A method and device for jamming complex radar signals based on time-sharing transmission and reception on airborne

Abstract

The present invention discloses an airborne interference method and device for complex radar signals based on time-sharing transmission and reception. The method includes the following steps: a digital module receives radar radio frequency signals and performs down-conversion and channelization processing to obtain detection signals and PDW data; a main control module performs sorting processing on the PDW data to obtain the number of radars and corresponding EDW data; the main control module generates sampling gates, distance gates, window gates, and transceiver gates, etc. The parameters of the window gates include window protection duration, window duration, and window interval duration; the digital module controls the timing of radar radio frequency signal reception and radio frequency interference signal transmission through the transceiver gates. The method of the present invention realizes accurate interference within the entire distance segment, solving the problem that the existing interference logic cannot adapt to complex waveforms.

Description

Technical Field

[0001] The present invention belongs to the technical field of electronic countermeasures, and in particular relates to an interference method and device for airborne complex radar signals based on time-sharing transmission and reception. Background Art

[0002] To meet modern training requirements, jamming and target simulation for early warning radars is often performed by mounting jamming equipment on drones, allowing for a wider range of training scenarios. However, these scenarios present the following challenges: 1. Because the jamming equipment is mounted on a drone, the space is limited, requiring transmitter-receiver isolation; and 2. How to adapt to complex radar waveforms and perform jamming or target simulation.

[0003] To address the isolation issue, existing methods often design the system as a time-sharing system, where both transmit and receive share a single antenna and the devices operate in separate timeframes. This approach can address the isolation issue between the transmit and receive antennas in a simultaneous system, but it doesn't consider the isolation issue within the device cavity during signal transmission. If an interfering signal radiates to the receiving branch through microwaves or the power amplifier cavity during transmission, it can cause the receiving branch to be falsely triggered, disrupting the interference timing. Interference resources are completely occupied by both the transmitter and receiver, resulting in a very poor overall interference effect.

[0004] Moreover, the waveforms of existing radars are mostly complex waveforms. For example, early warning radars are mostly combinations of blind-filling pulses and main pulses, and the two pulses appear one after another in time sequence. The conventional interference method of existing jammers with time-sharing transmission and reception is to receive after the rising edge of the radar detection arrives, and the reception time is set manually. After the reception is completed, the transmission is switched to the transmission time, which is also set manually. If the transmission time is set shorter to ensure that both the blind-filling pulse and the main pulse can be collected, the distance covered by the interference is limited (the time corresponds to the distance), and it is basically only short-range; if the interference time is set longer to make the interference as complete as possible, the main pulse will not be collected, and all distance segments of the blind pulse and the main pulse cannot be covered, resulting in poor interference effect. Summary of the Invention

[0005] Technical purpose: In order to solve the above technical problems, the present invention proposes a method for jamming complex radar signals based on time-sharing transmission and reception, which can solve the problem of poor interference effect caused by self-excitation in the cavity under the time-sharing transmission and reception logic, and the problem that the existing jamming logic cannot adapt to complex waveforms.

[0006] Technical solution: To achieve the above technical objectives, the present invention adopts the following technical solution:

[0007] A method for jamming complex radar signals on an airborne basis based on time-sharing transmission and reception, comprising the steps of:

[0008] Receive radar RF signals and perform down-conversion and channelization processing to obtain detection signals and PDW data;

[0009] Sorting the PDW data to obtain the number of radars and corresponding EDW data, where the EDW data includes the type, frequency, and repetition data of the radar signal, as well as the pulse width of the blind pulse and main pulse of the early warning radar radio frequency signal;

[0010] Generate a sampling gate, a windowing gate, a range gate, a transceiver gate, and an interference gate based on the detection signal and EDW data;

[0011] Controlling the reception of radar radio frequency signals according to the transceiver gate, and sampling and storing the received radar radio frequency signals according to the sampling gate;

[0012] According to the interference gate and detection results, the sampled and stored data of the radar RF signal is read and modulated to obtain the intermediate frequency interference signal;

[0013] Performing up-conversion and digital-to-analog conversion on the intermediate frequency interference signal to obtain a radio frequency interference signal, and controlling the emission of the radio frequency interference signal according to the transceiver gate;

[0014] The sampling gate, windowing gate, range gate, transceiver gate, and interference gate are obtained by the following steps:

[0015] generating a sampling wave gate according to the detection signal;

[0016] Generate a window gate based on the detection signal and EDW data, wherein the parameters of the window gate include the window protection time t1, the window time t2 and the window interval time t3;

[0017] The main control module sets the initial distance and the end distance according to the detection signal and the EDW data, and generates a range gate by combining the window gate.

