Device for jamming synthetic aperture radar

Abstract

This application provides a device for jamming a synthetic aperture radar (SAR). The device includes: a receiving module for receiving a SAR signal; a processing module for modulating the SAR signal using a radio frequency multi-phase segmented modulation model to generate an interference signal for the SAR signal; and an output module for transmitting the generated interference signal to the SAR. This achieves low-cost SAR jamming.

Description

Technical Field

[0001] The present application relates to the field of radar countermeasure technology, and in particular to a device for interfering with synthetic aperture radar. Background Art

[0002] Currently, synthetic aperture radars (SARs) are carried on aerial and space platforms such as satellites, aircraft, and drones. They operate in multiple radio frequency bands, including L, X, C, Ku, Ka, and millimeter waves. They are capable of conducting long-range, high-resolution ground imaging and reconnaissance around the clock and in all weather conditions, acquiring intelligence information on ground targets. Existing jamming methods for SARs typically employ repeater jamming, with digital radio frequency memory (DRFM) serving as the core component.

[0003] In the process of implementing the prior art, the inventors found that:

[0004] As the performance of synthetic aperture radar systems continues to improve, the corresponding signal bandwidth continues to increase, requiring the digital processing capabilities of digital radio frequency memory (DRFM) to be enhanced in order to effectively jam synthetic aperture radar signals. However, the cost of using digital radio frequency memory (DRFM) and other frequency conversion components connected to it to jam synthetic aperture radar signals is relatively high.

[0005] Therefore, it is necessary to provide a low-cost technical solution for interfering with synthetic aperture radar. Summary of the Invention

[0006] The embodiments of the present application provide a low-cost technical solution for SAR jamming, which is used to solve the technical problem of high cost in the prior art for SAR jamming.

[0007] Specifically, a device for interfering with a synthetic aperture radar includes:

[0008] A receiving module, used for receiving synthetic aperture radar signals;

[0009] a processing module, configured to modulate the synthetic aperture radar signal using a radio frequency multi-phase segmented modulation model to generate an interference signal of the synthetic aperture radar signal;

[0010] The output module is used to send the interference signal of the generated synthetic aperture radar signal to the synthetic aperture radar.

[0011] Furthermore, the device for interfering with the synthetic aperture radar is also provided with a preprocessing module for preprocessing the synthetic aperture radar signal and determining a signal segment length value and a signal phase adjustment value for interfering with the synthetic aperture radar signal.

[0012] Furthermore, the radio frequency multi-phase segmented modulation model at least uses a radio frequency phase modulation device to perform multi-phase segmented modulation on the synthetic aperture radar signal.

[0013] Furthermore, the device for interfering with the synthetic aperture radar is also provided with a splitter for splitting the synthetic aperture radar signal.

[0014] Furthermore, the device for interfering with the synthetic aperture radar is also provided with a filter group for filtering the synthetic aperture radar signal.

[0015] Furthermore, the filtering of the synthetic aperture radar signal by the filter bank corresponds to the center frequency and bandwidth of the radio frequency phase modulation device.

[0016] Furthermore, the receiving module is also provided with a low-noise signal amplifying module for amplifying the received signal.

[0017] Furthermore, the receiving module is further provided with a detection unit for detecting whether it is a synthetic aperture radar signal.

[0018] The technical solutions provided in the embodiments of the present application have at least the following beneficial effects:

[0019] The device for interfering with synthetic aperture radar provided by the present application can replace the interference with synthetic aperture radar signals previously achieved through microwave radio frequency components such as digital radio frequency memory DRFM, up and down conversion, etc., and can simplify system design and reduce costs without reducing its core performance, while bringing the advantage of being able to process and interfere with SAR with a larger bandwidth. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0021] Figure 1 A schematic diagram of the structure of a device for interfering with synthetic aperture radar provided in an embodiment of the present application.

