15 results about "Radar frequency" patented technology

The invention relates to the technical field of underground space detection, and discloses a high-resolution three-dimensional imaging GNSS (Global Navigation Satellite System) positioning type shallow cavity detection system which comprises a mobile carrier platform, a step frequency continuous wave radar subsystem, a high-precision positioning and attitude sensing subsystem, a central control and edge calculation subsystem and a wireless communication module. According to the system, radar acquisition and hardware-level synchronization of positioning data are realized by using GNSS pulse per second; the central control subsystem dynamically modulates the radar frequency step number and the residence time according to the instantaneous velocity of the carrier to ensure that the space sampling interval is constant; and signal enhancement is carried out in combination with geographic semantic prior, three-dimensional deduction reconstruction is carried out on sparse survey line data by using a conditional generative adversarial network, and active supplementary collection of a reverse-driven low-confidence region is evaluated through confidence. According to the method, high-precision positioning, self-adaptive efficient acquisition and full-process closed-loop detection of the underground cavity are realized, and the reliability of detection data and the engineering application value are improved.

A wireless device is configured to transmit radar signals at extremely low spectral density so that the receiver can be operated at the same time without saturating and thereby enabling full-duplex operation. To achieve sufficient range, beamforming is used together with a very long correlation time for detection of the radar signal, in which case the receiver can resolve backscattered or reflected radar signals far below the noise floor, while the bandwidth of the transmitted radar signal can be very high. The wide bandwidth enables the wireless device to maintain a low power spectral density while increasing output power, and also increase the depth resolution. The extremely low power spectral density even in the transmission beam direction makes the probability that communication will be disturbed very low. The high bandwidth calls for digital filters for both transmitted and received signals to equalize the radar frequency response characteristics of the radio unit.

The invention particularly relates to a complex modulation signal generation method based on multiphase fitting modeling, belongs to the field of radars, and is applied to a radar frequency synthesizer. The method comprises the following steps: by taking an FPGA (Field Programmable Gate Array) and a DAC (Digital-to-Analog Converter) as core hardware, generating an n-phase phase increment sequence through multi-phase fitting modeling according to the phase change characteristics of CW, LFM and NLFM signals and the phase-to-amplitude conversion IP instantiation number of the FPGA; amplitude codes are output through multiple paths of IPs, and after cross sorting is carried out according to the phase relation, the amplitude codes are transmitted to a DAC through an LVDS or JESD204B / C high-speed interface to generate a target signal. According to the method, signal phase characteristics are fitted in a targeted manner, phase increment can be calculated in real time through LFM signal generation, storage is not occupied additionally, the three types of signals are consistent in processing flow, high in universality and easy to transplant, and high-stability and high-precision complex modulation signals can be generated efficiently.

This invention relates to a method for generating frequency-agile radar signals, belonging to the field of radar frequency-hopping signal technology. The invention includes S1, quantizing an initial chaotic sequence into an integer chaotic sequence; and S2, determining the optimal control parameter u of the integer chaotic sequence using a simulated annealing algorithm. b S3, Generate the target chaotic sequence; S4, Construct the first frequency-agile radar sequence based on the target chaotic sequence; S5, Establish the data training set Ψ; S6, Train the CNN network model using the data training set Ψ, and use the CNN network to identify the given chaotic sequence and find the optimal threshold λ. k S6, perform binary quantization on the given chaotic sequence to determine the second frequency-agile radar sequence; S7, construct the target frequency-agile radar sequence. This invention utilizes two optimization methods—simulated annealing and convolutional neural networks—to enhance the randomness of the target frequency-agile radar sequence, enabling it to solve the problems of traditional radar systems, such as the ease of signal detection and interception, and susceptibility to interference.

The disclosure relates to the field of radar sensors, particularly to radar sensors for radar sensing using wireless communication signals. The method includes: receiving a reflected communication signal, wherein the reflected communication signal is a sent communication signal that is reflected by at least one object. The frequency of the sent communication signal is within a radar frequency range, and the sent communication signal includes a sent data payload, and the reflected communication signal includes a corresponding reflected data payload. The reflected data payload is compared with the sent data payload, resulting in a compared data payload; and a delay information and / or a velocity information of the at least one object is extracted from the compared data payload.

