L-band foundation tree penetration warning radar based on FMCW (frequency modulated continuous wave) system

Abstract

The utility model relates to an FMCW (frequency modulated continuous wave)-system-based L-wave-band ground-based tree penetration warning radar, which comprises a radio-frequency signal transceiving system, a radar data processing system and an antenna, and is characterized in that the radio-frequency signal transceiving system comprises an L-wave-band transmitting link, a first L-wave-band receiving link and a second L-wave-band receiving link; the antenna comprises an L-band transmitting antenna, a first L-band receiving antenna and a second L-band receiving antenna. According to the embodiment of the invention, trees, leaves and other natural camouflage objects can be better penetrated, hidden objects can be identified, and the accuracy and the stability of signals are improved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to radar technical field, concretely relates to a kind of L wave band ground-based tree penetration warning radar based on FMCW system. BACKGROUND

[0002] Warning radar is widely used in military, mainly for monitoring enemy action, tracking moving targets, monitoring camouflage military equipment etc.But in jungle and mountain warfare, enemy usually relies on vegetation and natural environment to carry out covert action, and the main monitoring means for hidden targets under forest at present is to use P wave band airborne SAR imaging radar, and conventional ground-based warning radar often cannot effectively detect enemy targets.

[0003] Therefore, the existing radar has difficulty in detecting targets in complex combat environment such as jungle. UTILITY MODEL CONTENT

[0004] In order to solve the above problems existing in the prior art, the utility model provides an L wave band ground-based tree penetration warning radar based on FMCW system. The technical problem to be solved by the utility model is solved by the following technical scheme:

[0005] The utility model embodiment provides an L wave band ground-based tree penetration warning radar based on FMCW system, comprising: radio frequency signal transceiver system, radar data processing system and antenna, the radio frequency signal transceiver system includes L wave band transmitting link, first L wave band receiving link and second L wave band receiving link, the antenna includes: L wave band transmitting antenna, first L wave band receiving antenna and second L wave band receiving antenna, wherein,

[0006] The first power output end of the L wave band transmitting link is connected with the power input end of the first L wave band receiving link, the second power output end of the L wave band transmitting link is connected with the power input end of the second L wave band receiving link, and the signal output end of the L wave band transmitting link is connected with the L wave band transmitting antenna;

[0007] The signal receiving end of the first L wave band receiving link is connected with the first L wave band receiving antenna, and the signal receiving end of the second L wave band receiving link is connected with the second L wave band receiving antenna;

[0008] The analog signal transmitting end of the first L wave band receiving link and the analog signal transmitting end of the second L wave band receiving link are connected with the radar data processing system.

[0009] In an embodiment of the utility model, the L wave band transmitting link includes: constant temperature crystal oscillator, frequency synthesizer, loop filter, voltage controlled oscillator, first signal power amplifier, first power divider, second signal power amplifier, first digital control attenuator, third signal power amplifier, radio frequency signal output port and second power divider, wherein,

[0010] The constant temperature crystal oscillator, the frequency synthesizer, the loop filter, the voltage controlled oscillator, the first signal power amplifier, the first power divider are sequentially connected, and the reference frequency output end of the frequency synthesizer is connected with the reference frequency input end of the voltage controlled oscillator;

[0011] The first power output end of the first power divider is connected with the input end of the second signal power amplifier, and the second power output end is connected with the input end of the second power divider;

[0012] The second signal power amplifier, the first digital control attenuator, the third signal power amplifier, the radio frequency signal output port are sequentially connected, and the radio frequency signal output port is connected with the L wave band transmitting antenna;

[0013] The first power output end of the second power divider is connected with the power input end of the first L wave band receiving link, and the second power output end is connected with the power input end of the second L wave band receiving link;

[0014] The first signal power amplifier, the second signal power amplifier adopt L wave band power amplifier;The first power divider, second power divider adopt wilkinson power divider.

[0015] In an embodiment of the utility model, the first L wave band receiving link and second L wave band receiving link are same in structure.

