A distributed digital jammer dynamic sensitivity control method

Abstract

The application provides a distributed digital jammer dynamic sensitivity control method, which can perform multi-stage control on the receiving sensitivity of the digital jammer according to a multi-target jamming task, performs RF stage sensitivity control before a radio frequency signal enters a low noise amplifier, avoids signal saturation, performs sensitivity control at an intermediate frequency stage, judges the frequency coincidence of the intermediate frequency signal, performs dynamic attenuation on the coincident frequency band, and performs fixed attenuation on the non-coincident frequency band, performs digital stage sensitivity control on the signal after ADC sampling of the digital jammer, further reduces the receiving sensitivity of the digital jammer, and realizes the requirement of a large dynamic range of the digital jammer. In addition, in order to further reduce the influence of the multi-target jamming on the time sequence, a time fault-tolerant jammer control method is adopted, pulse stage control is adopted for the multi-target jamming task, the jammer is synchronously controlled to delay and hide according to the jamming wave gate output by the repetition frequency tracking, and the success rate of the multi-target jamming is improved.

Description

Technical Field

[0001] This application relates to the field of phased array technology, and in particular to a method for dynamic sensitivity control of a distributed digital interference source. Background Technology

[0002] In modern warfare, electronic warfare has become a crucial element of the battlefield. Radar is a vital tool for both sides to acquire battlefield information and maneuver weapons for attacks. Therefore, disrupting the enemy's radar system through electronic warfare disables their radar-dependent equipment. Consequently, in the face of increasingly complex electromagnetic environments, electronic warfare has become critical. To adapt to the demands of wideband, multi-target electronic warfare and improve the operational performance of jamming equipment, active jamming devices need to be able to continuously emit multiple jamming signals targeting different threats. When jamming equipment and reconnaissance / guidance equipment operate simultaneously, coupling effects inevitably occur between the antennas of the two devices. Therefore, if the power of the coupled signal to the receiving antenna exceeds the detection sensitivity, the jamming equipment will respond with interference, reducing its effectiveness against real threats.

[0003] With the development of phased array technology, active phased array jamming equipment has become an indispensable part of integrated radio frequency systems due to its advantages such as fast response, wide bandwidth, and multiple apertures. Active phased array jamming equipment receives target signals from reconnaissance and guidance equipment, which are then processed by a receiver and preprocessor to form reconnaissance parameters. Based on signal identification, the main processor determines the frequency, azimuth, and jamming pattern for different targets according to the type, operating mode, and threat level of the opposing radar. This generates corresponding jamming signals, which are allocated to different sub-apertures to form jamming beams, effectively interfering with the threatening targets. The jamming signal pattern control, jamming beam control, and jamming frequency modulation are formed by digital jamming sources under resource scheduling control.

[0004] Distributed digital jamming sources can reconstruct signals from multiple targets and precisely control the jamming waveform. However, due to the complexity of the task and the coupling effect of the reconnaissance jamming equipment, the coupling signal will enter the digital jamming source when the jamming signal is emitted, affecting the accuracy of the jamming waveform and thus reducing the jamming capability of the active jamming equipment. Summary of the Invention

[0005] This application provides a dynamic sensitivity control method for distributed digital interference sources, which can be used to solve the technical problem of interference to active interference equipment. This application can perform multi-level sensitivity control for multi-target interference tasks, achieve transmit / receive isolation of multi-aperture distributed interference sources on the array, and simultaneously complete time-tolerant distributed interference source synchronization control based on multi-target interference tasks.

[0006] This application provides a method for dynamic sensitivity control of a distributed digital interference source, the method comprising:

[0007] Step 1: Perform radio frequency level sensitivity control on the radio frequency signals used for reconnaissance guidance;

[0008] Step 2: Down-convert the radio frequency signal to obtain the intermediate frequency signal;

[0009] Step 3: Perform intermediate frequency sensitivity control;

[0010] Step 4: Perform ADC sampling processing on the signal after intermediate frequency sensitivity control to obtain a digital signal;

[0011] Step 5: Perform digital sensitivity control on the sampled signal;

[0012] Step 6: The repetition rate tracking control performs matched filtering based on parameters including RF, DOA, and PW, filtering out PDW values ​​outside the set range. Based on the time-domain correlation characteristics of radar pulse signals, time-domain correlation processing is performed using a variable delay line and the filtered output pulse signal stream to establish tracking of threat targets and generate corresponding interference timing for the threat targets.

