, characterized in that: The acquisition processing unit is implemented based on an FPGA chip, and the broadband operational amplifier is implemented based on an LMH5401 differential amplifier; the DDR3 memory can store 100ms electromagnetic pulse signals, with a storage depth of 500MB, and the maximum storage depth can be expanded to 2GB; Each acquisition channel can collect electromagnetic pulse signals, sinusoidal analog signals or sinusoidal oscillation analog signals from DC to 8GHz; The optical fiber transmission port of the collector sends electromagnetic pulse data to the control end through an optical fiber line. The line rate of the optical fiber transmission port is 6.25Gbps and supports a maximum of 10.3125Gbps; the bandwidth is 1000Mb / s, and the real-time stable transmission rate is up to 85MB / s.

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