X-band MIMO system flue-cured tobacco strip box radar detection device

Abstract

The utility model provides an X-band MIMO (Multiple Input Multiple Output) system strip tobacco box radar detection device, which solves the problems of insufficient detection precision of the water content of tobacco leaves and the like, and comprises an intermediate frequency signal acquisition and control unit connected with a broadband linear frequency modulation signal generation unit, the broadband linear frequency modulation signal generation unit is connected with a transmit-receive antenna array unit, and the transmit-receive antenna array unit is connected with the frequency mixing receiving unit. The device has the advantages of high detection precision, good adaptability and the like.

Description

Technical Field

[0001] This utility model belongs to the field of tobacco leaf detection technology, specifically relating to an X-band MIMO system tobacco leaf box radar detection device. Background Technology

[0002] Currently, mature products both domestically and internationally all use a single point frequency signal for detection. The analysis of moisture content is based on the amplitude information of microwave signal transmission or reflection to estimate the moisture content of the measured item. Since it is based only on the amplitude information of the echo signal, the measurement accuracy is not high, and the measurement process is based on mechanical motion to complete the measurement process, resulting in low efficiency in measuring moisture content.

[0003] To address the shortcomings of existing technologies, people have conducted long-term explorations and proposed various solutions. For example, Chinese patent literature discloses a method for characterizing the style characteristics of individual tobacco leaves based on aroma components [201110022023.9]. The method is as follows: a. Use radar charts to compare and analyze the aroma characteristics of various varieties. In a radar chart, each data point has an independent single numerical axis, and the coordinate axes are radially distributed around the center point. Connecting the points of the same data sequence values ​​on different coordinate axes with broken lines forms a polygon, which is used to compare the overall situation of several data sequence indicators; b. Detect the aroma components of different varieties in the same region, and then conduct multiple comparisons of the aroma component content to examine the differences between treatments—between each variety and other varieties, eliminate insignificant indicators, and find the material basis for the aroma differences between varieties from the perspective of aroma substance content.

[0004] The above-mentioned scheme has solved the problem of detecting the style characteristics of tobacco leaves to a certain extent, but it still has many shortcomings, such as insufficient accuracy in detecting the moisture content of tobacco leaves. Summary of the Invention

[0005] The purpose of this invention is to address the above-mentioned problems by providing a reasonably designed X-band MIMO system sheet smoke box radar detection device with high detection accuracy.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: an X-band MIMO system film smoke box radar detection device, comprising an intermediate frequency signal acquisition and control unit, the intermediate frequency signal acquisition and control unit being connected to a broadband linear frequency modulation signal generation unit, the broadband linear frequency modulation signal generation unit being connected to a transceiver antenna array unit, and the transceiver antenna array unit being connected to a mixing receiver unit.

[0007] In the aforementioned X-band MIMO system sheet smoke box radar detection device, the intermediate frequency signal acquisition and control unit uses the STM32H7 series main control chip. The main control chip is connected to an ADS54J60 ADC module and an AD9164 DAC module. The main control chip is also connected to an AD9528 clock chip and a TPS62130 DC-DC step-down chip.

[0008] In the aforementioned X-band MIMO system sheet smoke box radar detection device, the broadband linear frequency modulation signal generation unit includes a DDS digital frequency synthesizer, and the DDS chip is connected to an up-conversion link.

[0009] In the aforementioned X-band MIMO system sheet smoke box radar detection device, the upconversion link includes a PLL phase-locked loop connection, and the PLL is connected to the power amplifier through a filter.

[0010] In the aforementioned X-band MIMO system sheet smoke box radar detection device, the DDS digital frequency synthesizer is model AD9914, and the PLL phase-locked loop is model ADF5355.

[0011] In the aforementioned X-band MIMO system sheet smoke box radar detection device, the transceiver antenna array unit includes a transmit switch array, which is connected to a transmit antenna array. The transmit antenna array is equipped with a receive antenna array, which is connected to a receive switch array.

[0012] In the aforementioned X-band MIMO system sheet smoke box radar detection device, the transmitting switch array uses the QPC6014 RF switch chip, and the receiving switch array uses the HMC1114 multiplexing switch chip.

[0013] In the aforementioned X-band MIMO system sheet smoke box radar detection device, the mixing receiver unit includes a radio frequency amplifier, which is connected to a down-conversion link.

[0014] In the aforementioned X-band MIMO system sheet smoke box radar detection device, the downconversion link includes a mixer, and the mixer is connected to an intermediate frequency filter.

