2024

• Record 25 of
  
  Title:Digital Twin System for Reflector Antenna Structure Performance Evaluation Based on Surrogate Model
  
  Author(s):Cui, Hanwei(1); Xiang, Binbin(1); Wang, Wei(2); Lian, Peiyuan(2); Zhou, Jianping(1); Lin, Shangmin(3)
  Source:2024 IEEE 7th International Conference on Electronic Information and Communication Technology, ICEICT 2024
  Volume:   Issue:   DOI: 10.1109/ICEICT61637.2024.10671104  Published: 2024  
  Abstract:The digital twin system of the reflector antenna based on the surrogate model is designed in this paper to achieve real-time evaluation of its structural performance during operation. Firstly, the finite element model of the reflector antenna is established, and mechanical performance data samples of the antenna structure are obtained. Secondly, using surrogate model technology, a high-precision Gaussian Process mathematical model is fitted to enable rapid and accurate prediction of the antenna structure's performance. Finally, data communication technology is utilized to connect the physical space of the antenna with its twin space, enabling visualization of its structure's performance and interaction with motion attitude based on the Unity engine. Through testing, it has been demonstrated that this digital twin system can achieve real-time monitoring of high precision and efficiency for the structural performance of the antenna. © 2024 IEEE.
  Accession Number: 20244117164549
• Record 26 of
  
  Title:Ladybeetle-I: Design of the brightest beacon lamp for LEO micro-satellite
  
  Author(s):Mei, Chao(1); Wang, Hua wei(1); Bo, Yi(1); Shi, Kui(1)
  Source:Proceedings of SPIE - The International Society for Optical Engineering
  Volume: 13156  Issue:   DOI: 10.1117/12.3015186  Published: 2024  
  Abstract:As a commercial aerospace education satellite, "Ladybeetle-I" has flashed many times around the world, which has attracted the attention of many astronomers. This manuscript presents the design of the beacon lamp of this satellite. Consider the limitation of low power consumption, small volume and light weight of "Ladybeetle-I", this beacon lamp is designed by the combination of light emitting diode (LED) array structure and total internal reflection (TIR) lens. Firstly, through the analysis of structure parameters, color temperature and working state of LED, the light source of the beacon lamp is realized. Secondly, through the analysis of the requirements parameter of TIR lens, the lens of the beacon lamp is realized. This beacon lamp realizes that the "Ladybeetle-I" in the 547-km LEO can be directly observed by naked eyes within the radius of more than 25 km. Furthermore, the satellite in-orbit test results show that the brightness of the beacon lamp at Sub-Satellite Point is higher than -0.6 magnitude (m) stars. To the best of our knowledge, "Ladybeetle-I", which utilizes this beacon lamp, is the first and only LEO satellite that can be directly observed by naked eye. © 2024 SPIE. All rights reserved.
  Accession Number: 20242016093078
• Record 27 of
  
  Title:Active Compensation of Reflector Antenna Structural Deformation Based on Deep BP-Neural Network
  
  Author(s):Zheng, Tianxiang(1); Xiang, Binbin(1); Lin, Shangmin(2); Wang, Wei(3); Lian, Peiyuan(3); Cui, Hanwei(1)
  Source:2024 IEEE 7th International Conference on Electronic Information and Communication Technology, ICEICT 2024
  Volume:   Issue:   DOI: 10.1109/ICEICT61637.2024.10671154  Published: 2024  
  Abstract:The active reflector is a method used to compensate for the surface deformation of the reflector due to gravity and other factors, which will lead to the degradation of the electromagnetic performance of the antenna. The time-invariant surface deformation of large antenna caused by wind cannot be compensated quickly and effectively. A method based on deep BP neural network (DBPNN) is proposed to quickly obtain the adjustment of active reflector actuators. The mapping relationship between the deformation of the primary reflector and the adjustment of thousands of actuators is established. In order to ensure the unity of data dimension, the relation matrix of the actuators and panels is established. By processing the deformation data of the primary reflector, the deformation and position characteristics of the panels are obtained, and the network parameters are trained by the Adam optimizer. The results show that the proposed method can obtain thousands of actuator adjustments at different elevation angles very quickly under the premise of meeting the accuracy requirements. Compared with the traditional numerical algorithm, this method is suitable for compensating the loss performance at all elevation angles, and the time of calculation is reduced significantly. © 2024 IEEE.
  Accession Number: 20244117164580
• Record 28 of
  