[0016] In an embodiment of the utility model, the first L wave band receiving link and second L wave band receiving link all include: radio frequency signal receiving port, first band pass filter, first stage low noise operational amplifier, second digital control attenuator, second stage low noise operational amplifier, second band pass filter, single-ended to differential balun, mixer, high pass filter, automatic gain control circuit and analog signal transmitting port, wherein,

[0017] The radio frequency signal receiving port, the first band pass filter, the first stage low noise operational amplifier, the second digital control attenuator, the second stage low noise operational amplifier, second band pass filter, the single-ended to differential balun, the mixer, the high pass filter, the automatic gain control circuit and the analog signal transmitting port are sequentially connected;

[0018] The mixer in the first L-band receiving link is connected with the first power output end of the L-band transmitting link; and the mixer in the second L-band receiving link is connected with the second power output end of the L-band transmitting link.

[0019] The first-stage low-noise operational amplifier and the second-stage low-noise operational amplifier are L-band operational amplifiers; and the mixer is an L-band mixer.

[0020] In an embodiment of the utility model, the output end of the mixer is an IQ quadrature output port.

[0021] The analog signal transmitting port is a quadrature differential output port.

[0022] In an embodiment of the utility model, the radar data processing system comprises a fully differential operational amplifier, an analog-to-digital converter, a data processing unit and a transmission interface, wherein,

[0023] The input end of the operational amplifier is connected with the analog signal transmitting end of the first L-band receiving link and the analog signal transmitting end of the second L-band receiving link; and the fully differential operational amplifier, the analog-to-digital converter, the data processing unit and the transmission interface are connected in sequence.

[0024] The transmission interface is used for connecting a host computer.

[0025] In an embodiment of the utility model, the analog-to-digital converter comprises a 16-bit double-channel differential analog-to-digital converter.

[0026] The data processing unit comprises a cascaded data processing unit based on an STM32H7 series microcontroller.

[0027] The transmission interface comprises a 100 Mbps Ethernet transmission interface.

[0028] In an embodiment of the utility model, the antenna further comprises an isolation device, wherein,

[0029] The L-band transmitting antenna, the first L-band receiving antenna and the second L-band receiving antenna are arranged side by side and at intervals.

[0030] The isolation device is arranged between the L-band transmitting antenna and the first L-band receiving antenna.

[0031] In an embodiment of the utility model, each antenna surface array in the L-band transmitting antenna, the first L-band receiving antenna and the second L-band receiving antenna comprises a radiating patch, a first dielectric plate, a ground plate, a second dielectric plate and a reflecting plate, wherein,

[0032] The radiation patch, the first dielectric plate, the floor, the second dielectric plate and the reflection plate are stacked in sequence.

[0033] An H-shaped slot is formed on the radiation patch.

[0034] In an embodiment of the present application, the radio frequency signal transceiver system (1) further comprises a communication device using a 485 bus protocol.

[0035] Compared with the prior art, the present application has the following beneficial effects:

[0036] 1. The radar of the present application generates L-band signals through an L-band transmitting link and transmits the signals through an L-band transmitting antenna, and transmits the L-band signals received by an L-band receiving antenna through an L-band receiving link, so that the L-band radar can better penetrate trees, leaves and other natural camouflage and identify hidden objects compared with high-frequency radar; further, a radar data processing system is used to process the received data, thereby extracting target information and greatly improving the accuracy and stability of the signals.

[0037] 2. The radio frequency signal transceiver system of the present application uses one transmitting link and two receiving links, and uses one transmitting antenna and two receiving antennas, and is internally designed in a modular manner, so that each module can be independently connected to an upper computer for debugging, fault judgment can be quickly performed, maintenance is easy, replacement is convenient, and the difficulty of maintenance is greatly reduced.

[0038] 3. The present application sets an isolation device between the transmitting antenna and the receiving antenna, so that the transmitting and receiving antennas of the L-band have very high isolation, the coupling of the L-band signals is reduced, and the dynamic range of the transmitting and receiving machine link is very large, so that the problem of strong coupling of large transmitting power and saturation of the radar receiver can be overcome. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 A structure diagram of an L-band ground-based tree penetration warning radar based on an FMCW system is provided for the embodiment of the present application.

[0040] Figure 2 A composition block diagram of a radio frequency signal transceiver system is provided for the embodiment of the present application.