[0015] In the aforementioned X-band MIMO system sheet smoke box radar detection device, the mixer model HMC220B is selected.

[0016] Compared with existing technologies, the advantages of this invention are as follows: it uses a broadband linear frequency modulated signal as the detection signal, which can not only obtain broadband echo amplitude information, but also include phase information, thereby estimating moisture content and significantly improving measurement accuracy and resolution; it utilizes antenna array technology to achieve rapid electrical scanning of the antenna array direction, thereby significantly improving the efficiency of moisture content detection and impurity detection, and enhancing product reliability; it is suitable for high-speed measurement of tobacco box cross-sections without affecting the normal working process of tobacco leaf re-drying. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of this utility model;

[0018] Figure 2 This is a schematic diagram of the broadband linear frequency modulation signal generation unit of this utility model;

[0019] Figure 3 This is a schematic diagram of the transceiver antenna array unit of this utility model;

[0020] In the figure, there are: intermediate frequency signal acquisition and control unit 1, broadband linear frequency modulation signal generation unit 2, DDS digital frequency synthesizer 21, PLL phase-locked loop 22, filter 23, power amplifier 24, transceiver antenna array unit 3, transmit switch array 31, transmit antenna array 32, receive antenna array 33, receive switch array 34, and mixer receiver unit 4. Detailed Implementation

[0021] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0022] like Figure 1-3 As shown, an X-band MIMO system sheet smoke box radar detection device includes an intermediate frequency (IF) signal acquisition and control unit 1. The IF signal acquisition and control unit 1 is connected to a broadband linear frequency modulation (LFM) signal generation unit 2. The IF signal acquisition and control unit 1 controls the broadband LFM signal generation unit 2 to generate two X-band broadband LFM signals, which serve as reference signals for the transmitted and received signals, respectively. The broadband LFM signal generation unit 2 is connected to a transceiver antenna array unit 3. Both the transmitted and received signals are switched at high speed by a switch within the transceiver antenna array unit 3 to complete the transmission signal's radiation and echo signal reception from the target. The transceiver antenna array unit 3 is connected to a mixing and receiving unit 4. The received echo signal undergoes down-conversion processing by the mixing and receiving unit 4. Finally, the IF signal acquisition and control unit 1 performs digital down-conversion of the received IF signal, achieving baseband acquisition of the target echo signal.

[0023] Specifically, the intermediate frequency signal acquisition and control unit 1 uses the STM32H7 series main control chip. The main control chip is connected to an ADS54J60 ADC module and an AD9164 DAC module. The main control chip is also connected to an AD9528 clock chip and a TPS62130 DC-DC step-down chip.

[0024] Specifically, the broadband linear frequency modulation signal generation unit 2 includes a DDS digital frequency synthesizer 21, with the DDS chip connected to an upconversion link. The DDS digital frequency synthesizer 21 has two components that are synchronized by a synchronization signal, and it generates two relatively low-frequency reference signals, which are respectively input to the upconversion link.

[0025] Furthermore, the upconversion link includes a PLL (Phase-Locked Loop) 22, which is connected to a power amplifier 24 via a filter 23. The PLL 22 receives a reference signal and is configured as a fixed integer multiple. Based on a lower frequency reference signal, it is phase-locked to the X-band, completing the frequency shift. The X-band broadband linear frequency modulated signal output from the PLL 22 is filtered by the filter 23 to improve the signal-to-noise ratio of the detection signal. Then, the power amplifier 24 amplifies the two signals to power suitable for detection and power required for the receiving reference local oscillator, respectively.

[0026] Furthermore, the DDS digital frequency synthesizer 21 is model AD9914, and the PLL phase-locked loop 22 is model ADF5355.

[0027] In addition, the transceiver antenna array unit 3 includes a transmit switch array 31, which is connected to a transmit antenna array 32. The transmit antenna array 32 is equipped with a receive antenna array 33, which is connected to a receive switch array 34. The receive antenna array 33 and the receive antenna array 34 are fixed at fixed positions in three-dimensional space, which are the spatial sampling positions. First, the transmitted signal is switched to a fixed channel through the transmit switch array 31. At this time, the signal is radiated to the target at a fixed transmission position in space. At the same time, the receive switch array 34 sequentially opens all the receive channels to collect echo signals from all the receive positions in all the space. This process is repeated in a loop to complete the switching of all the transmit channels and all the receive channels, thereby realizing the detection of the target from different directions.

