A method, device and equipment for dual-channel stepped-frequency ground penetrating radar radio frequency

Abstract

The present application relates to the field of microwave electronic technology, and in particular to a method, device, and apparatus for dual-channel stepped-frequency ground-penetrating radar radio frequency, including: sending register instructions to a frequency synthesizer via an SPI serial port to obtain a sinusoidal wave auxiliary excitation signal generated by the frequency synthesizer, using the sinusoidal wave auxiliary excitation signal to obtain a local oscillator signal through power distribution; using the local oscillator signal and a pre-obtained echo radio frequency signal to perform AD on the obtained intermediate frequency signal through mixing processing, performing signal processing on the radar target signal, and obtaining radar detection imaging results. The present application helps to effectively distinguish between similar patterns of real targets and false targets such as iron wire, shrapnel, metal pipes, cans, etc. on radar maps, image the real target, improve the detection rate, and reduce the false alarm rate.

Description

Technical Field

[0001] The present application relates to the field of microwave electronic technology, and in particular to a method, device and equipment for dual-channel stepped-frequency ground penetrating radar radio frequency. Background Art

[0002] In the existing technology, single-channel pulse ground penetrating radar or stepped-frequency ground penetrating radar technology is mainly used to identify mine targets and detect and image shallowly buried unexploded ordnance. However, single-channel radar can only achieve two-dimensional detection of underground targets and cannot effectively distinguish between real targets and false targets such as wire, shrapnel, metal pipes, cans and bottles on the radar map. Summary of the Invention

[0003] In order to at least to some extent overcome the problem in the related art that it is impossible to effectively distinguish between real targets and similar patterns of false targets such as iron wire, shrapnel, metal pipes, cans and bottles on radar patterns, the present application provides a method, device and equipment for dual-channel stepped-frequency ground penetrating radar radio frequency.

[0004] The scheme of this application is as follows:

[0005] In one aspect, the present application provides a method for dual-channel stepped-frequency ground penetrating radar radio frequency, the method comprising:

[0006] Sending register instructions to the frequency synthesizer through the SPI serial port to obtain an excitation signal generated by the frequency synthesizer, wherein the excitation signal includes: a sinusoidal wave excitation signal and a sinusoidal wave auxiliary excitation signal;

[0007] Utilizing the sinusoidal wave excitation signal to transmit a radio frequency signal, thereby obtaining a radio frequency transmission signal;

[0008] receiving the radio frequency transmission signal to obtain an echo radio frequency signal;

[0009] Utilizing the sine wave auxiliary excitation signal, a local oscillation signal is obtained through power distribution;

[0010] The radar detection imaging result is obtained by mixing the local oscillator signal and the echo radio frequency signal.

[0011] Furthermore, the step of utilizing the sinusoidal wave excitation signal to obtain a radio frequency transmission signal through radio frequency transmission includes:

[0012] Based on the sinusoidal wave excitation signal, it is filtered in turn through the first switch filter network, digital up-conversion is achieved through the orthogonal modulator, filtering is performed through the second switch filter network, and full-band filtering is performed through the full-band low-pass filter and the digital attenuator to obtain the radio frequency transmission signal.

[0013] Furthermore, the obtaining of radar detection imaging results by mixing the local oscillator signal and the pre-obtained echo radio frequency signal includes:

[0014] The local oscillator signal is mixed with the pre-obtained echo radio frequency signal to generate an intermediate frequency signal, and the local oscillator signal is adjusted by an orthogonal modulator to obtain a radar detection imaging result.

[0015] In a second aspect, a dual-channel stepped-frequency ground penetrating radar radio frequency device is provided, the device comprising:

[0016] The frequency synthesis module is used to send register instructions to the frequency synthesizer through the SPI serial port to obtain the excitation signal generated by the frequency synthesizer, wherein the excitation signal includes: a sinusoidal wave excitation signal and a sinusoidal wave auxiliary excitation signal;

[0017] A frequency transmitting module, configured to utilize the sinusoidal wave excitation signal to obtain a radio frequency transmitting signal through radio frequency transmission;

[0018] An echo receiving module is used to receive the radio frequency transmission signal and obtain an echo radio frequency signal;

[0019] Used to utilize the sine wave auxiliary excitation signal to obtain a local oscillator signal through power distribution;

[0020] The local oscillator signal and the echo radio frequency signal are mixed to obtain a radar detection imaging result.