[0041] Figure 3 A composition block diagram of a radar data processing system is provided for the embodiment of the present application.

[0042] Figure 4 A position diagram of an antenna is provided for the embodiment of the present application.

[0043] Figures 5a-5bA structure schematic diagram of an antenna array provided by the utility model embodiment;

[0044] Figure 6 The original waveform diagram of collecting data after the FMCW radar signal transceiving module is connected with the 100m coaxial cable is provided by the utility model embodiment;

[0045] Figure 7 The structure schematic diagram of the L band ground-based tree penetration warning radar based on the FMCW system provided by the utility model embodiment; Figure 4 The frequency spectrum result diagram after the waveform is subjected to FFT. Specific implementation

[0046] The utility model will be further described in detail in combination with specific embodiments, but the implementation mode of the utility model is not limited to this.

[0047] Embodiment one

[0048] The hardware is designed for complex combat environment such as jungle, and the purpose is to provide a kind of warning radar equipment for detecting concealed moving target when applicable in jungle and mountain combat, which is easy to maintain, high reliability.

[0049] Please see Figure 1 , Figure 1 The structure schematic diagram of the L band ground-based tree penetration warning radar based on the FMCW system provided by the utility model embodiment.

[0050] The L band ground-based tree penetration warning radar based on the FMCW system includes: radio frequency signal transceiving system 1, radar data processing system 2 and antenna 3. Wherein, radio frequency signal transceiving system 1 can emit the frequency-modulated continuous wave electromagnetic radiation signal of L band via host computer configuration;Radar data processing system 2 can select different data transmission mode and pass the intermediate frequency signal generated by radio frequency front end mixing to host computer processing via host computer configuration. Antenna 3 adopts high isolation L band antenna, and it has higher isolation to electromagnetic wave at L band center frequency, can greatly reduce the coupling between radar system transceiving antenna.

[0051] Specifically, the radio frequency signal transceiving system 1 comprises an L-band transmitting link 11, a first L-band receiving link 12 and a second L-band receiving link 13, and the antenna 3 comprises an L-band transmitting antenna 31, a first L-band receiving antenna 32 and a second L-band receiving antenna 33. The first power output end of the L-band transmitting link 11 is connected with the power input end of the first L-band receiving link 12, the second power output end of the L-band transmitting link 11 is connected with the power input end of the second L-band receiving link 13, and the signal output end of the L-band transmitting link 11 is connected with the L-band transmitting antenna 31. The signal receiving end of the first L-band receiving link 12 is connected with the first L-band receiving antenna 32, and the signal receiving end of the second L-band receiving link 13 is connected with the second L-band receiving antenna 33. The analog signal transmitting end of the first L-band receiving link 12 and the analog signal transmitting end of the second L-band receiving link 13 are both connected with the radar data processing system 2.

[0052] Please refer to Figure 2 , Figure 2 The utility model provides a kind of composition block diagram of radio frequency signal transceiving system for embodiment of the utility model.

[0053] In one embodiment, the L-band transmitting link 11 is mainly composed of a local oscillator module and a radio frequency power amplifier, specifically comprising: a constant temperature crystal oscillator 101, a frequency synthesizer 102, a loop filter 103, a voltage-controlled oscillator VCO 104, a first signal power amplifier PA 105, a first power divider 106, a second signal power amplifier PA 107, a first digital attenuator ATT 108, a third signal power amplifier PA 109, a radio frequency signal output port 110 and a second power divider 111. The constant temperature crystal oscillator 101, the frequency synthesizer 102, the loop filter 103, the voltage-controlled oscillator 104, the first signal power amplifier 105 and the first power divider 106 are connected in sequence, and the reference frequency output end of the frequency synthesizer 102 is connected with the reference frequency input end of the voltage-controlled oscillator 104. The first power output end of the first power divider 106 is connected with the input end of the second signal power amplifier 107, and the second power output end is connected with the input end of the second power divider 111. The second signal power amplifier 107, the first digital attenuator 108, the third signal power amplifier 109 and the radio frequency signal output port 110 are connected in sequence, and the radio frequency signal output port 110 is connected with the L-band transmitting antenna 31. The first power output end of the second power divider 111 is connected with the power input end of the first L-band receiving link 12, and the second power output end is connected with the power input end of the second L-band receiving link 13. The first signal power amplifier 105 and the second signal power amplifier 107 are L-band power amplifiers. The first power divider 106 and the second power divider 111 are Wilkinson power dividers.

