Microwave spectrum acquisition and processing system based on FPGA (Field Programmable Gate Array) and working method of microwave spectrum acquisition and processing system

Abstract

The invention discloses a microwave spectrum acquisition and processing system based on an FPGA (Field Programmable Gate Array) and a working method of the microwave spectrum acquisition and processing system. According to the scheme, the FID signal acquisition module carries out ADC acquisition on excited FID signals, FID analog signals are converted into digital signals, data bit width conversion and speed reduction are carried out through the FPGA-based core control module, and then the digital signals are stored in the memory module; and the cached FID data enters the data transmission module through the FPGA-based core control module and is transmitted to the upper computer analysis module for final data processing and analysis. On the premise that the high signal-to-noise ratio is guaranteed, integration of FID signal collection, storage, transmission and analysis is achieved, the integration level and operation efficiency of the spectrometer are greatly improved, the instrument building cost is reduced, the equipment size is reduced, and the scene applicability is enhanced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of microwave spectrum detection and data acquisition, and particularly relates to a microwave spectrum acquisition and processing system based on FPGA and a working method thereof. BACKGROUND

[0002] The detection of rotational spectrum is mainly aimed at gas-phase molecules, and is an important tool for studying molecular dynamics, molecular structure, and interstellar medium molecular detection. As a key device for measuring molecular rotational transition, the microwave spectrometer is increasingly widely used in physical chemistry and molecular astrophysics with the development of laboratory technology.

[0003] Although the current chirped pulse-FTMW (CP-FTMW) instrument has gradually become popular, there are obvious shortcomings in FID signal acquisition. The traditional ADC acquisition control adopts a discrete timing control circuit, and the sampling synchronization is poor. Moreover, the data transmission relies on a single channel, which cannot match the high-speed acquisition demand of the wideband FID signal, and data flow interruption is prone to occur. There is a lack of efficient local storage mechanism, and data uploading directly is prone to cause lag due to transmission bandwidth limitation, thereby affecting the real-time performance of spectral analysis. The acquisition and analysis processes are separated, and the FPGA is only used as an auxiliary control unit, and the parallel processing advantage of the FPGA is not fully utilized. These problems result in large instrument size, poor flexibility, high cost, and limit the popularization of molecular rotational spectrum measurement. Therefore, the integration, wideband, and high efficiency of the spectrometer are the main trends in this field. SUMMARY

[0004] The application aims to provide a microwave spectrum acquisition and processing system based on FPGA and a working method thereof, which realizes the integrated integration of FID signal acquisition, storage, transmission and analysis, greatly improves the integration and operation efficiency of the spectrometer, reduces the instrument construction cost, reduces the equipment size, and enhances the scene applicability.

[0005] In order to achieve the purpose of the application, on the one hand, the application provides a microwave spectrum acquisition and processing system based on FPGA, which comprises the following modules:

[0006] The FID signal acquisition module is used for converting the FID analog signal into a digital signal through an ADC acquisition card, and transmitting the digital signal to the FPGA-based core control module;

[0007] The FPGA-based core control module is used for realizing the timing control of the FID signal acquisition module, the storage scheduling of the memory module, and the protocol adaptation of the data transmission module, and uniformly coordinating the work of each module;

[0008] The memory module is used for temporarily buffering the data collected by the FID signal acquisition module, and realizing the read-write separation of acquisition and uploading;

[0009] The data transmission module is used to communicate with the host computer analysis module and upload the data cached by the memory module to the host computer at high speed.

[0010] The host computer analysis module is used to receive FID data and perform FFT transformation to generate molecular rotation spectrum information.

[0011] On the other hand, the present invention also provides a working method for an FPGA-based microwave spectral acquisition and processing system, comprising the following steps:

[0012] Step 1: Complete the system power-on reset and initialize each functional module of the FPGA through the internal initialization logic of the FPGA.