[0021] Furthermore, the frequency transmission module includes:

[0022] Based on the sinusoidal wave excitation signal, it is filtered in turn through the first switch filter network, digital up-conversion is achieved through the orthogonal modulator, filtering is performed through the second switch filter network, and full-band filtering is performed through the full-band low-pass filter and the digital attenuator to obtain the radio frequency transmission signal.

[0023] Furthermore, the echo receiving module includes: a first echo receiving channel, a second echo receiving channel, a low noise amplifier, a third switch filter network, a fourth switch filter network and an orthogonal modulator;

[0024] The echo radio frequency signal includes: a first echo radio frequency signal and a second echo radio frequency signal;

[0025] The first echo radio frequency signal is received and processed through a first echo receiving channel to obtain a first intermediate frequency signal for output;

[0026] The second echo radio frequency signal is received and processed through a second echo receiving channel to obtain a second intermediate frequency signal for output;

[0027] The first echo radio frequency signal is received and processed through a first echo receiving channel to obtain a first intermediate frequency signal for output, including:

[0028] utilizing the first echo radio frequency signal to perform low noise amplification through a low noise amplifier, and then performing filtering processing through a third switch filter network;

[0029] Based on the processing result, mixing with the local oscillator signal is performed to generate an intermediate frequency signal;

[0030] Adopting an orthogonal modulator to adjust the local oscillator signal;

[0031] The second echo radio frequency signal is received and processed through a second echo receiving channel to obtain a second intermediate frequency signal for output, including:

[0032] utilizing the second echo radio frequency signal, performing low noise amplification through a low noise amplifier, and then performing filtering processing through a fourth switch filter network;

[0033] Based on the result of the processing, mixing is performed with a pre-obtained local oscillator signal to generate a second intermediate frequency signal;

[0034] A radar detection imaging result is obtained based on the first intermediate frequency signal and the second intermediate frequency signal.

[0035] Furthermore, the echo receiving module further includes:

[0036] The first echo receiving channel and the second echo receiving channel are channels with the same function, structure and composition.

[0037] In a third aspect, the present application provides a dual-channel stepped-frequency ground penetrating radar radio frequency device, the device comprising:

[0038] At least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform any of the methods described above.

[0039] The technical solution provided by this application may have the following beneficial effects:

[0040] The present application sends register instructions to a frequency synthesizer via an SPI serial port to obtain an excitation signal generated by the frequency synthesizer, wherein the excitation signal includes: a sinusoidal excitation signal and a sinusoidal auxiliary excitation signal; utilizes the sinusoidal excitation signal to transmit an RF signal through RF transmission to obtain an RF transmission signal; receives the RF transmission signal to obtain an echo RF signal; utilizes the sinusoidal auxiliary excitation signal to obtain a local oscillator signal through power distribution; utilizes the local oscillator signal and the echo RF signal to obtain a radar detection imaging result through frequency mixing processing. The present application helps to effectively distinguish between real targets and similar patterns of false targets such as iron wire, shrapnel, metal pipes, cans, etc. on radar maps, image real targets, improve detection rates, and reduce false alarm rates.

[0041] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0043] Figure 1 This is a flow chart of a method for dual-channel stepped-frequency ground penetrating radar radio frequency provided by one embodiment of the present application;

[0044] Figure 2 This is a principle block diagram of a dual-channel stepped-frequency ground-penetrating radar radio frequency module provided by one embodiment of the present application;

[0045] Figure 3 This is a circuit diagram of a frequency synthesizer provided by one embodiment of the present application;

[0046] Figure 4 This is a radio frequency transmission module circuit provided by an embodiment of the present application Figure 1 ;

[0047] Figure 5 This is a radio frequency transmission module circuit provided by an embodiment of the present application Figure 2 ;