[0022] Figure 2 A schematic diagram of the structure of a device for interfering with synthetic aperture radar provided in an embodiment of the present application. DETAILED DESCRIPTION

[0023] To make the purpose, technical solutions, and advantages of this application more clear, the technical solutions of this application will be clearly and completely described below in conjunction with the specific embodiments of this application and the corresponding drawings. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0024] The present application is based on the principle that synthetic aperture radar obtains ground target intelligence through the two dimensions of distance and azimuth of the radar echo signal of the ground target, and provides a device for jamming synthetic aperture radar. At present, jamming of synthetic aperture radar signals is mainly achieved through microwave radio frequency components such as digital radio frequency memory DRFM and up and down frequency conversion. However, as the resolution index of synthetic aperture radar system continues to improve, the signal bandwidth required to jam synthetic aperture radar signals by using microwave radio frequency components such as digital radio frequency memory DRFM and up and down frequency conversion must be increased, which in turn leads to a corresponding increase in equipment cost. How to realize a low-cost device for jamming synthetic aperture radar is the technical problem that the technical solution of the present application aims to solve.

[0025] Synthetic Aperture Radar (SAR) is a high-resolution imaging radar that can produce high-resolution radar images similar to optical photography in extremely low visibility weather conditions. This radar utilizes the relative motion between the radar and the target to synthesize a smaller actual antenna aperture into a larger equivalent antenna aperture through data processing. This radar is also known as a synthetic aperture radar (SAR). SAR is characterized by high resolution, all-weather operation, and the ability to effectively detect camouflage and penetrate cover. The resulting high azimuth resolution is equivalent to that provided by a large-aperture antenna.

[0026] Radio Frequency (RF) stands for radio frequency, representing electromagnetic frequencies that can be radiated into space, ranging from 300 kHz to 30 GHz. RF, short for radio frequency, is a shorthand for high-frequency alternating electromagnetic waves. Alternating current that changes less than 1,000 times per second is considered low-frequency current, while current that changes more than 10,000 times per second is considered high-frequency current, and RF is one such high-frequency current.

[0027] The multi-phase segmented modulation described in this application is a two-dimensional processing of synthetic aperture radar (SAR) imaging, where the received signal is a pulse signal. When a pulse signal is received, the signal is segmented by time and phase modulated to generate an interference signal. After modulation, the generated interference signal can generate image overlays and surrounding background images in the SAR image, with controllable quantity, position, area, and brightness. It should also be noted that by setting the modulation parameter values in the multi-phase segmented modulation, the quantity, position, area, and surrounding background image generated in different SAR images can be obtained. It is understood that the RF multi-phase segmented modulation model is based on multi-phase segmented modulation and uses RF technology to implement the modulation of the image formed by the SAR signal.

[0028] Please refer to Figure 1 The present application provides a device for interfering with a synthetic aperture radar, comprising:

[0029] Receiving module 11, used for receiving synthetic aperture radar signals;

[0030] The processing module 12 is configured to modulate the synthetic aperture radar signal using a radio frequency multi-phase segmented modulation model to generate an interference signal of the synthetic aperture radar signal;

[0031] The output module 13 is configured to send the generated interference signal of the synthetic aperture radar signal to the synthetic aperture radar.

[0032] The receiving module 11 receives radiation source signals within a wide frequency range via a broadband antenna. It will be appreciated that the broadband antenna can receive radiation source signals within a wide frequency range, in addition to synthetic aperture radar signals, as well as other radiation source signals within the wide frequency range. A radiation source signal within a wide frequency range is a radiation source signal with a bandwidth greater than two octaves. The bandwidth ratio is the ratio of the highest frequency to the lowest frequency within the bandwidth.

[0033] In a preferred embodiment provided herein, the receiving module 11 may also include a signal detection unit for detecting synthetic aperture radar signals from radiation source signals within a wide frequency range received by the broadband antenna. Of course, the receiving module may also include a signal amplification unit to facilitate detection and identification of radiation source signals. It will be appreciated that the provision of a signal amplification unit and a signal detection unit enables the receiving module to more accurately receive synthetic aperture radar signals.

[0034] The processing module 12 is mainly used to process the synthetic aperture radar signal received by the receiving module 11 using a radio frequency multi-phase segmented modulation model. In the process of processing the synthetic aperture radar signal using a radio frequency multi-phase segmented modulation model, the processing module 12 does not need to perform up-conversion or down-conversion processing, and only needs to implement it through intermediate frequency processing. It can be understood that if the processing module 12 only needs to implement it through intermediate frequency processing, then the device for interfering with the synthetic aperture radar provided in this application needs to be equipped with a device to ensure that the bandwidth and frequency correspond when the processing module 12 is processing. In a preferred embodiment provided in this application, a device corresponding to the radio frequency multi-phase segmented modulation model in the processing module 12 can be set before or after the processing module of the device for interfering with the synthetic aperture radar, so that the processing module 12 processes the synthetic aperture radar signal and then generates an interference signal of the synthetic aperture radar signal.