[0013] Step 7: Send the interference gate to the synchronization control, perform time-tolerable processing based on the interference gate of the multi-target interference task, and output the delayed stealth enable signal.

[0014] Step 8: Perform interference modulation on the sampled attenuated digital signal according to the interference gate and the masking enable signal;

[0015] Step 9: Perform DAC processing on the modulated signal to restore the digital signal to the baseband radio frequency signal.

[0016] Further, step 1 involves performing radio frequency level sensitivity control on the reconnaissance-guided radio frequency signal; including:

[0017] The RF power automatic adjustment link dynamically controls the amplitude of the RF signal to ensure controllable RF sensitivity of the system. The RF signal detected by the antenna is subjected to a first-stage amplitude limiting filter amplification to ensure that the link is not saturated and to prevent interference signals from burning through the link, resulting in the primary signal S0. Then, the power of the signal is controlled by a digitally controlled attenuator. The intermediate signal S1 after digital control attenuation is amplified by a second stage of low noise to obtain the final signal S2. At the same time, the final signal S2 is controlled by a coupling branch. When the final signal S2 does not meet the system power requirements, the digitally controlled attenuator is controlled to dynamically control the signal amplitude to prevent signal saturation. The low-noise amplified signal S2 is then sent to the downconversion module.

[0018] Further, step 3 involves controlling the intermediate frequency sensitivity; including:

[0019] Frequency overlap determination is performed on the intermediate frequency signal and the guiding intermediate frequency signal. When the intermediate frequency f of the task guidance is different from the intermediate frequency f of other tasks, the frequency overlap determination is performed. i When they do not overlap, the corresponding intermediate frequency signal is attenuated by a fixed attenuation G1; if the intermediate frequency f is different from the intermediate frequency f guided by other tasks... i If there are overlapping frequency bands, the overlapping frequency bands will be dynamically attenuated to a greater extent, and the attenuation will be increased by ΔG on the basis of the fixed attenuation G1.

[0020] Further, step 5 involves digitally controlling the sensitivity of the sampled signal; including:

[0021] Digital channelization is used to filter the digital signal input to the front-end broadband sampling, dividing the broadband signal into several sub-frequency band components; channelization reception divides the radio frequency signal into sub-channels, processing the broadband data into multi-channel narrowband sub-channel data; channelization transmission processes the modulated signal, recovers the broadband sampling signal after channel synthesis, and outputs it.

[0022] The significant advantages of this invention compared to existing technologies are:

[0023] (1) By adopting a multi-level sensitivity control strategy, the impact of multiple interference tasks on the transmission and reception of distributed digital interference sources is comprehensively considered. Multi-level sensitivity control is designed in the link, which can realize the transmission and reception isolation between distributed digital interference sources while multiple target interference tasks are executed, thereby improving the interference effectiveness of active phased array interference equipment.

[0024] (2) A time-tolerant interference source control method is adopted. When multiple targets are interfered with, a pulse-level task control method is adopted. According to the interference gate output by the repetition frequency tracking, other interference sources are synchronously controlled to delay and hide, thereby reducing the mutual influence of interference tasks in the timing and improving the success rate of multi-target interference. Attached Figure Description

[0025] Figure 1 A schematic diagram of a reconnaissance-guided jamming system provided in an embodiment of this application;

[0026] Figure 2 This is a flowchart of radio frequency stage sensitivity control provided in an embodiment of this application;

[0027] Figure 3 This is a downconversion branch diagram provided in an embodiment of this application;

[0028] Figure 4 The tracking control flowchart provided in the embodiments of this application;

[0029] Figure 5 A flowchart illustrating the dynamic sensitivity control of a digital interference source provided in an embodiment of this application. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0031] The methods provided in this application include:

[0032] 1. Multi-level sensitivity control.

[0033] Multi-level sensitivity control methods primarily involve controlling the receiving sensitivity of digital jamming sources at multiple levels based on the multi-target jamming mission, thereby achieving transmit / receive isolation of distributed digital jamming sources across different apertures. Multi-level sensitivity control is divided into radio frequency (RF) level, intermediate frequency (IF) level, and digital level, with the receiving sensitivity of the digital jamming sources controlled according to the transmit power levels of the jamming mission.