[0048] Figure 6 This is a radio frequency transmission module circuit provided by an embodiment of the present application Figure 3 ;

[0049] Figure 7 An echo receiving module circuit provided by an embodiment of the present application Figure 1 ;

[0050] Figure 8 An echo receiving module circuit provided by an embodiment of the present application Figure 2 ;

[0051] Figure 9 An echo receiving module circuit provided by an embodiment of the present application Figure 3 ;

[0052] Figure 10 This is a timing diagram of the first-stage switch control of radio frequency transmission provided by one embodiment of the present application;

[0053] Figure 11 This is a timing diagram of the second-stage switch control of radio frequency transmission provided by one embodiment of the present application;

[0054] Figure 12 This is a structural diagram of a dual-channel stepped-frequency ground-penetrating radar radio frequency device provided by one embodiment of the present application;

[0055] Figure 13 This is a diagram showing the composition of a dual-channel stepped-frequency ground-penetrating radar radio frequency device provided by one embodiment of the present application. DETAILED DESCRIPTION

[0056] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

[0057] Example 1

[0058] See also Figure 1 , Figure 1 This is a flow chart of a method for dual-channel stepped-frequency ground penetrating radar radio frequency provided by one embodiment of the present application, the method comprising:

[0059] S1 sends a register instruction to the frequency synthesizer via the SPI serial port to obtain an excitation signal generated by the frequency synthesizer, the excitation signal includes: a sinusoidal excitation signal and a sine wave auxiliary excitation signal;

[0060] S2. Using the sinusoidal wave excitation signal, a radio frequency transmission signal is obtained by radio frequency transmission;

[0061] S3 receives the radio frequency transmission signal to obtain an echo radio frequency signal;

[0062] S4. Using the sine wave auxiliary excitation signal, the local oscillator signal is obtained by power distribution;

[0063] S5 utilizes the local oscillator signal and the echo radio frequency signal to obtain a radar detection imaging result through frequency mixing processing.

[0064] In one embodiment, Figure 2 As shown in the figure, LO is the local oscillator signal, also known as the local oscillator signal; I is the in-phase signal component in vector modulation; Q is the quadrature signal component in vector modulation. RF is a modulated electromagnetic wave with a specific transmission frequency. Typically, RF is a general term for electromagnetic waves with an oscillation frequency between 3 kHz and 300 GHz, and is widely used in radar and wireless communications. IF is an intermediate frequency signal, which is a signal obtained by converting the RF signal.

[0065] In practice, the RF board generates a periodic sequence of 260 stepped-frequency sine continuous waves. This is generated by the MAX2870 wideband frequency synthesizer with an integrated VCO. Two channels are provided: one channel is modulated, filtered, and switched before being transmitted as the RF signal. The other channel, connected to a power splitter, is fed to two receive channels as the mixer's local oscillator signal, which is then mixed with the echoed RF signal to generate an intermediate frequency (IF) signal. The transmit channel uses an IQ quadrature modulator to modulate the RF LO signal at a 6MHz frequency.

[0066] Regarding step S1, in one embodiment, the register instruction is sent to the frequency synthesizer via the SPI serial port to obtain an excitation signal generated by the frequency synthesizer, wherein the excitation signal includes: a sinusoidal wave excitation signal and a sinusoidal wave auxiliary excitation signal, including:

[0067] The host computer FPGA sends register instructions to the frequency synthesizer MAX2870 through the SPI serial port, causing the latter to generate a 400MHz to 3000MHz sinusoidal excitation signal RFOUTB, which is sent to the RF transmitter module to generate the RF transmission signal. The MAX2870 also generates an auxiliary sinusoidal excitation signal RFOUTA at the same frequency. After power distribution, the auxiliary excitation signal is divided into two excitation signals, RFOUTA1 and RFOUTA2, and sent to the two echo receiving modules as local oscillator signals.

