7 results about "Frequency agility" patented technology

The application provides a multi-station frequency agile radar anti-interference and synergistic method, through two short baseline pulse interval frequency agile radars receiving echo signals and carrying out mixing processing and pulse compression; interference pulses of an echo data matrix are removed and the remaining pulses are combined to obtain a new echo data matrix; a distance-speed two-dimensional redundant dictionary matrix corresponding to the new echo data matrix and matched with target information is constructed in combination with transmission parameters; then a compressed sensing model is constructed and a reconstruction result of an original signal is obtained by solving.The application selects two pulse interval frequency agile radars to work synergistically, which can effectively improve signal processing gain, has strong electronic countermeasure capability, good target detection capability and excellent electromagnetic compatibility; by utilizing the characteristic that only some pulses of echo of the pulse interval frequency agile radar may be interfered, the interfered pulses are directly removed in the echo data matrix, and complex matrix operation is not involved, so that the calculation complexity is low and the running speed is fast.

A system and method for testing coherent and frequency agility characteristics of a radar echo simulation device, the system comprising: a local oscillator signal generation module for generating a frequency agile local oscillator signal; a signal transmission module for generating a modulated transmit baseband signal; upconverting the modulated signal and transmitting to the device under test, outputting the phase and frequency of the transmit baseband signal to a phase difference calculation module and a frequency difference calculation module; a signal reception module for receiving a signal returned by the device under test, downconverting the received signal based on the frequency agile local oscillator signal to obtain a receive baseband signal, outputting the phase and frequency of the receive baseband signal to the phase difference calculation module and the frequency difference calculation module; a phase difference calculation module for calculating the phase difference between the receive baseband signal and the transmit baseband signal; a frequency difference calculation module for calculating the frequency difference between the receive baseband signal and the transmit baseband signal; a testing module for determining the coherent characteristic and the frequency agility characteristic of the device under test based on a plurality of sets of phase difference values and a plurality of sets of frequency difference values, respectively.

The invention belongs to the field of radar signal processing, discloses a method for acquiring a one-dimensional range profile of a high-speed moving target by sub-pulse linear frequency modulation emission and inter-pulse frequency agility radar, and realizes frequency agility waveform echo high-speed target detection and correction based on sparse representation. In the prior art, distance and Doppler parameter estimation of target echoes can be generally realized by adopting sparse representation and sparse processing, and orthogonal matching pursuit (OMP) is one of common solution algorithms. The carrier frequency of a frequency agility radar jumps randomly between pulses, and the acquisition of a one-dimensional range profile of a high-speed moving target not only needs to correct inter-pulse range migration, but also needs to compensate intra-pulse range-Doppler coupling generated by the change of the carrier frequency. According to the method, firstly, compensation of intra-pulse distance-Doppler coupling is carried out, then distance migration correction is carried out on each frequency agility pulse based on a KeyStone method, sparse processing is carried out on a corrected echo signal by adopting an orthogonal matching pursuit algorithm, and a high-resolution one-dimensional distance image of a target is obtained. Experimental results show that the one-dimensional range profile processing method for performing inter-pulse range migration correction through the KeyStone algorithm is beneficial to target detection in high-speed motion.

The application provides a frequency-adjustable energy selection unit and surface, comprising a three-layer metal unit, a diode combination and a dielectric substrate design, realizes a working frequency agility function based on manual control through an applied bias voltage and an energy selection function controlled adaptively through sensing spatial energy, and has multiple functions of working frequency selection, working frequency band agility and spatial energy selection. The application solves the problem of unadjustable working frequency of the energy selection surface, so that the energy selection surface can not only realize strong electromagnetic protection, but also resist electronic interference, greatly expanding the function of the energy selection surface.

This invention discloses a radar timing processing method based on wide-speed coverage, belonging to the field of radar signal processing technology. It aims to solve the problems of poor clutter suppression, limited velocity measurement range, and severe range-folded clutter interference in complex clutter environments by traditional moving target indication (MTI) filters. This method achieves wide-speed coverage at three times the speed of sound and effectively suppresses range-folded clutter through a timing design that alternates between positive and negative frequency modulation slopes and uses carrier frequency agility, combined with a genetic algorithm-optimized staggered pulse repetition period (PRT) and MTI filter weight coefficients. Experimental results show that this method can reduce the average amplitude of folded clutter by approximately 45 dB, successfully separate target signals obscured by clutter, and significantly improve the radar's target detection performance in complex environments.

This invention provides a networked radar decision-making method based on an improved MADDPG, which balances resolution and anti-interference performance, and relates to the field of radar anti-interference technology. First, an adversarial scenario is constructed between the networked radar and a multi-point broadband frequency-sweeping jammer, signal distribution is analyzed, and overlap coefficients are established. Second, the radar cooperative scheduling process is modeled as a multi-agent partially observable Markov decision process, constructing a composite reward function that balances detection resolution and anti-interference performance. Then, a multi-agent deep deterministic policy gradient algorithm is used for network training, and a self-attention mechanism is introduced in the value evaluation to extract mutual interference topology features, obtaining the frequency agility strategy for each radar. This invention overcomes the limitations of traditional discrete frequency hopping, enabling the radar to adaptively utilize fragmented spectrum to elastically expand bandwidth under conditions of no online communication, effectively achieving a comprehensive improvement in high-precision detection and high anti-interference survivability.