[0034] RF Sensitivity Control: When active phased array jamming equipment performs multi-target jamming, excessive transmit power may saturate the signal entering the low-noise amplifier, leading to signal distortion and affecting the jamming effect. Therefore, the link is automatically adjusted using RF power, and the amplitude of the RF signal is dynamically controlled to ensure controllable RF sensitivity of the system. The RF signal detected by the antenna is subjected to a first-stage amplitude limiting filter amplification to ensure that the link is not saturated and to prevent the interference signal from burning through the link, resulting in signal S0. Then, the power of the signal is controlled by a digitally controlled attenuator. The digitally attenuated signal S1 is then subjected to a second-stage low-noise amplification to obtain signal S2. At the same time, signal S2 is controlled by a coupling branch. When signal S2 does not meet the system power requirements, the digitally controlled attenuator is dynamically controlled to prevent signal saturation. The low-noise amplified signal S2 is then sent to the down-conversion module.

[0035] Intermediate Frequency (IF) Sensitivity Control: IF sensitivity control is performed before the digital interference source's ADC sampling. This is to address two main concerns: firstly, excessive interference source signal storage could lead to ADC saturation; secondly, it's crucial to consider whether the frequency band emitting interference will affect the reception of another aperture. In other words, when the interference tasks of two apertures overlap in frequency bands, the interference emitted by each aperture will inevitably affect the stored frequency of the digital interference source. Therefore, when the interference task frequency bands overlap, IF sensitivity control is implemented to attenuate the IF signal sampled by the ADC, achieving transmit / receive isolation from interference within the same frequency band of the digital interference source.

[0036]

[0037] As shown in formula (2), frequency overlap judgment is performed on the intermediate frequency signal of the guidance. When the intermediate frequency f of the task guidance is different from the intermediate frequency f of other tasks guidance... i When they do not overlap, the intermediate frequency signal is attenuated by a fixed G1; if the intermediate frequency f is different from the intermediate frequency f guided by other tasks... iIf there are overlapping frequency bands, the overlapping frequency bands will be dynamically attenuated to a greater extent. The attenuation will be increased by ΔG on the basis of fixed attenuation G1 to reduce the transmission and reception impact between interference sources.

[0038] Digital-level sensitivity control: Digital-level sensitivity control is performed in the digital domain after sampling by the digital interference source's ADC. Intermediate-frequency (IF) level sensitivity control typically has a maximum dynamic range of 20-30 dB, which is insufficient to meet the isolation requirements of high-power interference sources. Therefore, power control of the sampled signal is necessary. This involves increasing attenuation in the digital domain, i.e., reducing the power value of the sampled signal, to further reduce the impact of transmitted interference and meet the large dynamic range requirement of digital interference source reception. Digital channelization filters the broadband sampled input digital signal, dividing it into several sub-frequency band components. Channelized reception divides the RF signal into sub-channels, processing the broadband data as multi-channel narrowband sub-channel data. Channelization reduces the data processing rate while improving the signal-to-noise ratio, which is beneficial for interference modulation. Channelized transmission processes the modulated signal, recovers the broadband sampled signal after channel synthesis, and outputs it.

[0039] 2. Time-tolerant distributed interference source synchronization control.

[0040] Synchronization control of distributed jamming sources based on time-tolerance primarily considers the impact between the transmission and reception of digital jamming sources in the time domain. At the instant of jamming transmission, there is a step at the pulse leading edge, resulting in complex spectral components that affect the reception of other digital jamming sources. Therefore, time-tolerance processing is performed in the time domain. For multi-target jamming, a pulse-level task control method is adopted. Based on the jamming gate output by tracking the repetition rate, if a digital jamming source transmits jamming at time t1, then the synchronization control of other jamming sources will perform concealment within the time interval t1+Δt, reducing the impact of the spectral components generated by the jamming source at time t1 on other digital jamming sources, reducing the temporal coupling effect of the jamming task, and improving the success rate of multi-target jamming.