[0013] Step 2: Using the initialized FPGA as the control core, set the sampling parameters through configuration instructions to synchronously determine the initial write address and read address of the DDR3 memory module;

[0014] Step 3: Send the configured sampling parameters to the FID signal acquisition module, and write the raw data acquired by the ADC to the DDR3 storage module for caching through the FPGA's high-speed interface;

[0015] Step 4: Using the data written to DDR3 as the monitoring object, obtain the real-time storage status of DDR3 through the storage status monitoring logic of the FPGA;

[0016] Step 5: Compare the obtained storage status with the preset threshold to determine whether the data storage amount has reached the preset threshold; if the comparison result is negative, return to step 3 to continue writing data to DDR3; if the comparison result is positive, proceed to the next step.

[0017] Step 6: Upload the DDR3 cache data that has reached the threshold to the host computer via a high-speed USB transmission link;

[0018] Step 7: Process and analyze the uploaded host computer data using a spectral analysis algorithm.

[0019] Compared with the prior art, the significant advancements of this invention are: 1) This invention adopts a highly integrated module and FPGA co-design to replace traditional discrete devices and large instruments, greatly reducing the system size, lowering the construction cost, and improving operational flexibility; 2) This invention uses a DDR3 storage module to achieve high-speed data caching, and in conjunction with the USB 3.0 transmission protocol, avoids data loss when collecting large amounts of data, and improves transmission efficiency.

[0020] To more clearly illustrate the functional characteristics and structural parameters of the present invention, further explanation is provided below in conjunction with the accompanying drawings and specific embodiments. Attached Figure Description

[0021] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0022] Figure 1 This is a schematic diagram of the FPGA-based microwave spectrum acquisition and processing system of the present invention;

[0023] Figure 2 This is a flowchart of the working method steps of the present invention;

[0024] Figure 3 This is a schematic diagram of the acquisition and reconstruction of a 10MHz_0.5Vpp sine wave according to the present invention;

[0025] Figure 4 This is a spectral data diagram of OCS molecules collected in the 12.12-12.18 GHz frequency band in an embodiment of the present invention. Detailed Implementation

[0026] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] This invention provides an FPGA-based microwave spectrum acquisition and processing system, combined with... Figure 1 It includes the following modules:

[0028] FID signal acquisition module A is used to convert FID analog signals into digital signals through an ADC acquisition card and transmit them to the FPGA-based core control module B.

[0029] The FPGA-based core control module B is used to implement the timing control of the FID signal acquisition module A, the storage scheduling of the memory module C, and the protocol adaptation of the data transmission module D, and to coordinate the work of each module in a unified manner.

[0030] The memory module C is used to temporarily cache the data collected by the FID signal acquisition module A, so as to realize the separation of reading and writing for acquisition and uploading;

[0031] The data transmission module D is used to communicate with the host computer analysis module E and to upload the data cached by the memory module C to the host computer at high speed.

[0032] The host computer analysis module E is used to receive FID data and perform FFT transformation processing to generate molecular rotation spectrum information.

[0033] Furthermore, the FID signal acquisition module A acquires the excited FID signal using an ADC, converting the FID analog signal into a digital signal. After data bit width conversion and speed reduction by the FPGA-based core control module B, the data is stored in the memory module C. The cached FID data is transmitted to the host computer analysis module E through the data transmission module D via the FPGA-based core control module B for final data processing and analysis.

[0034] Furthermore, the FID signal acquisition module A uses an LS08D2000 ADC acquisition board, which supports dual channels, a sampling rate of 1.0 GSa / s, and a maximum bandwidth of 500 MHz, and achieves high-speed synchronous acquisition of the preprocessed FID signal under FPGA control.

[0035] Furthermore, the FPGA-based core control module B uses a Xilinx Artix-7 series FPGA chip as its main control chip, which is connected to the ADC acquisition card LS08D2000 through an LVDS interface to achieve high-speed data transmission and control signal interaction.