[0054] Specifically, the constant temperature crystal oscillator 101, the frequency synthesizer 102, the loop filter 103 and the voltage controlled oscillator VCO 104 constitute a complete phase-locked loop system. The frequency output by the constant temperature crystal oscillator 101 is multiplied to generate a reference frequency inside the frequency synthesizer 102 chip. The PFD (phase frequency comparator) inside the chip compares the output frequency of the voltage controlled oscillator VCO 104 with the reference frequency and sends charge and discharge signals to the CP (charge pump) according to the result. The voltage generated after charging and discharging the loop filter 103 can control the oscillation frequency of the voltage controlled oscillator VCO 104. The first signal power amplifier 105 and the first power divider 106 constitute a power division system. The divided power is used for output and output to the mixer as a local oscillator signal. The second signal power amplifier 107, the first digital control attenuator 108, the third signal power amplifier 109 and the radio frequency signal output port 110 constitute a power amplifier system, which ensures that the FMCW transmission signal has sufficient power.

[0055] In one specific embodiment, the first L-band receiving link 12 and the second L-band receiving link 13 have the same structure and each include a radio frequency signal receiving port 112, a first band-pass filter 113, a first-stage low-noise operational amplifier LNA 114, a second digital control attenuator 115, a second-stage low-noise operational amplifier LNA 116, a second band-pass filter 117, a single-ended-to-differential balun 118, a mixer 119, a high-pass filter 120, an automatic gain control circuit AGC 121 and an analog signal transmitting port 122, wherein the radio frequency signal receiving port 112, the first band-pass filter 113, the first-stage low-noise operational amplifier LNA 114, the second digital control attenuator 115, the second-stage low-noise operational amplifier LNA 116, the second band-pass filter 117, the single-ended-to-differential balun 118, the mixer 119, the high-pass filter 120, the automatic gain control circuit 121 and the analog signal transmitting port 122 are connected in sequence; the mixer 119 in the first L-band receiving link 12 is connected to the first power output end of the L-band transmitting link 11; the mixer 119 in the second L-band receiving link 13 is connected to the second power output end of the L-band transmitting link 11; the first-stage low-noise operational amplifier LNA 114 and the second-stage low-noise operational amplifier LNA 116 are L-band operational amplifiers; and the mixer 119 is an L-band mixer.

[0056] Further, the output end of the mixer 119 is an IQ quadrature output port.

[0057] Specifically, the radio frequency signal receiving port 112, the first band-pass filter 113, the first-stage low-noise operational amplifier 114, the second digital control attenuator 115, and the second-stage low-noise operational amplifier 116 constitute a front-stage gain control system of the receiving link, and can make the receiving link unsaturated by selecting appropriate gain through the host computer.

[0058] In one specific embodiment, the radio frequency signal transceiving system 1 further comprises a communication device using a 485 bus protocol.

[0059] In this embodiment, the receiving link gain of the radar radio frequency signal transceiving system is maximally 85 dB, and the output signal power of the transmitting link is adjustable between 12 dBm and 50 dBm, for example, 12 dBm, and has a very high dynamic range, which can be adjusted by the host computer.

[0060] Please refer to Figure 3 , Figure 3 A composition block diagram of a radar data processing system provided by the embodiment of the utility model.

[0061] In one specific embodiment, the radar data processing system 2 comprises a fully differential operational amplifier 201, an analog-to-digital converter 202, a data processing unit 203 and a transmission interface 204, wherein the input end of the fully differential operational amplifier 201 is connected to the analog signal transmitting end of the first L-band receiving link 12 and the analog signal transmitting end of the second L-band receiving link 13; the fully differential operational amplifier 201, the analog-to-digital converter 202, the data processing unit 203 and the transmission interface 204 are connected in sequence; and the transmission interface 204 is used to connect to the host computer.