[0018] The main control module generates a transceiver gate for controlling the state switching of the transceiver antenna according to the detection signal, the window gate and the distance gate. The transceiver gate is in the receiving state when the detection signal exists, or the distance gate is at a low level, or the window gate is at a low level; the transceiver gate is in the transmitting state when the detection signal exists and the window gate and the distance gate are both at a high level.

[0019] Preferably, the window protection duration t1 is the pulse width length of the main pulse with the largest number of occurrences and the largest pulse width, the window interval duration t3 is set according to the repetition rate of the radar RF signal, and the window duration t2 is set according to the processing time required for transmission to reception.

[0020] Preferably, the timing logic of the window gate is to cycle through the following process:

[0021] When the rising edge of the detection signal arrives, the level is pulled high and maintained for a period of t1;

[0022] After the duration t1 ends, the level is pulled low and maintained for the duration t2;

[0023] After the duration t2 ends, the level is pulled high and maintained for the duration t3-t2;

[0024] Pull the level low until the next rising edge of the detection signal is detected.

[0025] Preferably, during transmission, the interference method sets the attenuation coefficients of all attenuation components of the receiving branch to the maximum, or closes the receiving branch.

[0026] An airborne jamming device for complex radar signals based on time-sharing transmission and reception, comprising:

[0027] A receiving branch, used for receiving radar radio frequency signals;

[0028] A microwave down-conversion module is used to down-convert the received radar radio frequency signal;

[0029] The digital module is equipped with an ADC analog-to-digital conversion module for sampling and processing the analog data output by the microwave down-conversion module; a digital channelization module for channelizing the analog data output by the ADC module to obtain PDW data; a signal detection module for obtaining a detection signal; an instantaneous amplitude and phase measurement module for detecting the amplitude and phase of the signal; a modulation module for reading the sampled and stored data of the radar RF signal according to the interference wave gate and the detection result, and obtaining a digital intermediate frequency interference signal after modulation; and a digital-to-analog conversion module for converting the digital intermediate frequency interference signal into an analog intermediate frequency interference signal.

[0030] The main control module is provided with a sorting module for sorting and processing the PDW data to obtain the number of radars and the corresponding EDW data. The EDW data includes the type, frequency, and repetition data of the radar signal, as well as the pulse width of the blind pulse and main pulse of the early warning radar RF signal; the gate generation module is used to generate a sampling gate, a windowing gate, a range gate, a transceiver gate, and an interference gate based on the detection signal and EDW data;

[0031] The microwave down-conversion module performs up-conversion processing on the analog intermediate frequency interference signal to obtain the radio frequency interference signal;

[0032] A transmitting branch, configured to transmit the radio frequency interference signal;

[0033] a transceiver antenna, shared by the receiving branch and the transmitting branch;

[0034] The transceiver power amplifier module is used to control the switching of the receiving and transmitting states of the transceiver antenna according to the transceiver wave gate.

[0035] Beneficial effects: Due to the adoption of the above technical solution, the present invention has the following beneficial effects:

[0036] The method of the present invention improves the interference logic and can accurately implement interference within the entire distance range. It has better effects than conventional interference and can solve the problem of poor interference effect caused by self-excitation in the cavity under the time-sharing logic of transmission and reception, as well as the problem that the existing interference logic cannot adapt to complex waveforms. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a timing diagram of the jamming method for complex radar signals onboard based on time-sharing transmission and reception proposed in Example 1;

[0038] Figure 2 This is a structural diagram of the airborne jamming device for complex radar signals based on time-sharing transmission and reception proposed in Example 2. DETAILED DESCRIPTION