[0036] Furthermore, the FPGA-based core control module B is specifically designed as follows: the FPGA-based PCB motherboard and the function board LS08D2000 are connected via an FMC connector, and connected to DDR3 and USB via connectors. The function board can be controlled by outputting LVCMOS level signals from the FPGA. The power supply for the FID signal acquisition module A, memory module C, and data transmission module D is provided by the power supply designed for the FPGA-based PCB motherboard.

[0037] Furthermore, the memory module C uses Nanya DDR3 chips NT5CB128M16IP-DI with a capacity of ≥2GB, and is connected to the FPGA via a high-speed bus to achieve fast data reading and writing.

[0038] Furthermore, the data transmission module D uses a CYUSB3014 USB chip to achieve USB 3.0 protocol adaptation, ensuring continuous transmission of large amounts of data without lag.

[0039] Furthermore, the host computer analysis module E is specifically designed with a LabVIEW program for data acquisition and reception, and Matlab for data processing and analysis.

[0040] The various functional modules in the system are uniformly controlled and coordinated by pulse control signals output from the FPGA development board to achieve functional synchronization.

[0041] Based on the above-described working method of an FPGA-based microwave spectrum acquisition and processing system, combined with Figure 2 This includes the following steps:

[0042] Step 1: Complete the system power-on reset and initialize each functional module of the FPGA through the internal initialization logic of the FPGA.

[0043] Step 2: Using the initialized FPGA as the control core, set the sampling parameters through configuration instructions to synchronously determine the initial write address and read address of the DDR3 memory module;

[0044] Step 3: Send the configured sampling parameters to the FID signal acquisition module, and write the raw data acquired by the ADC to the DDR3 storage module for caching through the FPGA's high-speed interface;

[0045] Step 4: Using the data written to DDR3 as the monitoring object, obtain the real-time storage status of DDR3 through the storage status monitoring logic of the FPGA;

[0046] Step 5: Compare the obtained storage status with the preset threshold to determine whether the data storage amount has reached the preset threshold; if the comparison result is negative, return to step 3 to continue writing data to DDR3; if the comparison result is positive, proceed to the next step.

[0047] Step 6: Upload the DDR3 cache data that has reached the threshold to the host computer via a high-speed USB transmission link;

[0048] Step 7: Process and analyze the uploaded host computer data using a spectral analysis algorithm.

[0049] To verify the system's data acquisition and transmission performance, the functions of the ADC acquisition module and DDR3 storage module were verified through continuous sampling tests under FPGA control. Test data shows that the system can stably achieve a sampling rate of 400MS / s, the DDR3 storage module can continuously cache large amounts of data, and the USB 3.0 transmission module exhibits no data loss, ensuring the reliability of data acquisition and transmission.

[0050] To verify the performance of the microwave spectral acquisition system, a 10MHz signal was acquired at a sampling rate of 400MS / s. According to the input requirements of the FID signal acquisition module A, a signal generator was used to provide a sinusoidal signal with a frequency of 10MHz and an amplitude of 500mV to the FID signal acquisition module A. The acquisition function of the host computer analysis module E was then activated to acquire and save the data. The acquired data was then reproduced as a waveform. Figure 3 The obtained data shows that the collected data restored the original signal, and the FFT transformation verified the correctness of the input signal frequency.

[0051] In summary, the FPGA-based microwave spectral acquisition and processing system provided by this invention achieves integrated FID signal acquisition, storage, transmission and analysis while ensuring a high signal-to-noise ratio. It can quickly complete wide-band spectral detection, improve the integration and operating efficiency of the spectrometer, reduce instrument costs, and has broad application prospects.

[0052] Example

[0053] The effectiveness of the FPGA-based microwave spectral acquisition and processing system of this invention was experimentally verified. The samples used in the experiment were carbonyl sulfide (OCS) and its isotopic substituted products, and the selected frequency band was 12.12-12.18 GHz, and their molecular rotation spectra were detected. Figure 4 As shown, the frequency error of the spectral lines is approximately 100 kHz, and the accuracy is consistent with similar large-scale equipment. Therefore, the FPGA-based microwave spectral acquisition and processing system of this invention can be used for rotational spectral measurement of matter molecules and has high detection accuracy.

