Digital full-bandwidth direct forwarding radar transponder system and its working method

Abstract

The present invention provides a digital full-bandwidth direct-forwarding radar transponder system and its working method, which proposes a brand-new radar transponder system architecture and a corresponding new Morse code recognition scheme. The system of the present invention adopts a direct-forwarding system architecture, which combines digital broadband DRFM real-time forwarding technology and a line-replacing-by-point coding response architecture. The transmitting and receiving antennas are independent and work simultaneously, directly and indiscriminately encoding and forwarding all radar interrogation signals within the working frequency band, achieving Morse coding of the response information while retaining the complete waveform information. The system of the present invention can be equivalent to a target with special target characteristics. When the radar signals within the working frequency band irradiate this target, echo signals with specified Morse code modulation characteristics will be generated.

Description

Technical Field

[0001] The present invention belongs to the technical field of radio navigation, and particularly relates to a digital full-bandwidth direct forwarding radar transponder system and its working method. Background Art

[0002] A radar transponder is generally an aid to navigation used to identify buoys, lighthouses, ports, coasts, and other nautical objects. When a radar interrogation signal is detected, the radar transponder generates a Morse code response signal representing a specific meaning.

[0003] The existing radar transponders mainly have two implementation methods: frequency sweeping and frequency agility. Currently, the frequency-sweeping radar transponder has been phased out. The frequency-agile radar transponder contains additional circuits for measuring the frequency of each received interrogation pulse and quickly tuning the frequency of the response signal to be consistent with it.

[0004] The current mainstream frequency-agile radar transponder is an analog system transponder. Its working principle is as follows: the starting frequency and pulse width of the waveform to be responded are obtained through detection, main lobe detection, and frequency measurement circuits. After obtaining the starting frequency, a dot-frequency pulse response signal is generated by a voltage-controlled oscillator. The response waveform generated by the voltage-controlled oscillator is output after passing through a gating switch, and the gating time of the gating switch is controlled by the Morse code value.

[0005] The current mainstream radar transponder system has the following deficiencies:

[0006] 1) It is sensitive to the radar emission waveform and signal processing system, and can only be applied to narrow-band and simple modulation radar waveforms, and cannot adapt to the new system wide-band and complex modulation waveforms, which limits the application of the new system radar in the field of marine radar;

[0007] 2) The antenna adopts a time-division multiplexing system for transmitting and receiving. During the signal transmission period, it cannot respond to radar interrogations, which will cause the processing capacity to saturate in radar-intensive scenarios such as ports, thus losing the effective response to surrounding radar interrogation signals;

[0008] 3) It adopts a frequency measurement generation method. Before responding, parameters such as the frequency and amplitude of the radar interrogation signal need to be measured and identified, which is prone to misidentification when there are radars transmitting the same waveform around. Summary of the Invention

[0009] Aiming at the deficiencies of the existing technology and to solve the problem that the current radar transponder cannot respond to the new system radar with wide-band and complex modulation waveforms, the purpose of the present invention is to provide a digital full-bandwidth direct forwarding radar transponder system and its working method.

[0010] The traditional radar transponder system adopts a frequency measurement-generation system architecture, which uses the same antenna for transmission and reception. Before generating a response signal, it is necessary to detect the parameter characteristics of the input signal and match it with the existing radar parameters in the parameter library. When the input signal is determined to be a radar main lobe signal, a point frequency pulse response signal is generated according to the measured frequency parameters. The generated response waveform is output after passing through a gate switch, and the gating time of the gate switch is controlled by the Morse code value. Since the response waveform of the traditional radar transponder is a simple point frequency pulse signal, most of the waveform parameter information is lost. Therefore, the traditional radar transponder cannot respond to the new system radar waveform with a large bandwidth and complex modulation waveform.