[0039] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0040] Example 1

[0041] This embodiment proposes an airborne jamming method for complex radar signals based on time-sharing transmission and reception, including the following steps:

[0042] Receive radar RF signals and perform down-conversion and channelization processing to obtain detection signals and PDW data;

[0043] The PDW data is sorted and processed to obtain the number of radars and the corresponding EDW data. The EDW data contains the type, frequency, and repetition data of the radar signal, as well as the pulse width of the blind pulse and main pulse of the early warning radar RF signal;

[0044] Generate sampling gate, window gate, range gate, transceiver gate and interference gate according to detection signal and EDW data;

[0045] Controlling the reception of radar radio frequency signals according to the transmit and receive gates, and sampling and storing the received radar radio frequency signals according to the sampling gates;

[0046] According to the interference gate and detection results, the sampled and stored data of the radar RF signal is read and modulated to obtain the intermediate frequency interference signal;

[0047] The intermediate frequency interference signal is up-converted and digital-to-analog converted to obtain a radio frequency interference signal, which is then sent out according to the transmit and receive gate control.

[0048] The complex radar in this invention primarily refers to early warning radar signals, which contain blind pulses and main pulses, or shield pulses and main pulses. Based on the detection signal and EDW data, a sampling gate, windowing gate, range gate, transceiver gate, and interference gate are generated. The process for acquiring EDW data from radar RF signals can be implemented using the method described in patent application number CN116466305A, entitled "An Integrated Method for Radar Signal Interference Detection," and the associated hardware of the digital + master control module.

[0049] After obtaining the radar's EDW data, for the early warning radar with blind spot pulses, interference is performed according to the following scheme.

[0050] The present invention adds a windowing logic and introduces a windowing gate. The parameters of the windowing gate include the windowing protection time t1, the windowing time t2, and the windowing interval time t3.

[0051] The window protection duration t1 is calculated based on the pulse width of the most frequent and longest main pulse. Specifically, the data for the window protection duration is derived from the master control's statistical analysis of the EDW, automatically setting the window protection duration based on the most frequent and longest pulse width. Because the interval between the early warning radar's blind spot pulse and the main pulse is the sum of the main and blind spot pulse widths, using the main pulse as the window protection duration ensures neither interference from the blind spot pulse nor repeated sampling within the main pulse.

[0052] The windowing interval t3 and windowing duration t2 can be set as needed. Specifically, the windowing interval can be set based on the radar's repetition rate, and the windowing duration can be set based on the processing time required to transition from transmit to receive. For example, if the radar has a 3ms repetition rate, a 500µs windowing interval can be set. A 1µs windowing duration is generally sufficient.

[0053] This invention uses windowing logic to detect the arrival of the next pulse. After the windowing protection period, the system opens windows at regular intervals to receive external signals. As soon as a radar detection signal is detected, reception is immediately resumed, allowing the arrival of the next pulse to be detected. By sensing the arrival of the next pulse and sampling it, no signal is missed. The windowing protection period ensures that the radar signal is sampled as completely as possible.

[0054] The main interference timing is as follows Figure 1 As shown:

[0055] When the radar signal arrives, a detection signal is generated. When the rising edge of the detection signal is detected, the signal is sampled. The sampling is performed according to the set sampling time or until the detection is completed.

[0056] A distance gate is generated based on the set initial and final interference distances. The detection signal starts counting at its rising edge. When the initial distance is reached, the gate is pulled high until the final distance gate is pulled low.

[0057] According to the newly added windowing logic, when the rising edge of the detection arrives, the counting starts. After counting to the windowing protection time, the window is opened by default (the level is pulled low) for the windowing time. Then the counting starts again. After counting to "windowing interval time - windowing time", the window is opened again, and this cycle repeats.

[0058] The logic of the transmit and receive gates is that when there is external detection, the distance gate is low, or the window gate is low, the signal is in the receive state. The signal is in the transmit state only when the distance gate is high, the window gate is high, and there is no detection.