[0068] In specific implementation, the MAX2870 generates a stepped-frequency sine wave sequence under FPGA control. Each sequence cycle generates a total of 260 frequency points (step length), with a frequency step interval of 10MHz, a starting frequency point of 400MHz, and an ending frequency point of 3000MHz. One cycle sequence takes 13ms, the transmission frequency is 20kHz, and the time interval between two adjacent frequency pulses is 50us.

[0069] like Figure 3As shown, the MAX2870's key signals include the reference frequency input (REFIN), a three-wire serial communication interface (FSYN_CLK, FSYN_DATA, FSYN_LE), a chip enable (CE), VCO outputs (RFOUTA+, RFOUTA-), auxiliary VCO outputs (RFOUTB+, RFOUTB-), an RF shutdown (PDBRF), and a multiplexer output (MUXOUT). The MAX2870 has six internal registers for configuring its operating mode and parameters. In this embodiment, the reference frequency input REFIN is equal to 40MHz. Each time the chip is powered on, the FPGA sequentially assigns values ​​to registers R5, R4, R3, R2, R1, and R0 within the MAX2870. Under the combined influence of an external trigger signal and the PDBRF signal, the FPGA updates only R4 and R0 within the MAX2870 260 times during each frequency sweep cycle, at a 20kHz update frequency. This generates an increasing single-frequency signal, with the output frequency increasing by 10MHz each time.

[0070] The MAX2870 uses the RF shutdown pin, PDBRF, to control the output of sine wave pulses. When PDBRF is low, the RF output is muted, and when it is high, the RF signal is enabled. After a rising edge on PDBRF occurs, the FPGA sends 32 bits of data to the MAX2870's on-chip registers R4 and R0 via a three-wire serial port (FSYN_CLK, FSYN_DATA, and FSYN_LE) to program the frequency.

[0071] Set the MAX2870 registers R0 to R5 to the following parameters:

[0072] R1: 0X02001011, R2: 0X01001E12, R3: 0X00000011, R4: 0X0021010C, R5: 0X00580005. Note: Fixed and only needs to be set once.

[0073] Changed parameters: R0 is initialized to 0X00A80000.

[0074] Output frequency: minimum 400MHz, maximum 3000MHz, increasing in 10MHz intervals, a total of 260 frequency points.

[0075] f PFD =REF IN ×[(1+D) / (R×(1+T))]

[0076] RF OUT =[INT+(FRAC / MOD)]×(f PFD / RFDivider)

[0077] According to the above formula, the calculation method for the first frequency point is as follows:

[0078] fPFD=REFIN×[(1﹢D) / (R×(1﹢T))]=40M×[(1﹢0) / (2×(1﹢1))]=10MHz.

[0079] RFOUT=[640+(0 / 2)]×(10M / 16)=640×10M÷16=400MHz

[0080] After the register is assigned a value, the VCO generates a sinusoidal pulse at the set frequency point, which continues until the next rising edge of PDBRF arrives, when the register is assigned a new value and the frequency is stepped.

[0081] like Figure 3 Reference clock G1 uses a Taiyi voltage-controlled temperature-compensated crystal oscillator. R24, R25, R27, C50, C53, and C57 form a fast-lock loop filter topology. R17, R18, R19, C34, C39, and C41 form the RFOUTB RF output matching network, while R20, R22, R26, C48, C49, and C56 form the RFOUTA RF output matching network. Each of these generates a 400MHz to 3000MHz sinusoidal step-frequency signal. The RFOUTA signal is split into two paths by power divider U8, which then feeds the two receive channels.

[0082] C58, C59, and FB2 form a π-type filter to filter the 3.3V power supply output AVDD to power G1 (TSETBLSANF-40.00000) and U7 (MAX2870).

[0083] Regarding step S2, in one embodiment, the step of using the sinusoidal wave excitation signal to transmit the signal via radio frequency to obtain the radio frequency transmission signal includes:

[0084] like Figure 2 As shown, based on the sinusoidal wave excitation signal, it is filtered in turn through the first switching filter network, digital up-conversion is achieved through the orthogonal modulator, filtering is performed through the second switching filter network, and full-band filtering is performed through the full-band low-pass filter and the digital attenuator to obtain the RF transmission signal.