The invention discloses a frequency hopping radar deception jamming optimization method based on a four-dimensional antenna array, which aims at solving the problem of jamming failure caused by a wave beam squint effect when the existing four-dimensional antenna array faces a broadband radar with fast frequency hopping, and comprises the following steps of: constructing a broadband array directional diagram model taking a whole radar frequency hopping frequency point set as a variable; and a layered optimization cost function is constructed. The function preferentially ensures that the echo in the true target direction is suppressed to be below a safety threshold in a full frequency band, and then the minimum gain in the false target direction is maximized. And performing global optimization on radio frequency switch time sequence parameters of each unit of the array by adopting a differential evolution algorithm to obtain a group of robust optimal time sequences irrelevant to frequency. The time sequence at the moment is loaded to the controller, so that the four-dimensional antenna array can stably realize the deception jamming effect of true target stealth and false target enhancement in the whole frequency hopping bandwidth of the radar without real-time adjustment, the aperture transition effect is effectively overcome, and the jamming robustness during frequency change of enemy radar is ensured.

The utility model relates to the technical field of wave-absorbing materials, in particular to a wave-absorbing material with a multistage laminated cavity, which comprises a first wave-absorbing layer, a second wave-absorbing layer fixedly mounted at the lower end of the first wave-absorbing layer, and a third wave-absorbing layer fixedly mounted at the lower end of the second wave-absorbing layer. The first wave absorbing layer comprises a first wave absorbing plate and a first wave absorbing cavity formed in the front side surface of the first wave absorbing plate. According to the utility model, through the three wave absorbing layers, high-efficiency absorption of electromagnetic waves can be realized in a wide frequency range, application requirements of different frequency bands, such as from a low-frequency communication frequency band to a high-frequency radar frequency band, can be met, the multi-stage laminated cavity structure enables the electromagnetic waves to be reflected and absorbed for multiple times in the material, and the electromagnetic wave absorption efficiency is improved. The absorption efficiency of electromagnetic wave energy is greatly improved, and the intensity of reflected waves can be effectively reduced.

The application discloses an external radiation source radar frequency domain sliding expansion cancellation method and belongs to the field of digital signal processing. The application realizes the method as follows: overlapping segmentation is performed on a monitoring signal and a reference signal, and fast Fourier transform is performed; the strong correlation between the reference signal and multipath clutter at the same frequency point is utilized to suppress the static clutter at each frequency point in the bandwidth; the frequency domain signal after the static clutter suppression is transformed to the time domain, the overlapping part is removed, and the complete time domain signal after the clutter suppression is obtained; distance-Doppler two-dimensional matched filtering is performed, and moving clutter interference is detected, the moving clutter with different Doppler shifts is suppressed step by step, the filter order is always one order, the operation amount of the algorithm is significantly reduced, and the memory occupation is reduced. The application utilizes the principle of the external radiation source radar signal, can effectively suppress the interference of the moving clutter and the static clutter, is more easy to realize real-time processing of the signal, is not limited to the radiation source signal with a specific structure, and is more universal.

The invention discloses a software and hardware design method of a radar frequency agility control system based on an RFSoC, and the method employs a ZYNQ chip and a radio frequency front-end receiving and transmitting assembly to carry out the design of a radar system, and employs an upper computer to carry out the control and transmission of frequency agility parameters. Waveform generation is carried out through a ZYNQ chip, AD / DA conversion is carried out, frequency agility control is carried out through a control radio frequency front-end transceiving assembly, and rapid response to interference changes can be realized through efficient processing and real-time control. According to the RFSoC-based radar frequency agility control system digital signal processing platform, radar waveform generation and inter-frame agility, inter-pulse agility and shield agility of radio frequency can be realized according to radar application scene requirements.

This invention discloses an optimized method for deception jamming of frequency-hopping radar based on a four-dimensional antenna array. This method addresses the problem of existing four-dimensional antenna arrays failing to jam against broadband radars with rapidly changing frequencies due to beam squint effects. It constructs a broadband array pattern model with the entire radar frequency hopping point set as variables and establishes a hierarchical optimization cost function. This function prioritizes suppressing the echo from the true target direction to below a safe threshold across the entire frequency band, and then maximizes the minimum gain in the direction of the false target. A differential evolution algorithm is used to globally optimize the RF switching timing parameters of each array element, obtaining a set of frequency-independent robust optimal timing sequences. Loading these timing sequences into the controller enables the four-dimensional antenna array to stably achieve deception jamming effects that conceal the true target and enhance the false target across the entire frequency hopping bandwidth of the radar without real-time adjustments. This effectively overcomes the aperture crossing effect and ensures the robustness of jamming when the enemy radar frequency changes.