[0062] Specifically, the fully differential operational amplifier 201 adopts a high-precision low-noise wideband fully differential operational amplifier, mainly serving as a voltage follower to play an isolating role. The analog-to-digital converter 202 comprises a 16-bit high-precision double-channel differential analog-to-digital converter, with a sampling rate of 350KSPS, which completes ADC collection of the analog IQ differential signal output by the front-end radio frequency signal transceiver module and converts it into a digital signal to be transmitted to the data processing unit 203 through an SPI interface. The data processing unit 203 comprises a cascaded data processing unit based on an STM32H7 series microcontroller, specifically comprising a front-stage processing unit, an intermediate-stage processing unit, a rear-stage processing unit and a terminal transmission-stage processing unit, each of which adopts an STM32H7 chip; the data processing unit 203 is used to perform a series of processing on the received signal, including distance compression, filtering, two-dimensional FFT, clutter suppression, coherent accumulation, moving target extraction, CFAR detection processing and the like. The transmission interface 204 comprises a hundred-megabit Ethernet transmission interface, which is used to transmit the processed data to the host computer for display, so as to ensure good interaction between the radar operator and the radar.

[0063] Please refer to Figure 4 , Figure 4 The utility model provides a position schematic view of antenna.

[0064] The antenna 3 comprises an L-band transmitting antenna 31, a first L-band receiving antenna 32, a second L-band receiving antenna 33 and an isolating device 34. The L-band transmitting antenna 31, the first L-band receiving antenna 32 and the second L-band receiving antenna 33 are arranged side by side and spaced apart; the isolating device 34 adopts a high-isolation transceiving isolating device, which is arranged between the L-band transmitting antenna 31 and the first L-band receiving antenna 32, can overcome the defect that the L-band coupling is strong, and greatly reduces the coupling between the transceiving antennas of the radar system.

[0065] Further, the L-band transmitting antenna 31, the first L-band receiving antenna 32 and the second L-band receiving antenna 33 are all composed of array faces, and the array faces are connected through a power dividing network.

[0066] Please refer to Figures 5a-5b , Figures 5a-5bThe utility model provides a structure schematic drawing of antenna face array.

[0067] Each antenna face array includes radiating patch 301, first dielectric plate 302, ground plate 303, second dielectric plate 304 and reflecting plate 305, wherein, radiating patch 301, first dielectric plate 302, ground plate 303, second dielectric plate 304 and reflecting plate 305 are stacked in turn, H type slit is set up on radiating patch 301.

[0068] Specifically, the dielectric plate material used by the first dielectric plate 302 and the second dielectric plate 304 is FR4, the dielectric constant is 4.4, the overall profile height of the antenna is 38mm, the second dielectric plate 304 is connected to the microstrip line, and the H type slit is set up to couple energy to the first dielectric plate 302. The 2*2 face array inside the antenna is added to the power division network, which can realize a gain of 12.9dB, an E-plane beam width of 30°, an H-plane beam width of 45°, and a bandwidth of 100MHz.

[0069] Please refer to Figure 6 , Figure 6 The utility model provides the original waveform graph of data collection after FMCW radar signal transceiving module is connected 100m coaxial cable provided by the utility model embodiment. 100m coaxial cable is used to simulate physical space path to test the performance of FMCW signal transceiving module, and the test condition is set as follows: radar carrier frequency 1121MHz, frequency modulation time T chirp =10ms, frequency modulation bandwidth B=75MHz. Only the test result of A road is shown in the drawing, and line A I in the drawing represents the voltage waveform collected by A road I channel, A Q in the drawing represents the voltage waveform collected by A road Q channel, the vertical axis is amplitude, the horizontal axis is sampling point number, and it is observed that the waveform is a standard sine wave, which meets the expectation.

[0070] Please refer to Figure 7 , Figure 7 The utility model provides the spectrum result graph after the waveform of Figure 4 is carried out FFT (fast fourier transform). Figure 7 The spectrum after the data in Figure 4 is carried out FFT, and the peak value of the spectrum appears at 49.5m, which is 0.5m different from 50m, meeting the expectation.