[0085] Specifically, it consists of a two-way switching filter network, a broadband quadrature modulator, a passband low-pass filter, and a digital attenuator. The quadrature modulator implements digital upconversion. Its baseband inputs (IBBP, IBBN, QBBP, and QBBN) are derived from a 6MHz sine wave signal generated by the host computer's DAC. The I and Q signals have a 90-degree phase shift. The LO local oscillator input is a sine wave excitation signal, RFOUTB, generated by the frequency synthesis module, with a frequency range of 400MHz to 3000MHz.

[0086] It should be noted that the RF transmitter module primarily consists of a filter switch network and an upconversion quadrature modulator. To suppress multiple harmonics and sidelobe interference, multiple filters are installed in the RF transmit path, performing multiple low-pass filtering operations for different frequency bands. The switch chip used is the SKYWORKS SKY13384-350LF single-pole, four-throw switch, which operates in the 0.02 GHz to 4.0 GHz frequency range and features low insertion loss and high isolation. It has two control pins, VC1 and VC2. The low-pass filter is the LFCN series from mini-circuits.

[0087] In specific implementation, Figure 4 , U3, U4, F3, F6, and F7 form the first-stage switch filter network, namely the first switch filter network. U3 and U4 are SKY13384-350LF, and F3, F6, and F7 are LFCN-1800+, LFCN-1000+, and LFCN-3400+ respectively. Figure 4 , R7, C5, R5, C6, D2, C4, R4 and R12, C13, R11, C14, D4, C12, R10 form the control signal network of the selection switch, such as Figure 5 、 Figure 6 , the switch control signal comes from CON_13 and CON_24 of the host computer. When CON_13 and CON_24 are high, T3 and T4 are high. At the same time, after the reverse of the switch field effect tubes D2 and D4, T1 and T2 are low. T1, T2, T3, and T4 are connected to the VC1 and VC2 control pins of U3 and U4. Control the synchronous selection between U3's RF2 and U4's RF3, U3's RF3 and U4's RF2, U3's RF4 and U4's RF1, and send the RF signal generated by the frequency synthesizer from the three low-pass filters F6, F3, and F7 in order from low to high frequency. The frequency band ranges are 410MHz~950MHz, 960MHz~1700MHz, and 1710MHz~3000MHz respectively. The control timing of CON_13 and CON_24 is Figure 10 shown.

[0088] In this embodiment, if Figure 5 、 Figure 6 , U2, U5, F1, F2, F5, F8 form the second-stage switch filter network, namely the second switch filter network. The RF signal after orthogonal modulation is subjected to a second frequency band filtering to further increase the purity of the spectrum. U2 and U5 are models SKY13384-350LF, and the models of F1, F2, F5, and F8 are LFCN-3400+, LFCN-1800+, LFCN-1000+, and LFCN-630+ respectively. As shown in the figure, R3, C2, R2, C3, D1, C1, R1 and R9, C8, R8, C9, D3, C7, and R6 form the control signal network of the selection switch, such as Figure 5 、 Figure 6 , the switch control signal comes from CON_68 and CON_57 of the host computer. When CON_68 and CON_57 are high, T6 and T5 are high. At the same time, after the reverse of the switch field effect transistors D1 and D3, T8 and T7 are low. T5, T6, T7, and T8 are connected to the VC1 and VC2 control pins of U2 and U5. Control the synchronous selection between U2's RF1 and U5's RF4, U2's RF2 and U5's RF3, U2's RF3 and U5's RF2, and U2's RF4 and U5's RF1, and send the RF signal generated by the frequency synthesizer out of the four low-pass filters F8, F5, F2, and F1 in order from low to high frequency. The frequency band ranges are 410MHz~630MHz, 640MHz~950MHz, 960MHz~1730MHz, and 1740MHz~3000MHz respectively. The control timing of CON_68 and CON_57 is Figure 11 shown.

[0089] In this embodiment, the RF signal passes through the second-stage switch filter network and is filtered again through a low-pass filter F4LFCN-3400+, and is sent to the transmitting antenna after passing through the attenuator U6 and the capacitor C33.