[0028] Meanwhile, the transmit switch array 31 uses the QPC6014 RF switch chip, and the receive switch array 34 uses the HMC1114 multiplexing switch chip.

[0029] As can be seen, the mixer receiving unit 4 down-converts the echo signal to an intermediate frequency, including an RF amplifier, which is connected to a down-conversion link.

[0030] Clearly, the downconversion link includes a mixer connected to an intermediate frequency (IF) filter. The mixer typically includes a local oscillator and a filter. The digital downconversion section is implemented in an FPGA or DSP, utilizing IP cores or dedicated algorithms to process the IF signal and convert it to baseband.

[0031] Preferably, the mixer is an HMC220B model, which is connected to an ADF5355 PLL synthesizer, and the center frequency of the filter used is 57MHz.

[0032] In summary, the principle of this embodiment is as follows: the intermediate frequency signal acquisition and control unit 1 uses control signals to generate two broadband linear frequency modulation signals by the broadband linear frequency modulation signal generation unit 2. One signal is used as a detection signal and the other is used as a local oscillator signal. The detection signal completes the detection of a section of the target by rapidly switching between different transmit and receive channels of the transmit and receive antenna array unit 3. The echo signal of the target and the local oscillator reference signal are mixed by the mixing and receiving unit 4 to obtain the intermediate frequency echo signal of the target. Then, the baseband acquisition of the target echo signal is completed by digital down-conversion, thereby completing the correlation detection of the target.

[0033] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

[0034] Although this document frequently uses terms such as intermediate frequency signal acquisition and control unit 1, broadband linear frequency modulation signal generation unit 2, DDS digital frequency synthesizer 21, PLL phase-locked loop 22, filter 23, power amplifier 24, transceiver antenna array unit 3, transmit switch array 31, transmit antenna array 32, receive antenna array 33, receive switch array 34, and mixer receiver unit 4, the possibility of using other terms is not excluded. These terms are used merely for the convenience of describing and explaining the essence of this utility model; interpreting them as any additional limitation would contradict the spirit of this utility model.

Claims

1. A radar detection device for X-band MIMO system sheet smoke boxes, characterized in that, It includes an intermediate frequency signal acquisition and control unit (1), which is connected to a broadband linear frequency modulation signal generation unit (2), which is connected to a transceiver antenna array unit (3), and the transceiver antenna array unit (3) is connected to a mixer receiving unit (4).

2. The X-band MIMO system sheet smoke box radar detection device according to claim 1, characterized in that, The intermediate frequency signal acquisition and control unit (1) uses the STM32H7 series main control chip. The main control chip is connected to an ADS54J60 ADC module and an AD9164 DAC module. The main control chip is also connected to an AD9528 clock chip and a TPS62130 DC-DC step-down chip.

3. The X-band MIMO system sheet smoke box radar detection device according to claim 1, characterized in that, The broadband linear frequency modulation signal generation unit (2) includes a DDS digital frequency synthesizer (21), which is connected to an upconversion link.

4. The X-band MIMO system sheet smoke box radar detection device according to claim 3, characterized in that, The upconversion link includes a PLL phase-locked loop (22) connection, and the PLL phase-locked loop (22) is connected to the power amplifier (24) through a filter (23).

5. The X-band MIMO system sheet smoke box radar detection device according to claim 4, characterized in that, The DDS digital frequency synthesizer (21) is model AD9914, and the PLL phase-locked loop (22) is model ADF5355.

6. The X-band MIMO system sheet smoke box radar detection device according to claim 1, characterized in that, The transceiver antenna array unit (3) includes a transmit switch array (31), which is connected to a transmit antenna array (32). The transmit antenna array (32) is equipped with a receive antenna array (33), which is connected to a receive switch array (34).

7. The X-band MIMO system sheet smoke box radar detection device according to claim 6, characterized in that, The transmit switch array (31) uses the QPC6014 RF switch chip, and the receive switch array (34) uses the HMC1114 multiplexing switch chip.

8. The X-band MIMO system sheet smoke box radar detection device according to claim 1, characterized in that, The mixing receiver unit (4) includes a radio frequency amplifier, which is connected to a downconversion link.

9. The X-band MIMO system sheet smoke box radar detection device according to claim 8, characterized in that, The downconversion link includes a mixer, which is connected to an intermediate frequency filter.

10. The X-band MIMO system sheet smoke box radar detection device according to claim 9, characterized in that, The mixer used is model HMC220B.

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