[0071] The radar of the embodiment generates L-band signals through an L-band transmitting link and transmits through an L-band transmitting antenna, and transmits the L-band signals received by the L-band receiving antenna through an L-band receiving link, compared with the C and X-band radars of high frequency bands, the L-band radar can better penetrate trees, leaves and other natural disguises, and identify hidden objects; further, a radar data processing system is used to process the received data, so as to complete extraction of target information, greatly improving the accuracy and stability of the signals; in addition, the continuous wave signal of the FMCW radar can be averaged for a longer time compared with the pulse signal, so as to improve the signal-to-noise ratio and improve the accuracy of detecting targets in complex environments. The tree-penetrating radar of the embodiment can obtain significant tactical advantages in military tasks, especially in reconnaissance and surveillance in forests, mountains and other complex terrains.

[0072] The radio frequency signal transceiving system of the embodiment adopts one transmitting link and two receiving links, the antenna adopts one transmitting antenna and two receiving antennas, and the internal part adopts modular design, each module can be independently connected to the host computer for debugging, fault judgment can be quickly performed, maintenance is easy, replacement is convenient, and the difficulty of maintenance is greatly reduced.

[0073] The embodiment sets an isolation device between the transmitting antenna and the receiving antenna, so that the transmitting and receiving antennas of the L-band have very high isolation, the coupling of the L-band signals is reduced, and the dynamic range of the transmitting and receiving machine link is very large, so that the problem that the radar receiver is saturated due to the strong coupling of the large transmitting power can be overcome.

[0074] The above is a further detailed description of the utility model in combination with the specific preferred embodiment, and the specific implementation of the utility model cannot be limited to these descriptions. For ordinary skilled persons in the technical field to which the utility model belongs, without departing from the concept of the utility model, a number of simple deductions or substitutions can be made, and all of them should be regarded as belonging to the protection range of the utility model.

Claims

1. A L-band ground-based tree penetration warning radar based on FMCW system, characterized in that, The application relates to a radio frequency signal transceiving system (1), a radar data processing system (2) and an antenna (3), wherein the radio frequency signal transceiving system (1) comprises an L-band transmitting chain (11), a first L-band receiving chain (12) and a second L-band receiving chain (13), and the antenna (3) comprises an L-band transmitting antenna (31), a first L-band receiving antenna (32) and a second L-band receiving antenna (33), wherein, a first power output end of the L-band transmitting chain (11) is connected with a power input end of the first L-band receiving chain (12), a second power output end of the L-band transmitting chain (11) is connected with a power input end of the second L-band receiving chain (13), and a signal output end of the L-band transmitting chain (11) is connected with the L-band transmitting antenna (31); a signal receiving end of the first L-band receiving chain (12) is connected with the first L-band receiving antenna (32), and a signal receiving end of the second L-band receiving chain (13) is connected with the second L-band receiving antenna (33); an analog signal transmitting end of the first L-band receiving chain (12) and an analog signal transmitting end of the second L-band receiving chain (13) are connected with the radar data processing system (2). the L-band transmitting chain (11) comprises a constant-temperature crystal oscillator (101), a frequency synthesizer (102), a loop filter (103), a voltage-controlled oscillator (104), a first signal power amplifier (105), a first power divider (106), a second signal power amplifier (107), a first digital control attenuator (108), a third signal power amplifier (109), a radio frequency signal output port (110) and a second power divider (111), wherein, 2. The L-band ground-based tree penetration warning radar based on FMCW regime according to claim 1, characterized in that, the constant-temperature crystal oscillator (101), the frequency synthesizer (102), the loop filter (103), the voltage-controlled oscillator (104), the first signal power amplifier (105) and the first power divider (106) are sequentially connected, and a reference frequency output end of the frequency synthesizer (102) is connected with a reference frequency input end of the voltage-controlled oscillator (104); a first power output end of the first power divider (106) is connected with an input end of the second signal power amplifier (107), and a second power output end is connected with an input end of the second power divider (111); the second signal power amplifier (107), the first digital control attenuator (108), the third signal power amplifier (109) and the radio frequency signal output port (110) are sequentially connected, and the radio frequency signal output port (110) is connected with the L-band transmitting antenna (31); a first power output end of the second power divider (111) is connected with a power input end of the first L-band receiving chain (12), and a second power output end is connected with a power input end of the second L-band receiving chain (13). ​ The first signal power amplifier (105) and the second signal power amplifier (107) adopt L-band power amplifiers; the first power divider (106) and the second power divider (111) adopt Wilkinson power dividers. 3.The L-band ground-based tree penetration warning radar based on FMCW regime according to claim 1, wherein, The first L-band receiving link (12) and the second L-band receiving link (13) have the same structure. 4.The L-band ground-based tree penetration warning radar based on FMCW regime according to claim 1, wherein, The first L-band receiving link (12) and the second L-band receiving link (13) each comprise a radio frequency signal receiving port (112), a first band-pass filter (113), a first-stage low-noise operational amplifier (114), a second digital control attenuator (115), a second-stage low-noise operational amplifier (116), a second band-pass filter (117), a single-ended-to-differential balun (118), a mixer (119), a high-pass filter (120), an automatic gain control circuit (121), and an analog signal transmitting port (122), wherein, The radio frequency signal receiving port (112), the first band-pass filter (113), the first-stage low-noise operational amplifier (114), the second digital control attenuator (115), the second-stage low-noise operational amplifier (116), the second band-pass filter (117), the single-ended-to-differential balun (118), the mixer (119), the high-pass filter (120), the automatic gain control circuit (121), and the analog signal transmitting port (122) are connected in sequence; The mixer (119) in the first L-band receiving link (12) is connected to the first power output end of the L-band transmitting link (11); the mixer (119) in the second L-band receiving link (13) is connected to the second power output end of the L-band transmitting link (11); The first-stage low-noise operational amplifier (114) and the second-stage low-noise operational amplifier (116) adopt L-band operational amplifiers; the mixer (119) adopts an L-band mixer.