[0011] In order to achieve the response to the new system radar, the system of the present invention proposes a new radar transponder system architecture and a corresponding new Morse code reading scheme. The system of the present invention adopts a direct forwarding system architecture, which combines the digital broadband DRFM real-time forwarding technology and the point-to-line coding response architecture. The transmitting and receiving antennas work independently and simultaneously, and all radar query signals within the working frequency band are directly encoded and forwarded without distinction, retaining the complete waveform information while realizing the Morse coding of the response information. The system of the present invention can be equivalent to a target with special target characteristics. When the radar signal within the working frequency band is irradiated to the target, an echo signal with specified Morse code modulation characteristics will be generated.

[0012] One of the cores of the system of the present invention also includes the implementation of Morse code modulation and the reading method of Morse code. The standard Morse code is constructed by three basic symbols: "dot", "space" and "dash". The "dot" and "dash" are solid lines, the length of the "dot" and "space" are equal, and the "dash" is three times the length of the "dot" or "space". The dots and dashes of the Morse code responded by the traditional radar transponder are displayed as radial solid lines on the radar, and the length meets the standard Morse coding rules. In order to achieve the response to the new system radar, the system of the present invention adopts a Morse code response architecture that uses dots instead of lines to replace the current Morse coding effect. The coding principle of the coding architecture is: 1) Several echo points replace the "dots" in the Morse code, and each echo point occupies one basic symbol unit; 2) The "dash" in the Morse code is replaced by an echo point three times that of the "dot", occupying three times the basic symbol unit of the "dot"; 3) The "space" in the Morse code occupies the same number of basic symbol units as the "dot"; 4) The distance displayed by each echo point on the radar depends on the radar resolution and is no longer equal to one basic symbol unit. According to the above coding principles, the recognition of Morse code no longer relies on the absolute distance ratio of "dots", "spaces" and "dashes", but is mainly based on the number of echo points and the distance between the starting points. As long as the basic symbol unit is larger than the minimum resolution distance unit of the radar, the received Morse code can be easily recognized.

[0013] The present invention specifically adopts the following technical solutions:

[0014] A digital full-bandwidth direct forwarding radar transponder system, characterized by comprising: an antenna system composed of a receiving antenna and a transmitting antenna, a radio frequency transceiver module composed of a radio frequency receiving link and a radio frequency transmitting link, and a baseband processing module including an ADC acquisition module, an FPGA processing module, and a DAC playback module;

[0015] The receiving antenna is used to receive the radar transmission signal within the working frequency band range from space, and the transmitting antenna is used to radiate the system response signal into space;

[0016] The radio frequency transceiver link shares a local oscillator module; the radio frequency receiving link is used to convert the radio frequency signal output by the receiving antenna into an intermediate frequency signal and output it to the ADC acquisition module of the baseband processing module; the radio frequency transmitting link is used to convert the intermediate frequency signal output by the DAC playback module of the baseband processing module into a radio frequency signal and output it to the transmitting antenna;

[0017] The ADC acquisition module converts the intermediate frequency analog signal output by the radio frequency receiver into a digital signal and sends it to the FPGA processing module; the DAC playback module converts the digital signal output by the FPGA processing module into an analog signal and sends it to the intermediate frequency analog input interface of the radio frequency transmitter; the FPGA processing module is used to implement quadrature down-conversion processing, envelope detection, Morse code modulation, and quadrature up-conversion processing of the ADC acquisition data.

[0018] Further, the Morse code modulation is implemented by three parts: a tapped delay line, a coding switch module, and a superposition module;

[0019] The tapped delay line adopts a multi-stage delay tap superposition architecture, and the delay modules are connected end to end to form a delay chain. The delay value of each stage of the delay module is the same and adjustable; the tap data is led out from the input of the tapped delay line and the output of each stage of the delay module to the coding switch module;

[0020] The coding switch module is a switch array, and each tap data corresponds to a switch for on / off. The on / off of the switch is controlled by the Morse code setting value; the Morse code setting value is obtained by looking up the Morse code mapping relationship table according to the Morse code symbol; the coding switch module outputs the selected tap data to the superposition module to participate in the superposition;

[0021] The superposition module superimposes all the input tap data into a 1-channel coded modulation waveform for output.