[0035] The output module 13 transmits the generated interference signal to the synthetic aperture radar via a broadband transmitting antenna to the synthetic aperture radar. In a preferred embodiment provided herein, a signal amplification unit may also be provided in the output module 13 to ensure the quality of the interference signal of the output synthetic aperture radar signal.

[0036] Furthermore, in a preferred embodiment provided in the present application, the device for interfering with the synthetic aperture radar is further provided with a preprocessing module for preprocessing the synthetic aperture radar signal and determining interference parameters for interfering with the synthetic aperture radar signal.

[0037] Specifically, the device for jamming a synthetic aperture radar also includes a preprocessing module. This module is primarily used to analyze and process the SAR signal's radiator information and parameters. This analysis and processing determines the parameter values used to modulate the SAR signal. The parameter values used to modulate the SAR signal are the jamming parameters used to interfere with the SAR signal.

[0038] It can be understood that the parameter values of the modulated synthetic aperture radar signal determined by the pre-processing module are mainly used in the setting of the radio frequency multi-phase segmented modulation model parameters in the processing module. In a preferred embodiment provided by the present application, the parameter values of the modulated synthetic aperture radar signal determined by the pre-processing module are directly used in the setting of the radio frequency multi-phase segmented modulation model parameters of the processing module. Of course, the parameter values of the modulated synthetic aperture radar signal determined by the pre-processing module can also be used as reference values for the setting of the radio frequency multi-phase segmented modulation model parameters of the processing module. It should be pointed out that the specific relationship between the parameter values of the modulated synthetic aperture radar signal determined by the pre-processing module, i.e., the interference parameters of the interfering synthetic aperture radar signal, and the setting values of the radio frequency multi-phase segmented modulation model parameters of the processing module, obviously does not constitute a limitation on the specific protection scope of the present application.

[0039] It should be noted that the preprocessing module analyzes the SAR signal to obtain basic parameters of the SAR signal. Interference parameters that interfere with the SAR signal are determined based on the obtained basic parameters of the SAR signal. It should be noted that the RF multi-phase segmented modulation model in the processing module can modulate the SAR signal. However, the number of image blocks, image block positions, image block sizes, and image block brightness generated by the interference signal of the SAR signal generated by the processing module of the SAR signal require the setting of modulation parameter values of the RF multi-phase segmented modulation model. The modulation parameter values of the processing module can be determined by using or referencing the parameter values determined by the preprocessing module to modulate the SAR signal to determine the number of image blocks, image block positions, image block sizes, and image block brightness generated by the interference signal of the SAR signal. For example, after analyzing and processing the synthetic aperture radar signal, the preprocessing module determines a segment length value for modulating the synthetic aperture radar signal. Then, the processing module uses the segment length value for modulating the synthetic aperture radar signal determined in the preprocessing module to perform a radio frequency multi-phase segmented modulation model, and generates a synthetic aperture radar image block size determined by the signal segment length value.

[0040] It is understood that the preprocessing module 12 performs preprocessing on the SAR signal, not only to determine the signal segment length and signal phase adjustment value of the interfering SAR signal, but also to control the number of signal processing channels and signal delay. It is also understood that the modulation parameter values generated by the preprocessing module affect the number, size, position, and brightness of image blocks formed in the SAR by the interfering signal of the SAR signal after processing by the processing module 12, and are controlled by the modulation parameters of the preprocessing module.

[0041] Furthermore, in a preferred embodiment provided by the present application, the radio frequency multi-phase segmented modulation model at least uses a radio frequency phase modulation device to perform multi-phase segmented modulation on the synthetic aperture radar signal.

[0042] Specifically, the RF multi-phase segmented modulation model modulates the synthetic aperture radar signal using an RF phase modulation device. The RF phase modulation device can be a digitally controlled phase shifter or other device capable of performing RF phase modulation. In a preferred embodiment provided herein, the RF phase modulation device preferably employs a digitally controlled phase shifter. Furthermore, the RF phase modulation device employs at least two or more digitally controlled phase shifters.