[0059] The present invention automatically generates a distance gate by setting an initial distance and an end distance, then combines the distance gate with a window gate and a detection signal to determine a transmitting and receiving gate, and automatically switches transmitting and receiving according to the gate, thereby ensuring that both the blind pulse and the main pulse can be collected, and ensuring transmission within the time between the blind pulse and the main pulse, thereby ensuring the interference effect.

[0060] Example 2

[0061] like Figure 2 As shown, this embodiment provides a radar signal jammer, comprising a transceiver antenna, a transceiver power amplifier module, a transceiver power amplifier, a receiving branch, a transmitting branch, a microwave down-conversion module, a microwave up-conversion module, a digital module, and a main control module. The transmitter and receiver share a single transceiver antenna, and based on a time-sharing transmission and reception mechanism, the jammer can operate even on a drone.

[0062] The main functions of the transceiver antenna are to radiate, receive and transmit signals.

[0063] The function of the input power amplifier module is to realize the time sharing of transmission and reception according to the transmit and receive wave gates generated by the digital module, and to amplify the signal.

[0064] The function of microwave down-conversion is to convert the signal from radio frequency to intermediate frequency.

[0065] The function of microwave up-conversion is to convert the signal from intermediate frequency to radio frequency;

[0066] The functions of the digital + main control module are: reconnaissance information processing, generation of intermediate frequency interference signals, interference timing control, etc.

[0067] Specifically, the digital module is provided with an ADC analog-to-digital conversion module for sampling and processing the analog data output by the microwave down-conversion module; a digital channelization module for channelizing the analog data output by the ADC module to obtain PDW data; a signal detection module for obtaining a detection signal; an instantaneous amplitude and phase measurement module for detecting the amplitude and phase of the signal; a modulation module for reading the sampled and stored data of the radar RF signal according to the interference wave gate and the detection result, and obtaining a digital intermediate frequency interference signal after modulation; and a digital-to-analog conversion module for converting the digital intermediate frequency interference signal into an analog intermediate frequency interference signal.

[0068] The main control module is equipped with a sorting module for sorting and processing PDW data to obtain the number of radars and the corresponding EDW data. The EDW data contains the type, frequency, and repetition data of the radar signal, as well as the pulse width of the blind pulse and main pulse of the early warning radar RF signal; the gate generation module is used to generate the sampling gate, window gate, range gate, transceiver gate and interference gate according to the detection signal and EDW data.

[0069] The main control module generates a sampling gate based on the detection signal. A windowing gate is generated based on the detection signal and EDW data. Initial and ending distances are set based on the detection signal and EDW data, and combined with the windowing gate, a range gate is generated. Based on the detection signal, windowing gate, and range gate, a transceiver gate is generated to control the state switching of the transmit and receive antennas. The transceiver gate is raised only when the detection signal is present and both the windowing gate and range gate are high, indicating that the transmit and receive antennas have switched to the transmit state. This ensures that both the blind pulse and the main pulse of the radar signal are captured, and that transmission can be guaranteed during the time between the blind pulse and the main pulse, improving the jamming effect.

[0070] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the above embodiments do not limit the present invention in any form, and any technical solutions obtained by equivalent replacement or equivalent transformation fall within the scope of protection of the present invention.

Claims

1. An airborne jamming method for complex radar signals based on time-sharing transmission and reception, characterized in that: Includes steps: Receive radar RF signals and perform down-conversion and channelization processing to obtain detection signals and PDW data; Sorting and processing the PDW data to obtain the number of radars and corresponding EDW data, wherein the EDW data includes the type, frequency, and repetition data of the radar signal; Generate a sampling gate, a window gate, a distance gate, a transceiver gate and an interference gate according to the detection signal and the EDW data; Controlling the reception of radar radio frequency signals according to the transceiver gate, and sampling and storing the received radar radio frequency signals according to the sampling gate; According to the interference wave gate and detection results, the sampled and stored data of the radar RF signal is read, and the intermediate frequency interference signal is obtained after modulation; Performing up-conversion and digital-to-analog conversion processing on the intermediate frequency interference signal to obtain a radio frequency interference signal, and controlling the emission of the radio frequency interference signal according to the transceiver gate; The sampling gate, the window gate, the distance gate, the transceiver gate and the interference gate are obtained by the following steps: generating a sampling wave gate according to the detection signal; Generate a window gate according to the detection signal and EDW data, wherein the parameters of the window gate include window protection time t1, window time t2 and window interval time t3; The main control module sets the initial distance and the end distance according to the detection signal and the EDW data, and generates a distance gate in combination with the window gate; The main control module generates a transceiver gate for controlling the state switching of the transceiver antenna according to the detection signal, the window gate and the distance gate. The transceiver gate is in the receiving state when the detection signal exists, or the distance gate is at a low level, or the window gate is at a low level; the transceiver gate is in the transmitting state when the detection signal exists and the window gate and the distance gate are both at high levels.