[0041] Referring to the accompanying drawings, this invention provides a dynamic sensitivity control method for distributed digital jamming sources. This application utilizes a multi-level sensitivity control method to achieve transmit / receive isolation of multi-aperture distributed jamming sources on an array and a time-tolerant distributed jamming source synchronization control method. The block diagram of the reconnaissance-guided jamming system is shown below. Figure 1 As shown, the reconnaissance receiving antenna receives external signals. After processing, the reconnaissance guidance equipment sends the radio frequency signal of the jamming target to the active phased array jamming equipment. The control module of the active phased array jamming equipment completes the multi-target jamming task with multiple apertures on the array surface through a distributed digital jamming source. The jamming signal emitted by the transmitting aperture is coupled to the reconnaissance receiving antenna. The coupled signal enters the digital jamming source through the link, thus affecting the jamming signal modulated by the digital jamming source, and ultimately affecting the success rate of multi-target jamming of the active phased array jamming equipment.

[0042] A flowchart of a method for dynamic sensitivity control of a distributed digital interference source is shown below. Figure 3 As shown, it includes the following steps:

[0043] Step 1: Perform radio frequency level sensitivity control on the reconnaissance-guided radio frequency signal. The flowchart is as follows: Figure 2 As shown, when an active phased array jamming device performs multi-target jamming, if the transmit power of the jamming target is too high, it may saturate the signal entering the low-noise amplifier, leading to signal distortion and affecting the jamming effect. Therefore, this invention designs an automatic RF power adjustment link to dynamically control the amplitude of the RF signal to ensure that the system's RF sensitivity is controllable. The RF signal detected by the antenna is subjected to a first-stage amplitude limiting filter amplification to ensure that the link is not saturated and to prevent the interference signal from burning through the link, resulting in a primary signal S0. Then, the power of the signal is controlled by a digitally controlled attenuator. The intermediate signal S1 after digitally controlled attenuation is amplified by a second stage to obtain the final signal S2. At the same time, the final signal S2 is controlled by a coupling branch. When the final signal S2 does not meet the system power requirements, the digitally controlled attenuator is controlled to dynamically control the signal amplitude to prevent signal saturation. The low-noise amplified signal S2 is then sent to the down-conversion module.

[0044] Step 2: Down-convert the radio frequency signal to obtain the intermediate frequency signal. The down-conversion branch is as follows: Figure 3 As shown.

[0045] Step 3: Perform frequency overlap judgment on the intermediate frequency signal. Perform frequency overlap judgment on the guided intermediate frequency signal. When the guided intermediate frequency f of the task matches the guided intermediate frequency f of another task... i When they do not overlap, the corresponding intermediate frequency signal is attenuated by a fixed attenuation G1; if the intermediate frequency f is different from the intermediate frequency f guided by other tasks... i If there are overlapping frequency bands, the overlapping frequency bands will be dynamically attenuated to a greater extent, and the attenuation will be increased by ΔG on the basis of the fixed attenuation G1.

[0046] Assuming the interference frequency band for Task 1 is 9GHz to 10GHz and the interference frequency band for Task 2 is 9.5GHz to 10.5GHz, then in Task 1, the attenuation is 20dB for the 9GHz to 9.5GHz band and 30dB for the 9.5GHz to 10GHz band, resulting in an additional 10dB attenuation. Task 2 undergoes the same treatment: 30dB attenuation for the 9.5GHz to 10GHz band and 20dB attenuation for the 10GHz to 10.5GHz band.

[0047] Step 4: Perform ADC sampling processing on the signal after intermediate frequency sensitivity control to obtain a digital signal;

[0048] Step 5 involves digital sensitivity control of the sampled signal. Digital channelization primarily involves filtering the broadband input digital signal from the front end, dividing the broadband signal into several sub-frequency band components. Channelized reception divides the RF signal into sub-channels, processing the broadband data as multi-channel narrowband sub-channel data. Channelization reduces the data processing rate while improving the signal-to-noise ratio, which is beneficial for interference modulation. Channelized transmission processes the modulated signal, recovers the broadband sampled signal after channel synthesis, and outputs it. Adding attenuation in the digital domain reduces the power value of the sampled signal.

[0049] Step 6: The repetition rate tracking control performs matched filtering based on parameters including RF, DOA, and PW, filtering out PDW values ​​outside the setpoint. Based on the time-domain correlation characteristics of radar pulse signals, time-domain correlation processing is performed using a variable delay line and the filtered output pulse signal stream to establish tracking of the threat target. Correlation is then applied to the threat target, generating corresponding interference timing and feeding back the tracking status to the synchronization control. Figure 4 As shown.