[0043] It should be noted that implementing RF multi-phase segmented modulation using an RF phase modulation device requires consideration of the device's center frequency and bandwidth. Specifically, the device's instantaneous operating bandwidth cannot cover a wide operating frequency range. Therefore, before modulating the synthetic aperture radar signal, the RF phase modulation device must be configured to accommodate the frequency and bandwidth range it can receive. It is understood that a device enabling the RF phase modulation module to process synthetic aperture radar signals can be provided within or before the processing module. For example, a filter can be provided within or before the processing module to ensure normal operation of the RF phase modulation device.

[0044] Furthermore, in a preferred embodiment provided by the present application, the device for jamming a synthetic aperture radar is further provided with a splitter for splitting the synthetic aperture radar signal. The splitter is used to split the received synthetic aperture radar signal.

[0045] Specifically, the splitter can be provided within or before the processing module. After the synthetic aperture radar signal is split, it is modulated using the RF multi-phase modulation model. It is also understood that the device for jamming synthetic aperture radars can also include a combiner, which can be provided within or after the processing module. The combiner is primarily used to combine the jamming signal generated by the synthetic aperture radar signal after the synthetic aperture radar signal is modulated using the RF multi-phase segmented modulation model.

[0046] It should be noted that the arrangement of the splitter and combiner is made taking into account that the instantaneous operating bandwidth of the RF phase modulation device in the RF multi-phase segmented modulation model cannot cover a large operating frequency.

[0047] Furthermore, in a preferred embodiment provided in the present application, the device for interfering with the synthetic aperture radar is further provided with a filter group for filtering the synthetic aperture radar signal.

[0048] Specifically, the filter bank consists of at least two filters. The filter bank can be configured to divide the synthetic aperture radar signal into multiple channels. The center frequencies and bandwidths corresponding to the multiple channels correspond to the center frequencies and bandwidths of the RF phase modulation device. The center frequency refers to the filter passband frequency, and the bandwidth generally refers to the frequency bandwidth occupied by the signal.

[0049] It should be noted that the filter bank can also be provided within the processing module, or before or after the processing module, to filter the synthetic aperture radar signal before or after processing. After filtering, the synthetic aperture radar signal is modulated by a radio frequency phase modulation device corresponding to its center frequency and bandwidth. In a preferred embodiment provided by the present application, filter banks are provided before and after the processing module to filter the interference signal of the unprocessed synthetic aperture radar signal and the synthetic aperture radar signal processed by the processing module, respectively. This is to meet the processing conditions of the processing module and to generate an interference signal of the synthetic aperture radar signal that meets the filter requirements after processing by the processing module.

[0050] It is also understood that the device for interfering with a synthetic aperture radar may be equipped with a splitter, a combiner, and a filter. In a preferred embodiment provided in this application, the receiving module sends the received synthetic aperture radar signal to the splitter for branching, which is then divided into multiple channels by a filter bank. The center frequency and bandwidth of each channel correspond to the center frequency and bandwidth of the radio frequency phase modulation device. After being processed by the processing module, the signals are filtered again and then combined to generate an interference signal for the synthetic aperture radar signal.

[0051] Furthermore, in a preferred embodiment provided in the present application, the center frequency and bandwidth of the radio frequency phase modulation device are the same as the center frequency and bandwidth of the synthetic aperture radar signal.

[0052] Specifically, the RF phase modulation device primarily modulates the synthetic aperture radar signal through a digitally controlled RF phase shifter. It should be noted that since the instantaneous operating bandwidth of a digitally controlled RF phase shifter cannot cover a large operating frequency range, modulation of the synthetic aperture radar signal can be achieved by configuring splitters and filters. It should also be noted that the center frequency and bandwidth of the synthetic aperture radar signal channel achieved by configuring splitters and filters are identical to those of the digitally controlled RF phase shifter device. This enables the RF phase modulation device to modulate the synthetic aperture radar signal.

[0053] Furthermore, in a preferred embodiment provided in the present application, the receiving module is further provided with a low-noise signal amplifying module for amplifying the received signal.

[0054] Specifically, a low-noise signal amplification module is provided in the receiving module, which is mainly used to amplify the received radiation source signal to meet the subsequent interference with the synthetic aperture radar signal.

[0055] Furthermore, in a preferred embodiment provided in the present application, the receiving module is further provided with a detection unit for detecting whether it is a synthetic aperture radar signal.