[0090] Regarding step S5, in this embodiment, obtaining a radar detection imaging result by mixing the local oscillator signal and the echo radio frequency signal includes:

[0091] The mixing process includes: performing AD on the pre-obtained intermediate frequency signal through mixing, performing signal processing on the radar target signal, and obtaining a radar detection imaging result;

[0092] The local oscillator signal is mixed with the pre-obtained echo radio frequency signal to generate an intermediate frequency signal, and the local oscillator signal is adjusted by an orthogonal modulator to obtain a radar detection imaging result.

[0093] In specific implementation, Figure 7 、 Figure 8 、 Figure 9 As shown in the figure, the RF echo is first amplified by 16.9dB by a low-noise amplifier (GVA-93+) in U18, powered by a balun, and then attenuated by 5dB by U17's GAT-5+. It then passes through a switch-filter network composed of U15, U16, F9, and F10. The control signal network for the gate switch, composed of R38, C85, R35, C86, D5, C82, and R34, generates the control signal CON_910 from the host computer. The echo RF signal and local oscillator signal are single-ended and need to be converted into double-ended signals by the TCM1-43X+ baluns in U12 and U13. They are then fed into the RFIN and LOIN terminals of the mixer in U11. The resulting intermediate frequency signals, IFOP and IFON, are fed into a low-pass filter composed of C68, L2, L4, C69, L3, L5, and C70. They are then buffered by the ADA4930 op amp in U9 and sent to the host computer for analog processing.

[0094] Example 2

[0095] See also Figure 12 , Figure 12 This is a structural diagram of a dual-channel stepped-frequency ground-penetrating radar radio frequency device provided by one embodiment of the present application, the device comprising:

[0096] The frequency synthesis module 11 is used to send register instructions to the frequency synthesizer through the SPI serial port to obtain the excitation signal generated by the frequency synthesizer, wherein the excitation signal includes: a sinusoidal wave excitation signal and a sinusoidal wave auxiliary excitation signal;

[0097] The frequency transmitting module 12 is used to use the sinusoidal wave excitation signal to obtain a radio frequency transmission signal through radio frequency transmission;

[0098] The echo receiving module 13 is used to receive the radio frequency transmission signal and obtain an echo radio frequency signal;

[0099] Used to utilize the sine wave auxiliary excitation signal to obtain a local oscillator signal through power distribution;

[0100] The local oscillator signal and the echo radio frequency signal are mixed to obtain a radar detection imaging result.

[0101] In one embodiment, the frequency transmission module 12 includes:

[0102] Based on the sinusoidal wave excitation signal, it is filtered in turn through the first switch filter network, digital up-conversion is achieved through the orthogonal modulator, filtering is performed through the second switch filter network, and full-band filtering is performed through the full-band low-pass filter and the digital attenuator to obtain the radio frequency transmission signal.

[0103] In one embodiment, the echo receiving module includes:

[0104] A first echo receiving channel 131, a second echo receiving channel 132, a low noise amplifier, a third switch filter network, a fourth switch filter network and an orthogonal modulator;

[0105] The echo radio frequency signal includes: a first echo radio frequency signal and a second echo radio frequency signal;

[0106] The first echo radio frequency signal is received and processed by the first echo receiving channel 131 to obtain a first intermediate frequency signal for output;

[0107] The second echo radio frequency signal is received and processed by the second echo receiving channel 132 to obtain a second intermediate frequency signal for output;

[0108] The first echo radio frequency signal is received and processed by the first echo receiving channel 131 to obtain a first intermediate frequency signal for output, including:

[0109] utilizing the first echo radio frequency signal to perform low noise amplification through a low noise amplifier, and then performing filtering processing through a third switch filter network;

[0110] Based on the processing result, mixing with the local oscillator signal is performed to generate an intermediate frequency signal;

[0111] Adopting an orthogonal modulator to adjust the local oscillator signal;

[0112] The second echo radio frequency signal is received and processed by the second echo receiving channel 132 to obtain a second intermediate frequency signal for output, including:

[0113] utilizing the second echo radio frequency signal, performing low noise amplification through a low noise amplifier, and then performing filtering processing through a fourth switch filter network;

[0114] Based on the result of the processing, mixing is performed with a pre-obtained local oscillator signal to generate a second intermediate frequency signal;

[0115] A radar detection imaging result is obtained based on the first intermediate frequency signal and the second intermediate frequency signal.