2. The method for jamming an airborne complex radar signal based on time-sharing transmission and reception according to claim 1 is characterized in that: The window protection time length t1 is the pulse width length of the main pulse with the largest number of occurrences and the largest pulse width, the window interval time length t3 is set according to the repetition rate of the radar RF signal, and the window time length t2 is set according to the processing time required for transmission to reception.

3. The method for jamming complex radar signals based on time-sharing transmission and reception according to claim 2 is characterized in that: The timing logic of the window gate is to cycle the following process: When the rising edge of the detection signal arrives, the level is pulled high and maintained for a period of t1; After the duration t1 is over, the level is pulled low and maintained for the duration t2; After the duration t2 is over, the level is pulled high and maintained for the duration t3-t2; Pull the level low until the next rising edge of the detection signal is detected.

4. The method for jamming complex radar signals based on time-sharing transmission and reception according to claim 1 is characterized in that: The interference method sets the attenuation coefficients of all attenuation components of the receiving branch to the maximum during transmission, or closes the receiving branch.

5. An airborne jamming device for complex radar signals based on time-sharing transmission and reception, characterized in that: include: A receiving branch, used for receiving radar radio frequency signals; A microwave down-conversion module is used to down-convert the received radar radio frequency signal; The digital module is provided with an ADC analog-to-digital conversion module for sampling and processing the analog data output by the microwave down-conversion module; The digital channelization module is used to perform channelization processing on the analog data output by the ADC module to obtain PDW data; the signal detection module is used to obtain the detection signal; the instantaneous amplitude and phase measurement module is used to detect the amplitude and phase of the signal; The modulation module is used to read the sampled and stored data of the radar radio frequency signal according to the interference wave gate and the detection result, and obtain the digital intermediate frequency interference signal after modulation; the digital-to-analog conversion module is used to convert the digital intermediate frequency interference signal into an analog intermediate frequency interference signal; The main control module is provided with a sorting module for sorting the PDW data to obtain the number of radars and the corresponding EDW data, wherein the EDW data includes the type, frequency, and repetition data of the radar signal, as well as the pulse width of the blind pulse and the main pulse of the early warning radar radio frequency signal; the gate generation module is used to generate a sampling gate, a window gate, a range gate, a transceiver gate, and an interference gate according to the detection signal and the EDW data; The microwave up-conversion module performs up-conversion processing on the analog intermediate frequency interference signal to obtain the radio frequency interference signal; A transmitting branch, used for transmitting the radio frequency interference signal; a transceiver antenna, shared by the receiving branch and the transmitting branch; A transceiver power amplifier module, used to control the switching of the receiving and transmitting states of the transceiver antenna according to the transceiver wave gate; The sampling gate, the window gate, the distance gate, the transceiver gate and the interference gate are obtained by the following steps: generating a sampling wave gate according to the detection signal; Generate a window gate according to the detection signal and EDW data, wherein the parameters of the window gate include window protection time t1, window time t2 and window interval time t3; The main control module sets the initial distance and the end distance according to the detection signal and the EDW data, and generates a distance gate in combination with the window gate; The main control module generates a transceiver gate for controlling the state switching of the transceiver antenna according to the detection signal, the window gate and the distance gate. The transceiver gate is in the receiving state when the detection signal exists, or the distance gate is at a low level, or the window gate is at a low level; the transceiver gate is in the transmitting state when the detection signal exists and the window gate and the distance gate are both at high levels.

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