[0022] Further, the Morse code mapping relation table maps the "dot - dash - space" representation method corresponding to the Morse symbols to the Morse code setting values; the basic principle of mapping is that "dot" or "dash" is represented by 1, "space" is represented by 0 among "dot - dot", "dot - dash", "dash - dot", "dash - dash", the number of bit positions occupied by "dot" and "space" is the same, the number of bit positions occupied by "dash" is 3 times that of "dot" or "space", and the maximum length of the corresponding data of the Morse code setting value is occupied on the premise of satisfying the relative relationship of "dot", "dash", and "space".

[0023] Further, the operating frequency band range of the antenna system covers the 200 MHz bandwidth operating range of the entire radar transponder, and the isolation degree between the transmitting and receiving antennas is greater than the total system gain; the operating frequency band range of the RF transceiver link covers the 200 MHz bandwidth operating range of the entire radar transponder, and both the RF receiving link and the RF transmitting link include: filters, amplifiers, and mixers; the sampling rates of the ADC acquisition module and the DAC playback module need to be set to ensure that signals within the 200 MHz bandwidth range of the entire radar transponder can be acquired in the full frequency band.

[0024] Further, it also includes a radome for protecting each component module and preventing the environment from affecting and interfering with the working states of each component module.

[0025] Further, its working method includes the following steps:

[0026] Step S1: Power on and initialize;

[0027] Step S2: The receiving antenna receives the radar emission signal within the operating frequency band range from space;

[0028] Step S3: The RF receiving link filters, amplifies, mixes, filters, and amplifies the RF signal output by the receiving antenna and then outputs an intermediate - frequency signal;

[0029] Step S4: The ADC acquisition module of the baseband processing module performs analog - to - digital conversion on the intermediate - frequency analog signal output by the RF receiving link, converts it into a digital signal and outputs it;

[0030] Step S5: The FPGA processing module of the baseband processing module receives the digital signal output by the ADC acquisition module and performs DDC processing on it, shifting the received signal to the baseband;

[0031] Step S6: The Morse code modulation module in the FPGA processing module receives the baseband signal output by the DDC processing module and performs Morse code modulation processing on it;

[0032] Step S7: The DUC module in the FPGA processing module receives the output of the Morse code modulation module and performs up - conversion processing on it, and outputs an intermediate - frequency digital signal after processing;

[0033] Step S8: The DAC playback module of the baseband processing module performs digital-to-analog conversion on the intermediate-frequency digital signal output by the DUC module in the FPGA processing module, and outputs it after converting it into an analog intermediate-frequency signal;

[0034] Step S9: The radio frequency transmitting link filters, amplifies, mixes, filters, and amplifies the intermediate-frequency analog signal output by the DAC playback module of the baseband processing module, and then outputs a radio frequency signal;

[0035] Step S10: The transmitting antenna radiates the radio frequency signal output by the radio frequency transmitting link into space.

[0036] Compared with the prior art, the transceiver antennas of the present invention and its preferred solution are independent and work simultaneously, without the need to detect and identify the parameter characteristics of the input signal, and perform non-discriminatory coding and forwarding on all radar interrogation signals. Its beneficial effects include:

[0037] 1) Insensitive to the radar transmission waveform and signal processing system, and can respond to new system radar signals with complex modulation waveforms on the premise of being compatible with traditional radar signals, making it possible to apply new technologies and new systems to ship navigation radar systems;

[0038] 2) Can reliably respond to all received radar interrogation signals simultaneously, even if there is an overlapping part in the time domain or frequency domain for multiple radar interrogation signals;

[0039] 3) Has a natural ability to suppress radar transmission side lobes;

[0040] 4) Has a smaller system delay, that is, has a higher range accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The present invention will be further described in detail below with reference to the drawings and specific embodiments:

[0042] Figure 1 It is a block diagram of the system provided by the embodiment of the present invention;

[0043] Figure 2 It is a block diagram of the implementation of the Morse code modulation module in the embodiment of the present invention;

[0044] Figure 3 It is a schematic diagram of the Morse code modulation principle in the embodiment of the present invention;

[0045] Figure 4 It is a Morse code mapping relationship table in the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0046] To make the features and advantages of this patent more obvious and understandable, specific embodiments are given below for detailed description as follows:

[0047] The technical solution of the present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0048] In the following description, many specific details are set forth in order to provide a thorough understanding of the present invention. However, the present invention may be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited by the specific embodiments disclosed below.

[0049] As Figure 1 shown, the digital full-bandwidth direct forwarding radar transponder system provided in this embodiment includes the following parts:

[0050] (1) receiving antenna, (2) RF receiving link, (3) baseband processing module, (4) RF transmitting link, (5) transmitting antenna.

[0051] Among them, (1) the receiving antenna is used to receive the radar transmission signal within the working frequency band range from space;

[0052] (2) the RF receiving link is used to filter, amplify, mix, filter, and amplify the RF signal output by the receiving antenna and then output an intermediate frequency signal;

[0053] (3) the baseband processing module is used to perform ADC acquisition, digital down-conversion, Morse code modulation, digital up-conversion, and DAC playback on the intermediate frequency analog signal output by the RF receiving link;

[0054] (4) the RF transmitting link is used to filter, amplify, mix, filter, and amplify the intermediate frequency analog signal output by the DAC playback module of the baseband processing module and then output an RF signal;

[0055] (5) the transmitting antenna is used to radiate the RF signal output by the RF transmitting link into space.

[0056] In this embodiment, the connection relationship between the above components is as follows: from (1) to (5), the output of the previous module is sequentially connected to the input of the next module, thus forming the basic composition of the system.

[0057] The following will separately describe each component of the system in this embodiment.

[0058] Antenna System: The antenna system consists of a receiving antenna and a transmitting antenna. The operating frequency band range of the antenna covers the entire 200MHz bandwidth operating range of the radar transponder (S band: 2.9G - 3.1G, X band: 9.3G - 9.5G). The receiving antenna is used to receive radar emission signals within the operating frequency band range from space, and the transmitting antenna is used to radiate the system response signal into space. Since the transmitting and receiving antennas need to work simultaneously, to avoid system self-oscillation, the isolation between the transmitting and receiving antennas must be greater than the total system gain. The system gain is proportional to the response distance. To increase the response distance, the design of high-isolation transmitting and receiving antennas is crucial for this system. Two feasible ways for the design of high-isolation antennas are: 1) Optimize the parameters and layout of the transmitting and receiving antennas themselves; 2) Add a cancellation branch, or the above two ways can be combined. The transmitting and receiving antennas need to be installed vertically one above the other, both in a basically vertical state, and the farther apart the better. For compactness, a radio signal isolation board can be added between the transmitting and receiving antennas in the structural design. The isolation board is made of materials such as metal that have an isolation or shielding effect on radio signals. The transmitting and receiving antennas are approximately on a vertical line or slightly offset. The isolation board is generally circular, square, etc. The center of the isolation board is approximately on the connection line between the two antennas and close to the middle position between the two antennas, approximately in a horizontal state and perpendicular to the antennas to avoid system self-oscillation, thereby increasing the transmission power to achieve the effect of increasing the response distance.

[0059] RF Transceiver Module: The RF transceiver module consists of an RF receiving link and an RF transmitting link. The operating frequency band range of the RF transceiver link covers the entire 200MHz bandwidth operating range of the radar transponder (S band: 2.9G - 3.1G, X band: 9.3G - 9.5G). Both the RF receiving link and the RF transmitting link are composed of core devices such as filters, amplifiers, mixers, etc., and the RF transceiver link shares a local oscillator module. The RF receiving link is used to convert the RF signal output by the receiving antenna into an intermediate frequency signal and output it to the ADC acquisition module of the baseband processing module, and the RF transmitting link is used to convert the intermediate frequency signal output by the DAC playback module of the baseband processing module into an RF signal and output it to the transmitting antenna.