[0116] It should be noted that the first echo receiving channel 131 and the second echo receiving channel 132 are channels with the same function, structure and composition.

[0117] In practice, the two receiving channels share the same basic functionality and circuitry. High-IP3 active mixers are used for digital down-conversion, down-converting the echoed RF signal to the IF band. This generates the baseband signal's frequency response to the detected target under different carrier frequency excitations. This signal is then filtered through a loop filter and fed directly to the host computer's ADC for direct discretization. Digital down-conversion of the discrete data yields a digital IQ signal, which is then further analyzed. To ensure high amplitude and phase consistency between the two channels, the circuits share the same electrical design.

[0118] In the embodiments of this application, the MAX2870 frequency synthesizer with a built-in voltage-controlled oscillator (VCO) achieves smaller frequency spacing, higher operating frequency, and higher spectral quality compared to traditional DDS (direct digital synthesizers). The frequency synthesizer has a wide frequency bandwidth and high average power of the RF transmitted signal, requiring only a single antenna to simultaneously meet the requirements of detection depth and maximum resolution. The circuit's electrical structure is simple to design, with relatively low implementation difficulty, very low power consumption, and minimal size, reducing the difficulty of miniaturizing the device.

[0119] In this patent application, the key technologies of dual-channel stepped-frequency continuous-wave ground-penetrating radar are addressed. This patent focuses on the frequency synthesizer and dual-channel RF receiver module of the stepped-frequency continuous-wave radar. The frequency synthesizer has a frequency bandwidth of 2.6GHz, requiring only a single antenna to simultaneously meet the requirements of detection depth and maximum resolution. The dual-channel receiver design can simultaneously collect target amplitude and phase information from two channels, facilitating target imaging in back-end signal processing.

[0120] Example 3

[0121] See also Figure 13 , Figure 13 This is a diagram showing the composition of a dual-channel stepped-frequency ground-penetrating radar radio frequency device provided by one embodiment of the present application, the device comprising:

[0122] at least one processor 31; and

[0123] A memory 32 in communication with the at least one processor; wherein,

[0124] The memory stores instructions that can be executed by the at least one processor 31. The instructions are executed by the at least one processor 31 so that the at least one processor 31 can perform any one of the methods in the above embodiments.

[0125] It can be understood that the same or similar parts of the above embodiments can be referenced to each other, and the contents not described in detail in some embodiments can refer to the same or similar contents in other embodiments.

[0126] It should be noted that, in the description of this application, the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance. In addition, in the description of this application, unless otherwise specified, the meaning of "plurality" refers to at least two.

[0127] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code comprising one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may be performed out of the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present application belong.

[0128] It should be understood that various parts of the present application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used to implement: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application-specific integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0129] Those skilled in the art will understand that all or part of the steps in the method of the above embodiment can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable storage medium. When the program is executed, it includes one or a combination of the steps of the method embodiment.

[0130] In addition, the functional units in the various embodiments of the present application may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into a module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0131] The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc.