5. The L-band ground-based tree penetration warning radar based on FMCW regime according to claim 4, characterized in that, The output end of the mixer (119) is an IQ quadrature output port; The analog signal transmitting port (122) is a quadrature differential output port.

6. The L-band ground-based tree penetration alert radar based on FMCW regime according to claim 1, characterized in that, The radar data processing system (2) comprises a fully differential operational amplifier (201), an analog-to-digital converter (202), a data processing unit (203), and a transmission interface (204), wherein, The input end of the fully differential operational amplifier (201) is connected to the analog signal transmitting end of the first L-band receiving link (12) and the analog signal transmitting end of the second L-band receiving link (13); the fully differential operational amplifier (201), the analog-to-digital converter (202), the data processing unit (203), and the transmission interface (204) are connected in sequence; The transmission interface (204) is used to connect a host computer.

7. The L-band ground-based tree penetration alert radar based on FMCW regime according to claim 6, characterized in that, The analog-to-digital converter (202) comprises a 16-bit double-channel differential analog-to-digital converter; The data processing unit (203) comprises a cascaded data processing unit based on an STM32H7 series microcontroller; The transmission interface (204) comprises a 100 Mbps Ethernet transmission interface. 8.The L-band ground-based tree penetration warning radar based on FMCW regime according to claim 1, wherein, The antenna (3) further comprises an isolation device (34), wherein The L-band transmitting antenna (31), the first L-band receiving antenna (32) and the second L-band receiving antenna (33) are arranged side by side and spaced apart. The isolation device (34) is arranged between the L-band transmitting antenna (31) and the first L-band receiving antenna (32). 9.The L-band ground-based tree penetration warning radar based on FMCW regime according to claim 1, wherein, Each of the L-band transmitting antenna (31), the first L-band receiving antenna (32) and the second L-band receiving antenna (33) comprises a radiating patch (301), a first dielectric plate (302), a ground plate (303), a second dielectric plate (304) and a reflecting plate (305), wherein The radiating patch (301), the first dielectric plate (302), the ground plate (303), the second dielectric plate (304) and the reflecting plate (305) are stacked in sequence. An H-shaped slot is formed on the radiating patch (301).

10. The L-band ground-based tree penetration alert radar based on FMCW regime according to claim 1, characterized in that, The radio frequency signal transceiver system (1) further comprises a communication device using a 485 bus protocol.

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