[0060] Baseband Processing Module: The baseband processing module mainly consists of an ADC acquisition module, an FPGA processing module, and a DAC playback module. The ADC acquisition module converts the intermediate frequency analog signal output by the RF receiver into a digital signal and sends it to the FPGA processing module. The DAC playback module converts the digital signal output by the FPGA processing module into an analog signal and sends it to the intermediate frequency analog input interface of the RF transmitter. The sampling rates of the ADC acquisition module and the DAC playback module need to be set to ensure that the signals within the 200MHz bandwidth range of the entire radar transponder can be acquired in the full frequency band. The FPGA processing module is the core module of the system of the present invention, mainly realizing the quadrature down-conversion processing, envelope detection, Morse code modulation, and quadrature up-conversion processing of the ADC-acquired data.

[0061] As shown Figures 2 to 4 in the figure, among which, Morse code modulation is one of the core processing links of the system in this embodiment, and it consists of three parts: a tapped delay line, an encoding switch, and a superposition module. The tapped delay line is implemented by using a multi-stage delay tap superposition architecture. The delay modules are connected end to end to form a delay chain. The delay value of each stage of the delay module is the same and can be set. For optimizing the display effect, each stage of the delay module can be further divided into multiple sub-delays internally. The tap data is led out from the input of the tapped delay line and the output of each stage of the delay module to the encoding switch module; the encoding switch module is a switch array, and each path of tap data corresponds to a make-break switch. The make-break of the switch is controlled by the Morse code setting value. The Morse code setting value is obtained according to the Morse code symbol by looking up the Morse code mapping relation table compiled by the present invention. The Morse code mapping relation table is a table of the corresponding relationship between Morse code symbols and Morse code setting values. The Morse code symbols include A~Z, 0~9, NW, NE, SW, SE. The number of bits of the Morse code setting value is the same as the number of paths of the tap data, and they are sorted from high to low in sequence. Each 1 bit of the Morse code setting value is called a basic symbol unit, and each 1 bit of the Morse code setting value controls a make-break switch in the encoding switch module. The function of the Morse code mapping relation table is to map the "dot-dash-space" representation method corresponding to the Morse symbol into the Morse code setting value. The basic principle of the mapping is that "dot" or "dash" is represented by 1, and "space" is represented by 0 among "dot-dot", "dot-dash", "dash-dot", "dash-dash". The number of bits occupied by "dot" and "space" is the same, and the number of bits occupied by "dash" is 3 times the number of bits occupied by "dot" or "space", and it occupies the maximum length of the corresponding data of the Morse code setting value under the premise of satisfying the relative relationship of "dot", "dash", and "space". The output of the encoding switch module selects the tapped data to participate in the superposition in the superposition module; the superposition module superimposes all the input tapped data into a path of encoded modulation waveform for output.

[0062] Radome: The radome is used to protect other parts of the system of the present invention and prevent the environment from affecting and interfering with the working state of other parts. At the same time, the design of the radome has a certain impact on the isolation degree between the transmitting and receiving antennas of the system of the present invention. The design of the radome and the design of the transmitting and receiving antennas should be considered comprehensively.

[0063] Based on the above system and related principles, preferably, this embodiment provides a more specific design and working method under this system architecture:

[0064] 1) Power on the system and perform initialization;

[0065] 2) Send the Morse code configuration value: 19’b111_1111_1100_0111_0000 (Morse code: N) and the delay value of the tapped delay line: 500 (corresponding to the basic symbol unit length: 500 * 4 ns = 2 us) to the Morse code modulation module of the baseband processing module;

[0066] 3) The receiving antenna (X: 9.3 - 9.5 GHz, omnidirectional, horizontal polarization, elevation angle 22°, gain 6 dBi, isolation between transmitting and receiving antennas 85 dB) receives the radar transmission signal within the working frequency band range from space.