  Title:Research on Plasma Electrodeless High-Precision Spectral Calibration Light Source with Wide Spectrum Range
  
  Author(s):Pang, Ziliang(1); Zhen, Jingkun(2); Zhang, Yifan(3); Duan, Jingyao(1); Bai, Yong Lin(2); Song, Yuchao(4)
  Source:2024 25th International Conference on Electronic Packaging Technology, ICEPT 2024
  Volume:   Issue:   DOI: 10.1109/ICEPT63120.2024.10668744  Published: 2024  
  Abstract:Spectral calibration sources are essential for the calibration and characterization of spectroscopic detection equip-ment. This paper presents the design of an inductively coupled light source as a spectral calibration source. We employed a longitudinal magnetic field inductive discharge design, conducted a simulation analysis of the magnetic field distribution within this design, and solved the drift-diffusion equations to obtain the electron temperature and energy distribution of the generated plasma. The designed RF circuit has a stable resonant frequency at 13 MHz, and the operating power can be adjusted between o and 20 W. This device demonstrates excellent performance and stability, offering a longer lifespan compared to traditional calibration sources. © 2024 IEEE.
  Accession Number: 20244217191917
• Record 29 of
  
  Title:Key assembling and alignment technology of laser communication opto-mechanical system
  
  Author(s):Cao, Mingqiang(1); Lei, Yu(1); Shi, Yuanyuan(1); Ren, Wangtao(1); Liu, Yong(1); Li, Xiaoyan(1); Hou, Xiaohua(1)
  Source:Proceedings of SPIE - The International Society for Optical Engineering
  Volume: 13104  Issue:   DOI: 10.1117/12.3024118  Published: 2024  
  Abstract:The optical mechanical system of laser communication has the characteristics of compact structure, highly integration, and multi optical axes integration. The consistency between transmission and reception, divergence angle, and wavefront of the optical telescope of the system are very important indicators. In response to the above difficulties and characteristics, this article conducts research on computer-Aided adjustment, fiber optic coupling, and transceiver consistency testing. Currently, coaxial and off-Axis optical telescope aligning technologies, high-precision fiber optic coupling debugging technology, and turntable linked space optical path transceiver consistency assembling technology have been formed, which can achieve the target requirements of transceiver consistency of 3μrad and system divergence angle of 30μrad. © COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.
  Accession Number: 20241816027441
• Record 30 of
  
  Title:A Multi-plane 2D Medical Image Segmentation Method Combined with Transformers
  
  Author(s):Liu, Zengxin(1,2,3); Ma, Caiwen(1,2); She, Wenji(1,3)
  Source:Proceedings of SPIE - The International Society for Optical Engineering
  Volume: 13167  Issue:   DOI: 10.1117/12.3029806  Published: 2024  
  Abstract:Segmentation on medical image is a necessary prerequisite for disease diagnosis and treatment planning. In various medical image segmentation tasks, U-Net based on convolutional neural network (CNN) has achieved tremendous success due to its ability to learn image details and deep high-dimensional features. However, the inherent limitations of convolution operations limit their performance in modeling explicit long-term relationships. Especially in the brain MRI glioma segmentation task, traditional convolutional neural networks show weakness in learning global semantic information due to the extreme intrinsic heterogeneity of tumors in terms of appearance, shape, and histology. Therefore, this research proposes a 2D U-Net combined with transformer for brain tumor segmentation, and also designs a fusion module to better fuse the high-resolution detail features from the encoder with the high-level semantic features in the decoding process. The respective segmentation models are trained on the three orthogonal planes, and a tumor core-assisted network is separately trained. We validate proposed method on the BraTS20 brain glioma MRI dataset, and the experimental results demonstrate that our method outperforms state-of-the-art 2D methods. Compared with 3D methods, our model can accomplish accurate tumor segmentation while saving computational resources. © 2024 SPIE.
  Accession Number: 20242716656722
• Record 31 of
  
  Title:Polarization-independent metalens for broadband chromatic correction in the mid-wave infrared range
  