[0050] Step 7: Send the interference gate to the synchronization control, perform time-tolerable processing based on the interference gate of the multi-target interference task, and output a delayed stealth enable signal.

[0051] Step 8: Perform interference modulation on the sampled and attenuated digital signal based on information such as the interference gate and the masking enable signal;

[0052] Step 9: Perform DAC processing on the modulated signal to recover the baseband RF signal from the digital signal.

[0053] This application employs a multi-level sensitivity control method and a time-tolerant distributed jamming source synchronization control method to achieve transmit / receive isolation during multi-target jamming using a multi-aperture distributed jamming source on an array. The receiving sensitivity of the digital jamming source is controlled at multiple levels according to the multi-target jamming task, with analog and digital domain sensitivity control achieved at the radio frequency, intermediate frequency, and digital levels. A pulse-level task control method is used to synchronously control the jamming source for delayed concealment based on the jamming gate output by tracking the repetition rate, reducing the timing coupling effect of the jamming task and improving the success rate of multi-target jamming.

[0054] The embodiments described above do not constitute a limitation on the scope of protection of this application.

Claims

1. A method for dynamic sensitivity control of a distributed digital interference source, characterized in that, The method includes: Step 1: Perform radio frequency level sensitivity control on the radio frequency signals used for reconnaissance guidance; Step 2: Down-convert the radio frequency signal to obtain the intermediate frequency signal; Step 3: Perform intermediate frequency sensitivity control; Step 4: Perform ADC sampling processing on the signal after intermediate frequency sensitivity control to obtain a digital signal; Step 5: Perform digital sensitivity control on the sampled signal; Step 6: The repetition rate tracking control performs matched filtering based on parameters including RF, DOA, and PW, filtering out PDW values ​​other than the set values; based on the time-domain correlation characteristics of the radar pulse signal, the variable delay line and the filtered output pulse signal stream are used for time-domain correlation processing to establish tracking of the threat target and generate corresponding interference timing for the threat target. Step 7: Send the interference gate to the synchronization control, perform time-tolerable processing based on the interference gate of the multi-target interference task, and output the delayed stealth enable signal. Step 8: Perform interference modulation on the sampled attenuated digital signal according to the interference gate and the masking enable signal; Step 9: Perform DAC processing on the modulated signal to restore the digital signal to the baseband radio frequency signal.

2. The method according to claim 1, characterized in that, Step 1, perform radio frequency level sensitivity control on the reconnaissance-guided radio frequency signal; including: The RF power automatic adjustment link dynamically controls the amplitude of the RF signal to ensure controllable RF sensitivity of the system; the RF signal detected by the antenna undergoes a first-stage amplitude limiting filter amplification to ensure that the link does not saturate, while preventing interference signals from burning through the link, thus obtaining the primary signal. Then, the power of the signal is controlled by a digitally controlled attenuator to attenuate the intermediate signal. Two-stage low-noise amplification is performed to obtain the final signal. Simultaneously, the final signal is coupled through the coupling branch. Control is implemented when the final signal is received. When the system power requirements are not met, the digitally controlled attenuator dynamically controls the signal amplitude to prevent signal saturation; the signal after low-noise amplification... It is sent to the downconverter module.

3. The method according to claim 1, characterized in that, Step 3, perform intermediate frequency sensitivity control; including: Frequency overlap determination is performed on the intermediate frequency signal, and frequency overlap determination is performed on the guided intermediate frequency signal. When the intermediate frequency of the task guidance... Mid-frequency of other task-guided When they do not overlap, the corresponding intermediate frequency signal is attenuated at a fixed rate. If it is mid-frequency Mid-frequency of other task-guided If there are overlapping frequency bands, then the overlapping frequency bands will be subject to greater dynamic attenuation, while the fixed attenuation will be applied. Add on the basis The attenuation.

4. The method according to claim 1, characterized in that, Step 5, perform digital sensitivity control on the sampled signal; including: Digital channelization is used to filter the digital signal input to the front-end broadband sampling, dividing the broadband signal into several sub-frequency band components; channelization reception divides the radio frequency signal into sub-channels, processing the broadband data into multi-channel narrowband sub-channel data; channelization transmission processes the modulated signal, recovers the broadband sampling signal after channel synthesis, and outputs it.

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