[0132] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0133] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A method for dual-channel stepped frequency ground penetrating radar radio frequency, characterized in that: The method comprises: Sending register instructions to the frequency synthesizer through the SPI serial port to obtain an excitation signal generated by the frequency synthesizer, wherein the excitation signal includes: a sinusoidal wave excitation signal and a sinusoidal wave auxiliary excitation signal; Utilizing the sinusoidal wave excitation signal to transmit a radio frequency signal, thereby obtaining a radio frequency transmission signal; Receive the radio frequency transmission signal to obtain an echo radio frequency signal; use the sine wave auxiliary excitation signal to obtain a local oscillator signal through power distribution; Using the local oscillator signal and the echo radio frequency signal, through frequency mixing processing, to obtain a radar detection imaging result; The receiving the radio frequency transmission signal to obtain an echo radio frequency signal includes: receiving a first echo radio frequency signal through a first echo receiving channel, and receiving a second echo radio frequency signal through a second echo receiving channel; wherein the first echo receiving channel and the second echo receiving channel are channels having the same function, structure, and composition; The method of obtaining a radar detection imaging result by mixing the local oscillator signal and the echo radio frequency signal includes: Using the local oscillator signal to mix with the first echo radio frequency signal and the second echo radio frequency signal respectively to obtain a first intermediate frequency signal and a second intermediate frequency signal; obtaining a radar detection imaging result based on the first intermediate frequency signal and the second intermediate frequency signal; The method of using the sinusoidal wave excitation signal to obtain a radio frequency transmission signal through radio frequency transmission includes: Based on the sinusoidal wave excitation signal, it is filtered in turn through the first switch filter network, digital up-conversion is achieved through the orthogonal modulator, filtering is performed through the second switch filter network, and full-band filtering is performed through the full-band low-pass filter and the digital attenuator to obtain the radio frequency transmission signal.

2. A dual-channel stepped-frequency ground penetrating radar radio frequency device, applied to the dual-channel stepped-frequency ground penetrating radar radio frequency method of claim 1, characterized in that: The device comprises: The frequency synthesis module is used to send register instructions to the frequency synthesizer through the SPI serial port to obtain the excitation signal generated by the frequency synthesizer, wherein the excitation signal includes: a sinusoidal wave excitation signal and a sinusoidal wave auxiliary excitation signal; A frequency transmitting module, configured to utilize the sinusoidal wave excitation signal to obtain a radio frequency transmitting signal through radio frequency transmission; An echo receiving module is used to receive the radio frequency transmission signal and obtain an echo radio frequency signal; Used to utilize the sine wave auxiliary excitation signal to obtain a local oscillator signal through power distribution; Using the local oscillator signal and the echo radio frequency signal, by mixing, to obtain a radar detection imaging result; The frequency transmission module includes: Based on the sinusoidal wave excitation signal, filtering is performed in sequence through a first switching filter network, digital up-conversion is achieved through an orthogonal modulator, filtering is performed through a second switching filter network, and full-band filtering is performed through a full-band low-pass filter and a digital attenuator to obtain a radio frequency transmission signal; The echo receiving module includes: a first echo receiving channel, a second echo receiving channel, a low noise amplifier, a third switch filter network, a fourth switch filter network and an orthogonal modulator; The echo radio frequency signal includes: a first echo radio frequency signal and a second echo radio frequency signal; The first echo radio frequency signal is received and processed through a first echo receiving channel to obtain a first intermediate frequency signal for output; The second echo radio frequency signal is received and processed through a second echo receiving channel to obtain a second intermediate frequency signal for output; The first echo radio frequency signal is received and processed through a first echo receiving channel to obtain a first intermediate frequency signal for output, including: utilizing the first echo radio frequency signal to perform low noise amplification through a low noise amplifier, and then performing filtering processing through a third switch filter network; Based on the processing result, mixing with the local oscillator signal is performed to generate an intermediate frequency signal; Adopting an orthogonal modulator to adjust the local oscillator signal; The second echo radio frequency signal is received and processed through a second echo receiving channel to obtain a second intermediate frequency signal for output, including: utilizing the second echo radio frequency signal, performing low noise amplification through a low noise amplifier, and then performing filtering processing through a fourth switch filter network; Based on the result of the processing, mixing is performed with a pre-obtained local oscillator signal to generate a second intermediate frequency signal; Obtaining a radar detection imaging result based on the first intermediate frequency signal and the second intermediate frequency signal; The echo receiving module also includes: The first echo receiving channel and the second echo receiving channel are channels with the same function, structure and composition.

3. A dual-channel stepped frequency ground penetrating radar radio frequency device, characterized in that: The device comprises: At least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the method described in claim 1.

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