  Author(s):Zhao, Lv-Rong(1,2); Xu, Huang-Rong(1,2); Gao, Bo(1,2); Fan, Hao(1,2); Liu, Yi-Ming(1,2); Chen, Lu(1,2); Yu, Wei-Xing(1,2)
  Source:Proceedings of SPIE - The International Society for Optical Engineering
  Volume: 13153  Issue:   DOI: 10.1117/12.3018279  Published: 2024  
  Abstract:As one of the most promising schemes to address the bottleneck confronted by conventional optical devices (e.g., bulky sizes, high cost, and complex geometrical structure), metalens have drawn great attentions in the recent years. In this work, a metalens operating in mid-wave infrared (MW-IR) range is proposed, which can accomplish broadband achromatic under both x- and y-polarization incidence. In order to satisfy the strict phase requirements with relatively high transmission, three types of architectures composed of silicon symmetrical structures on a hexagonal magnesium fluoride substrate are delicately designed. In specific, these meta-atoms are supposed to simultaneously realize MW-IR waves focusing at 4.2 μm, and they can also compensate the phase differences between 3.7 to 4.2 μm. The numerical results indicate that the chromatic aberration in the concerned wavelength range can be well corrected for both x- and y-polarized incidence, and the corresponding maximum deviation values of focal length are only 3.10% and 3.09%, respectively. Moreover, the average focusing efficiencies of two different incidences are 51.15% and 49.01%, respectively. This work may have great potential to promote the integration of broadband MW-IR devices. © COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.
  Accession Number: 20242016087045
• Record 32 of
  
  Title:Influences on the propagation of light beams by the near surface layer of atmosphere and the correction methods
  
  Author(s):Yunqiang, Lai(1,2); Shangmin, Lin(1,2,3); Hu, Wang(1,2,3,4); Xuan, Zhang(1,3); Yu, Jin(1,2); Wenlong, He(1,2); Yaoke, Xue(1,2,3)
  Source:Proceedings of SPIE - The International Society for Optical Engineering
  Volume: 13156  Issue:   DOI: 10.1117/12.3019539  Published: 2024  
  Abstract:With the increasingly widespread and important application of optics in modern human life and production, research on the propagation characteristics and correction methods of light beams in the atmosphere near the ground surface is becoming increasingly important. The complex atmospheric environment near the ground can affect the propagation of light beams, causing effects such as energy attenuation, beam expansion, beam drift, intensity flicker, phase fluctuations, etc., reducing the quality of beam propagation and affecting the performance of optical applications in various fields. A review was conducted on the impact of near-Earth atmosphere on beam propagation and its correction methods, mainly elaborating on the effects of atmospheric absorption, scattering, and turbulence on beam propagation. Correction methods such as adaptive optics, large aperture receiving, spatial diversity, partially coherent light propagation, and image processing are proposed. © 2024 SPIE. All rights reserved.
  Accession Number: 20242016093105
• Record 33 of
  
  Title:Research on Moving Targets Detection and Tracking Satellite System
  
  Author(s):Chang, Wujun(1); Jiang, Xiupeng(1); Gao, Enyu(1); Qin, Jing(2); Chen, Rongli(3); Su, Fan(1); Diao, Zhanlin(1); Gao, Shuai(1); Jia, Zhihui(1)
  Source:ACM International Conference Proceeding Series
  Volume:   Issue:   DOI: 10.1145/3679431.3679516  Published: May 24, 2024  
  Abstract:For the problem of detection, stable tracking and positioning of moving targets in complex scene, an optical detection and tracking system for LEO dual-satellite formation is constructed, the continuous tracking observation performance of the dual-satellite system was analyzed, and a dual-satellite target positioning model was established. Hyperspectral, infrared and other optical detection means were used, combined with target detection and tracking algorithms, and the engineering design method of satellite key technologies were proposed and in-orbit application verification was carried out. The conclusion is that the technology in this paper can achieve effective detection and perception of wide-area moving targets, continuous real-time monitoring and rapid precise positioning. © 2024 ACM.
  Accession Number: 20243917085280
• Record 34 of
  
  Title:Research of laser atmospheric propagation of large-aperture antenna measurement
  