The invention discloses an underground pipeline detection method and system based on motor vehicle traction. The method comprises the following steps: step 1, collecting vehicle state multi-physics field joint signals and preprocessing the signals to generate a standardized sequence; step 2, inputting the potential vector sequence, the vehicle speed and the attitude into a multi-physics field controllable Kupman self-encoding network, and outputting a potential vector sequence; 3, linear propagation is executed to calculate a trigger interval correction value; 4, adjusting the radar frequency and the electromagnetic phase according to the correction value, collecting a new signal, and calculating a residual error; 5, when the residual exceeds the threshold value, updating the propagation and control matrix and adjusting the vehicle speed and the chassis height; step 6, iterating the above process until residual convergence, and obtaining an aligned signal sequence; and 7, inputting an identification operator to generate an underground pipeline three-dimensional center line model, and outputting a detection result. According to the invention, high-precision alignment of multi-physical field signals and accurate detection of three-dimensional modeling of underground pipelines are realized.

A method for controlling radar frequency hopping includes determining start frequencies of a plurality of frequency modulated continuous wave (FMCWs) based on a first function, and controlling a radar to sequentially transmit the plurality of FMCWs by performing frequency hopping based on the determined start frequencies.

This application relates to the field of antenna technology, providing a bidirectional millimeter-wave radar antenna, including a dielectric substrate and antenna elements respectively disposed on both sides of the dielectric substrate. Each antenna element includes a waveguide cavity and a waveguide cover disposed on the waveguide cavity. The waveguide cavity has multiple square openings, the waveguide cover has multiple slots, and multiple coplanar waveguide microstrip lines are disposed on both sides of the dielectric substrate. The coplanar waveguide microstrip lines connect to the square openings, and the other side of each square opening connects to the slots. In practical applications, the antenna elements of the bidirectional millimeter-wave radar antenna employ a waveguide slot array configuration, achieving broadband coverage of 77GHz-81GHz, including both 77GHz and 79GHz detection radar frequency bands. This enables high-precision radiation detection, strong radar antenna compatibility, and a wide channel coverage angle. Furthermore, the bidirectional millimeter-wave radar antenna's antenna elements achieve bidirectional radiation through a double-sided configuration, realizing a 360° radiation coverage range.

The application belongs to the technical field of radar target recognition, and particularly relates to a radar frequency band fusion expansion method based on MP and Root-MUSIC algorithm. The method comprises the following steps: step 1: setting two adjacent radars, the observation angles of which are the same, and the working frequencies of which are different, so that a full-polarization GTD model of low-frequency and high-frequency electromagnetic echo is established for a stationary target composed of scattering centers; step 2: using echo data and conjugate data, incoherent parameters, i.e. linear phase and fixed phase, are estimated; step 3: using an improved algorithm to process coherent data, poles and amplitudes of a wideband full-polarization model are estimated, and then original data of low-frequency subband and high-frequency subband are used to calculate a fusion signal of a full frequency band. The multi-frequency band fusion method provided by the application uses original data and a conjugate form to construct a new covariance matrix, so that the modified algorithm has better parameter estimation performance under the same signal-to-noise ratio.

This invention provides a split-type multi-frequency reconfigurable 3D radar detection system and method. Multiple independently frequency-selectable antenna array modules are flexibly reconfigured through a standardized combination interface. Combined with a distributed main control module, inter-module collaborative control and data fusion are achieved, constructing a modular detection architecture with configurable frequencies, variable form, and adjustable deployment. This architecture supports switching between various operating modes, such as single-module handheld fine detection and multi-module vehicle-mounted rapid survey. A multi-axis robotic arm precisely adjusts the relative positions and detection angles of the modules, ensuring spatiotemporal synchronization and consistency of multi-frequency data. Combined with high-precision positioning and 3D reconstruction algorithms, high-precision 3D images of underground targets are generated. This invention overcomes the limitations of traditional radar frequency fixation and structural rigidity, balancing detection depth and resolution, and significantly improving equipment portability, scalability, and environmental adaptability.