[0067] 4) The RF receiving link (input: 9.3 - 9.5 GHz, output: 600 - 800 MHz, gain: 30 dB) filters, amplifies, mixes, filters, and amplifies the RF signal output by the receiving antenna and then outputs an intermediate frequency signal.

[0068] 5) The ADC acquisition module of the baseband processing module (sampling rate 1 Gbps) performs analog-to-digital conversion on the intermediate frequency analog signal output by the RF receiving link, converts it into a digital signal (4 channels in parallel @ 250 MHz), and outputs it.

[0069] 6) The FPGA processing module of the baseband processing module (FPGA model: xc7v325t-ffg900) receives the digital signal output by the ADC acquisition module and performs DDC processing on it (local oscillator frequency 700 MHz, filter bandwidth 200 MHz, 4-fold decimation), and shifts the received signal to the baseband (1 channel signal, sampling rate 250 Mbps).

[0070] 7) The Morse code modulation module in the FPGA processing module receives the baseband signal output by the DDC processing module and performs Morse code modulation processing on it.

[0071] 8) The DUC module in the FPGA processing module (local oscillator frequency 700 MHz, filter bandwidth 200 MHz, 4-fold interpolation) receives the output of the Morse code modulation module and performs up-conversion processing on it, and then outputs an intermediate frequency digital signal (4 channels in parallel @ 250 MHz).

[0072] 9) The DAC playback module of the baseband processing module performs digital-to-analog conversion on the intermediate frequency digital signal output by the DUC module in the FPGA processing module, converts it into an analog intermediate frequency signal, and then outputs it (1 channel, 600 - 800 MHz).

[0073] 10) The RF transmitting link (input: 600 - 800 MHz, output: 9.3 - 9.5 GHz, gain: 50 dB) filters, amplifies, mixes, filters, and amplifies the intermediate frequency analog signal output by the DAC playback module in the baseband processing module and then outputs an RF signal.

[0074] 11) The transmitting antenna (X: 9.3 - 9.5 GHz, omnidirectional, horizontal polarization, elevation angle 22°, gain 6 dBi, isolation between transmitting and receiving antennas 85 dB) radiates the RF signal output by the RF transmitting link into space.

[0075] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention in any other form. Any person skilled in the art may use the technical content disclosed above to make changes or modifications into equivalent embodiments with equivalent changes. However, as long as it does not depart from the technical content of the technical solution of the present invention, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention still fall within the protection scope of the technical solution of the present invention.

[0076] Obviously, the above embodiments of the present invention are only examples for clearly explaining the present invention, and are not intended to limit the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or variations can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A digital full-bandwidth direct forwarding radar transponder system, characterized in that, Comprising: An antenna system consisting of a receiving antenna and a transmitting antenna, a radio frequency transceiver module consisting of a radio frequency receiving link and a radio frequency transmitting link, and a baseband processing module including an ADC acquisition module, an FPGA processing module, and a DAC playback module; The receiving antenna is used to receive radar emission signals within the working frequency band range from space, and the transmitting antenna is used to radiate the system response signal into space; The radio frequency transceiver module shares a local oscillator module; The radio frequency receiving link is used to convert the radio frequency signal output by the receiving antenna into an intermediate frequency signal and output it to the ADC acquisition module of the baseband processing module; The radio frequency transmitting link is used to convert the intermediate frequency signal output by the DAC playback module of the baseband processing module into a radio frequency signal and output it to the transmitting antenna; The ADC acquisition module converts the intermediate frequency analog signal output by the radio frequency receiver into a digital signal and sends it to the FPGA processing module; the DAC playback module converts the digital signal output by the FPGA processing module into an analog signal and sends it to the intermediate frequency analog input interface of the radio frequency transmitter; the FPGA processing module is used to implement quadrature down-conversion processing, envelope detection, Morse code modulation, and quadrature up-conversion processing of the ADC acquisition data; The Morse code modulation is implemented by three parts: a tapped delay line, a coding switch module, and a superposition module; The tapped delay line adopts a multi-stage delay tap superposition architecture, and the delay modules are connected end to end to form a delay chain. The delay value of each stage of the delay module is the same and adjustable; the tap data is led out from the input of the tapped delay line and the output of each stage of the delay module to the coding switch module; The coding switch module is a switch array, and each tap data corresponds to a on-off switch. The on-off of the switch is controlled by the Morse code encoding setting value; the Morse code encoding setting value is obtained by looking up the Morse code mapping relationship table according to the Morse code symbol; the coding switch module outputs the selected tap data to the superposition module to participate in the superposition; The superposition module superimposes all the input tap data into a 1-channel coded modulation waveform and outputs it.