[0054] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0055] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A FPGA-based microwave spectrum acquisition and processing system, characterized in that, The application relates to a FID signal acquisition system, which comprises the following modules: An FID signal acquisition module (A) is used for converting an FID analog signal into a digital signal through an ADC acquisition card and transmitting the digital signal to a core control module (B) based on FPGA; The core control module (B) based on FPGA is used for realizing timing control of the FID signal acquisition module (A), storage scheduling of a memory module (C) and protocol adaptation of a data transmission module (D) and uniformly coordinating work of the modules; The memory module (C) is used for temporarily buffering data collected by the FID signal acquisition module (A), realizing read-write separation of collection and uploading; The data transmission module (D) is used for communicating with an upper computer analysis module (E) and uploading data buffered by the memory module (C) to the upper computer at high speed; The upper computer analysis module (E) is used for receiving FID data and performing FFT transformation processing to generate molecular rotation spectrum information.

2. The FPGA-based microwave spectrum acquisition and processing system of claim 1, wherein, The FID signal acquisition module (A) converts an FID analog signal into a digital signal through ADC collection of an FID signal after excitation, performs data bit width conversion and speed reduction through the core control module (B) based on FPGA, stores the FID data in the memory module (C), and transmits the buffered FID data to the upper computer analysis module (E) through the data transmission module (D) based on FPGA to perform final data processing and analysis.

3. The FPGA-based microwave spectrum acquisition and processing system of claim 1, wherein, The FID signal acquisition module (A) adopts a data acquisition card with a model number of LS08D2000.

4. The FPGA-based microwave spectrum acquisition and processing system of claim 1, wherein, The core control module (B) based on FPGA adopts an FPGA chip with a model number of Xilinx Artix-7.

5. The FPGA-based microwave spectrum acquisition and processing system of claim 1, wherein, The core control module (B) based on FPGA is specifically: a PCB mainboard based on FPGA is connected with a functional board LS08D2000 through an FMC connector, connected with DDR3 and USB through connectors, and can realize control of the functional board through FPGA output of an LVCMOS level signal.

6. The FPGA-based microwave spectrum acquisition and processing system of claim 1, wherein, The memory module (C) adopts a South Asia DDR3 particle NT5CB128M16IP-DI.

7. The FPGA-based microwave spectrum acquisition and processing system of claim 1, wherein, The data transmission module (D) adopts a USB with a model number of CYUSB3014.

8. The FPGA-based microwave spectrum acquisition and processing system of claim 1, wherein, The upper computer analysis module (E) is specifically programmed by Labview to perform data collection and reception and by Matlab to perform data processing and analysis.

9. The working method of the FPGA-based microwave spectrum acquisition and processing system according to any one of claims 1-8, characterized in that, The application further relates to a method for controlling the FID signal acquisition system, which comprises the following steps: Step 1: completing system power-on reset, realizing initialization of all functional modules of FPGA through internal initialization logic of the FPGA; Step 2: taking the initialized FPGA as a control core, setting sampling parameters through configuration instructions, and synchronously determining initial write and read addresses of a DDR3 storage module; Step 3: issuing the configured sampling parameters to the FID signal acquisition module, and writing original data collected by the ADC into the DDR3 storage module for buffering through a high-speed interface of the FPGA; Step 4, the data written in DDR3 is taken as a monitoring object, and the real-time storage state of DDR3 is obtained through the storage state monitoring logic of FPGA; Step 5, the obtained storage state is compared with a preset threshold value to determine whether the data storage amount reaches the preset threshold value; If the comparison result is no, return to step 3 to continue writing data into DDR3; If the comparison result is yes, proceed to the next step; Step 6, the DDR3 cache data reaching the threshold value is uploaded to the upper computer through the USB high-speed transmission link; Step 7, the uploaded upper computer data is processed and analyzed through a spectrum analysis algorithm.

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