  Author(s):Zhang, Xuan(1); Gao, Ming(1); Wang, Hu(1,2,3,4,5); Lin, Shangmin(2,3,4); Jin, Yu(2,3); Lai, Yunqiang(2,3); Lv, Hong(1); He, Wenlong(2,3)
  Source:Proceedings of SPIE - The International Society for Optical Engineering
  Volume: 13070  Issue:   DOI: 10.1117/12.3021213  Published: 2024  
  Abstract:Laser measurement technology is widely used in antenna main reflector and subreflector deformation or pose measurement. Based on the laser measurement technology, atmospheric turbulence caused by the atmospheric characteristics or the convergence effect of the antenna itself will affect the refractive index disturbance during laser propagation, which affects the accuracy of the laser measurement of the antenna deformation or pose. In order to solve the problem of laser atmospheric propagation deflection caused by atmospheric turbulence on the near-ground of a large-aperture antenna, firstly, this paper decomposes the laser atmospheric propagation path into multiple isotropic air layers, calculates the atmospheric refractive index of each air layer, obtains the atmospheric refractive index of the whole laser propagation path through curve fitting methods, and then assesses the laser deflection. Secondly, the turbulence intensity under sunny daytime and cloudy nighttime are evaluated, the laser spot position deviation is compared and analyzed, and the matching relationship among turbulence intensity, theoretical deviation of the laser spots, and actual spot deviation is obtained. Finally, the deflection of laser atmospheric propagation is fitted and calculated by measuring environmental data matched to the actual experimental data of the Nanshan 26m radio telescope antenna, which verifies the effectiveness and feasibility of the proposed method. © COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.
  Accession Number: 20241315797460
• Record 35 of
  
  Title:Research on Laser Spectrum of Large-aperture Antenna Subreflector Pose Measurement
  
  Author(s):Xuan, Zhang(1); Shangmin, Lin(2,3,4); Hu, Wang(1,2,3,4,5); Ming, Gao(1); Zhen, Wang(2); Yu, Jin(2,3); Jiang, Qiao(2,3); Yunqiang, Lai(2,3); Wenlong, He(2,3); Yaoke, Xue(2,3,6,7)
  Source:Proceedings of SPIE - The International Society for Optical Engineering
  Volume: 13156  Issue:   DOI: 10.1117/12.3022954  Published: 2024  
  Abstract:When the large-aperture antenna pose is measured by the laser method, the subreflector has a strong energy due to the convergence of the antenna itself and the instability of the near-ground atmosphere, and then the laser signal is easily drowned out. Atmospheric attenuation and other factors will weaken the laser transmission in different spectral bands, which reduces the recognition accuracy of laser spots. Aiming at the research of measuring the laser spectrum of large-aperture antenna, this paper analyzes the influence of atmospheric attenuation on the signals of different laser spectrum bands under the fixed distance of subreflector measurement, and compares the solar radiation energy of different wavelengths in laser. Finally, the stray light simulation analysis and experiments are carried out on different laser working spectrum bands to verify the accuracy of the spectrum research used in antenna measurement. Experiments show that the 1064 nm wavelength spectrum, as the working spectral band of the antenna measurement, the spot information is more obvious, which can effectively realize the extraction and identification of the spot center and provide a strong guarantee for the antenna pose measurement. © 2024 SPIE. All rights reserved.
  Accession Number: 20242016093111
• Record 36 of
  
  Title:A High-Power Lateral p-i-n Silicon-Germanium Photodiode
  
  Author(s):Cheng, Chao(1,2); Xue, Jintao(1,2); Yu, Zhiyuan(1); Wu, Jinyi(1,2); Bao, Shenlei(1,2); Wang, Binhao(1,2)
  Source:2024 Photonics and Electromagnetics Research Symposium, PIERS 2024 - Proceedings
  Volume:   Issue:   DOI: 10.1109/PIERS62282.2024.10618558  Published: 2024  
  Abstract:Silicon-germanium (Si-Ge) photodiodes are a crucial component in silicon photonic integrated circuits, responsible for detecting and converting optical signals into electrical signals. This paper introduces a laterally-coupled p-i-n Si-Ge photodiode with a silicon nitride (Si3N4) waveguide and a Si3N4 coating layer on germanium, enhancing responsivity at high optical power mode without compromising 3 dB opto-electrical (OE) bandwidth. The proposed photodiode exhibits a responsivity of 0.62 A/W and an OE bandwidth of 60 GHz at a reverse bias of 2 V and an input optical power of 6 mW. This study offers a new perspective on optimizing high-speed and high-power Si-Ge photodiodes. © 2024 IEEE.
  Accession Number: 20243516940648