4results about How to "High imaging performance" patented technology

The invention discloses a multi-view MIMO radar correlated imaging radiation field design method based on image entropy, which considers the fluctuation of the scattering intensity of each resolution unit of a target in an imaging scene under a multi-view condition, carries out statistical modeling on the scattering intensity of each resolution unit of the target, and starts from the whole process of transmitting, receiving and processing a signal. By constraining the condition number of a radiation field Gram matrix and the image entropy of imaging and through continuous iterative optimization, an array type of an MIMO radar transmitting waveform and a transmitting array which have a good suppression effect on target grid energy dissipation and are stable in imaging is found, and the correlation between a radiation field reference matrix and signal echoes is improved. According to the method, radar correlated imaging can be carried out on the target with fluctuating scattering intensity of each resolution unit by using the optimized emission signal waveform and the array of the emission array, the randomness of a radiation field is enhanced, the energy dissipation degree of a target grid is reduced, the imaging error is reduced, and a better radar imaging result can be obtained.

The embodiment of the present disclosure discloses a flexible combined multifunctional broadband metasurface antenna for synthetic aperture radar, which comprises, from inside to outside, a core metasurface antenna located at the center and a peripheral metasurface located at the periphery, and the core metasurface antenna and the peripheral metasurface are connected through a U-shaped slot plug structure, wherein the core metasurface antenna and the peripheral metasurface can be replaced according to different application scenarios. The present disclosure has the characteristics of simple and reliable modular structure and flexible configuration according to task requirements; it meets the requirements of high-precision multiple transmission modes and corresponding amplitude-phase consistent multiple polarization reception of synthetic aperture radar, effectively increases the working bandwidth of the core antenna under low profile, reduces the radar scattering area of the antenna, optimizes the antenna radiation pattern and reduces the mutual coupling characteristics, further improves the imaging performance of the synthetic aperture radar, and reduces the signal-to-interference ratio of the synthetic aperture radar system.

This invention belongs to the field of biomedical materials technology, and relates to a signal probe that simultaneously possesses CT and MRI imaging capabilities, its preparation method, and its application. The preparation method includes the following steps: dissolving bismuth citrate and iron salt in water, adjusting the pH of the solution to <7, adding polyvinylpyrrolidone, then adding gallic acid, adjusting the pH of the mixed solution to >7, and after the reaction is complete, filtering through a membrane to remove impurities, dialysis, and drying to obtain bismuth-iron nanoparticles; mixing citric acid with the bismuth-iron nanoparticle solution, stirring and reacting to obtain citric acid-treated bismuth-iron nanoparticles; further activating to obtain an activated bismuth-iron nanoparticle solution; adding RGDfk and amino-terminated polyethylene glycol to the activated bismuth-iron nanoparticle solution, stirring and reacting in the dark, dialysis, and drying to obtain a signal probe that simultaneously possesses CT and MRI imaging capabilities. The signal probe prepared by this invention has a small particle size and simultaneously possesses CT and MRI imaging functions.

The present invention relates to a wide-angle, large-aperture, fixed-focus lens, which is provided with a lens group, wherein the lens group includes a first lens with negative focal power, a second lens with negative focal power, a third lens with positive focal power, a fourth lens with negative focal power, a fifth lens with positive focal power, a sixth lens with positive focal power, a seventh lens with positive focal power, an eighth lens with negative focal power, and a ninth lens with positive focal power, which are sequentially arranged along the optical axis from the object side to the image side. The invention overcomes the disadvantage of the existing wide-angle, large-aperture, fixed-focus lens matching a 1 / 1.8" image plane chip, that the volume is large (the total optical length is long). By adopting the combination of nine lenses with optimal optical conditions, the total optical length is short, and the day and night confocality and high and low temperature drift compensation functions are realized.