2. The digital full-bandwidth direct forwarding radar transponder system according to claim 1, characterized in that: The Morse code mapping relationship table maps the "dot-dash-space" representation method corresponding to the Morse code symbol into the Morse code encoding setting value; the basic principle of the mapping is that "dot" or "dash" is represented by 1, and "space" is represented by 0 between "dot-dot", "dot-dash", "dash-dot", "dash-dash". The number of bits occupied by "dot" and "space" is the same, and the number of bits occupied by "dash" is 3 times the number of bits occupied by "dot" or "space". Under the premise of satisfying the relative relationship of "dot", "dash", and "space", it occupies the maximum length of the data corresponding to the Morse code encoding setting value.

3. The digital full-bandwidth direct forwarding radar transponder system according to claim 1, characterized in that: The working frequency band range of the antenna system covers the 200MHz bandwidth working range of the entire radar transponder, and the isolation degree between the receiving and transmitting antennas is greater than the total system gain; the working frequency band range of the radio frequency transceiver module covers the 200MHz bandwidth working range of the entire radar transponder. The radio frequency receiving link and the radio frequency transmitting link both include: a filter, an amplifier, and a mixer; the sampling rates of the ADC acquisition module and the DAC playback module need to be set to ensure that signals within the 200MHz bandwidth range of the entire radar transponder can be acquired in the full frequency band.

4. The digital full-bandwidth direct forwarding radar transponder system according to claim 1, wherein: It also includes a radome for protecting each component module and preventing the environment from affecting and interfering with the working state of each component module.

5. The working method of the digital full-bandwidth direct forwarding radar transponder system according to claim 2, characterized in that, It includes the following steps: Step S1: Power on and initialize. Step S2: The receiving antenna receives the radar emission signal within the working frequency band from space. Step S3: The RF receiving link filters, amplifies, mixes, filters, and amplifies the RF signal output by the receiving antenna and then outputs an intermediate frequency signal. Step S4: The ADC acquisition module of the baseband processing module performs analog-to-digital conversion on the intermediate frequency analog signal output by the RF receiving link, converts it into a digital signal and outputs it. Step S5: The FPGA processing module of the baseband processing module receives the digital signal output by the ADC acquisition module and performs DDC processing on it, shifting the received signal to the baseband. Step S6: The Morse code modulation module in the FPGA processing module receives the baseband signal output by the DDC processing module and performs Morse code modulation processing on it. Step S7: The DUC module in the FPGA processing module receives the output of the Morse code modulation module and performs up-conversion processing on it, and outputs an intermediate frequency digital signal after processing. Step S8: The DAC playback module of the baseband processing module performs digital-to-analog conversion on the intermediate frequency digital signal output by the DUC module in the FPGA processing module, converts it into an analog intermediate frequency signal and then outputs it. Step S9: The RF transmitting link filters, amplifies, mixes, filters, and amplifies the intermediate frequency analog signal output by the DAC playback module of the baseband processing module and then outputs an RF signal. Step S10: The transmitting antenna radiates the RF signal output by the RF transmitting link into space.

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