[0056] Specifically, the detection unit detects the signal received by the receiving module to determine whether the signal is a synthetic aperture radar signal. In a preferred embodiment provided by the present application, the detection unit can be a reconnaissance receiver, which detects and determines whether the signal received by the receiving module is a synthetic aperture radar signal.

[0057] like Figure 2 As shown, a device for interfering with a synthetic aperture radar provided by the present application is provided. The receiving module 11 in the device for interfering with a synthetic aperture radar corresponds to the device for interfering with a synthetic aperture radar including: a broadband receiving antenna and a low-power amplifier LNA. The processing module 12 in the device for interfering with a synthetic aperture radar corresponds to the device for interfering with a synthetic aperture radar including: a splitter, a first filter group, a radio frequency phase modulation device, a second filter group, and a combiner. The output module 13 in the device for interfering with a synthetic aperture radar corresponds to the device for interfering with a synthetic aperture radar including: a power amplifier and a broadband transmitting antenna. The controller of the device for interfering with a synthetic aperture radar corresponds to the pre-processing module of the device for interfering with a synthetic aperture radar.

[0058] Specifically, the broadband receiving antenna receives the SAR signal, which is amplified by a low-power LNA amplifier and then transmitted to two channels. One channel passes through a splitter and a first filter to the RF phase modulation device, while the other channel enters the controller. The controller obtains the SAR signal's characteristic information and determines the parameters for modulating the SAR signal. The RF phase modulation device modulates the SAR signal based on the parameters determined by the controller. Before modulating the SAR signal, the RF phase modulation device processes the signal through the splitter and the first filter to align the center frequency and bandwidth of the SAR signal with those of the RF phase modulation device, thereby achieving modulation of the SAR signal. After modulating the SAR signal, the RF phase modulation device processes the signal through a second filter bank and a combiner to generate an interference signal for the SAR signal processed by the RF phase modulation device. Finally, the power amplifier amplifies the interference signal and transmits it through the broadband transmitting antenna.

[0059] The controller transmits the modulation values of the amplitude, frequency, and phase of the interfering SAR signal to the RF phase modulation device. The RF phase modulation device uses or references the modulation values sent by the controller to achieve different interference effects. The interference effect of the SAR signal is mainly reflected in the control of the interference image block, position, and size. For example, the size of the interference image block is controlled by the segment length of the SAR signal.

[0060] It should be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, product, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or includes elements inherent to such process, method, product, or apparatus. In the absence of further limitations, the phrase "comprises a..." to define an element does not preclude the presence of other identical elements in the process, method, product, or apparatus that includes the element.

[0061] The foregoing is merely an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should all be included within the scope of the claims of the present application.

Claims

1. A device for jamming synthetic aperture radar, characterized in that: include: A receiving module, used for receiving synthetic aperture radar signals; a processing module, configured to modulate the synthetic aperture radar signal using a radio frequency multi-phase segmented modulation model to generate an interference signal of the synthetic aperture radar signal; An output module, configured to send the generated interference signal of the synthetic aperture radar signal to the synthetic aperture radar; A splitter, used for splitting synthetic aperture radar signals; A combiner, configured to combine the interference signals; A filter bank for filtering synthetic aperture radar signals; The radio frequency multi-phase segmented modulation model at least uses a radio frequency phase modulation device to perform multi-phase segmented modulation on a synthetic aperture radar signal; The radio frequency phase modulation device adopts a digitally controlled phase shifter; The filtering of the synthetic aperture radar signal by the filter group corresponds to the center frequency and bandwidth of the radio frequency phase modulation device, and the filter group is composed of at least two filters; The receiving module sends the received synthetic aperture radar signal to the splitter for branching, and then divides it into multiple channels through the first filter group. The center frequency and bandwidth of each channel correspond to the center frequency and bandwidth of the radio frequency phase modulation device. After being processed by the radio frequency phase modulation device, it is filtered again through the second filter group and then combined to generate an interference signal of the synthetic aperture radar signal. The device for interfering with the synthetic aperture radar is further provided with a preprocessing module for preprocessing the synthetic aperture radar signal and determining interference parameters for interfering with the synthetic aperture radar signal; The receiving module is also provided with a detection unit for detecting whether it is a synthetic aperture radar signal.

2. The device for jamming synthetic aperture radar according to claim 1, wherein: The receiving module is also provided with a low-noise signal amplifying module for amplifying the received signal.

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