强激光与粒子束
2024, 36(4): 043013
强激光与粒子束
2024, 36(4): 043022
强激光与粒子束
2024, 36(1): 013011
1 国防科技大学 电子科学学院，长沙 410073
2 信息工程大学，郑州 450001
设计了一种工作在S波段的能量选择表面，可实现超宽带自适应强电磁防护。该结构由两层金属周期结构组成，顶层为两个对称分布的金属条和一个金属片，金属条与金属片间加载两个PIN二极管；底层为十字架结构。当入射电磁波场强低于阈值时，能量选择表面工作在透波状态，电磁波可以传播；当入射电磁波场强超过阈值时，金属条和金属片之间产生的感应电压使得PIN二极管导通，此时能量选择表面进入防护状态，电磁波被屏蔽。通过对能量选择表面在PIN二极管导通和截止状态下的表面电流和电场分布以及等效电路模型进行分析，解释了该结构的工作原理。采用PCB制作工艺加工了实物样板并对弱场入射下的插入损耗以及强场入射下的防护效能进行测试。实验和仿真结果匹配性良好，表明该能量选择表面在透波状态下的工作中心频率为2.7 GHz，插入损耗小于1 dB的工作频带为2.2～3.5 GHz；在防护状态下，工作频带的防护效能大于10 dB，达到了超宽带的要求。
能量选择表面 强电磁防护 S波段 超宽带 自适应响应 PIN二极管 energy selective surface strong electromagnetic protection ultra-wideband S-band adaptive respondse PIN diode 强激光与粒子束
2024, 36(3): 033003
Author Affiliations
Abstract
1 Guilin University of Electronic Technology, Photonics Research Center, School of Optoelectronic Engineering, Guilin, China
2 Guilin University of Electronic Technology, Guangxi Key Laboratory of Optoelectronic Information Processing, Guilin, China
3 Huazhong University of Science and Technology, Wuhan National Laboratory for Optoelectronics and School of Optical and Electronic Information, Wuhan, China
4 Optics Valley Laboratory, Wuhan, China
A pin-like beam is a kind of structured light with a special intensity distribution that can be against diffraction, which can be seen as a kind of quasi-nondiffracting beam (Q-NDB). Due to its wide applications, recently, numerous researchers have used optical lenses or on-chip integrated optical diffractive elements to generate this kind of beam. We theoretically verify and experimentally demonstrate an all-fiber solution to generate a subwavelength inverted pin beam by integrating a simple plasma structure on the fiber end surface. The output beams generated by two kinds of plasma structures, i.e., nanoring slot and nanopetal structure, are investigated and measured experimentally. The results show that both the structures are capable of generating subwavelength beams, and the beam generated using the nanopetal structure has the sidelobe suppression ability along the x-axis direction. Our all-fiber device can be flexibly inserted into liquid environments such as cell cultures, blood, and biological tissue fluids to illuminate or stimulate biological cells and molecules in them. It provides a promising fiber-integrated solution for exploring light–matter interaction with subwavelength resolution in the field of biological research.
inverted pin beam fiber-integrated plasma structure subwavelength resolution Advanced Photonics Nexus
2024, 3(2): 026003
1 中国民航大学 适航学院
2 民航航空器适航审定技术重点实验室, 天津 300300
为提高航空甚高频(VHF)通信设备的电磁防护能力, 提出了一种基于 PIN二极管的限幅器。采用先进设计系统 (ADS)仿真研究了不同二极管级数对限幅器插入损耗以及限幅性能的影响, 设计了一款由 PIN对管并联结构、集**数定向耦合器、整流电路与匹配电路相结合的半有源式限幅器, 通过将部分干扰信号转变为直流的方式, 为二极管提供偏置电压, 降低限幅器的限幅电平。性能测试结果表明, 在 118~136 MHz的频率范围内, 半有源式限幅器的插入损耗小于 1 dB, 输入输出端口的回波损耗大于 20 dB, 限幅电平小于 7.5 dBm, 功率容量大于 25 dBm, 实现了低插入损耗与高限幅性能。
航空甚高频通信 先进设计系统 PIN限幅器 电磁防护 aeronautical Very High Frequency communication Advanced Design System PIN limiter electromagnetic protection 太赫兹科学与电子信息学报
2023, 21(7): 928
Author Affiliations
Abstract
The comparison of domestic and foreign studies has been utilized to extensively employ junction termination extension (JTE) structures for power devices. However, achieving a gradual doping concentration change in the lateral direction is difficult for SiC devices since the diffusion constants of the implanted aluminum ions in SiC are much less than silicon. Many previously reported studies adopted many new structures to solve this problem. Additionally, the JTE structure is strongly sensitive to the ion implantation dose. Thus, GA-JTE, double-zone etched JTE structures, and SM-JTE with modulation spacing were reported to overcome the above shortcomings of the JTE structure and effectively increase the breakdown voltage. They provided a theoretical basis for fabricating terminal structures of 4H-SiC PiN diodes. This paper summarized the effects of different terminal structures on the electrical properties of SiC devices at home and abroad. Presently, the continuous development and breakthrough of terminal technology have significantly improved the breakdown voltage and terminal efficiency of 4H-SiC PiN power diodes.
PiN diode terminal structure mesa-JTE reverse breakdown voltage etching process Journal of Semiconductors
2023, 44(11): 113101
广东工业大学 省部共建精密电子制造技术与装备国家重点实验室, 广东 广州 510006
与其他压电材料相比, 1-3型压电单晶复合材料具有优异的压电性能和更匹配的声学特性, 更有利于制备出性能优异的超声换能器。该文通过有限元软件COMSOL对复合材料的振动模态及阻抗特性进行了系统的研究, 同时采用皮秒激光制备了高频1-3型Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3(PIN-PMN-PT)铁电单晶/环氧树脂复合材料,并进行了性能表征。该1-3复合材料机电耦合系数为0.65, 声阻抗为19.96 MRayls。该复合材料可用于制备高频超声换能器, 结果表明, 换能器中心频率为17.68 MHz, -6 dB带宽为84.38%, 插入损耗为-25.4 dB。
1-3型压电复合材料 Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3(PIN-PMN-P 皮秒激光 超声换能器 有限元 1-3 piezoelectric composite Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3(PIN-PMN-P picosecond laser ultrasonic transducer finite element analysis
1 湖北工业大学机械工程学院，湖北 武汉 430068
2 现代制造质量工程湖北省重点实验室，湖北 武汉 430068
印刷电路板上连接PIN正位度检测是保证PCB电气可靠性的重要环节，其主要检测PIN缺针、共线度与高度。为满足生产实际需求，提出一种基于双目视觉的连接PIN正位度检测方法。首先，通过双目标定获取相机内外参数，实现图像立体校正；其次，根据先验的相对方位和给定的排列信息生成相应的栅格，基于栅格灰度阈值变化进行PIN缺失检测；然后，分别提取PIN在两个相机视野中对应的特征角点，基于视差原理进行针尖三维坐标计算，实现对PIN的排列共线度检测；最后，提出了基于特征提取的PIN相对高度检测方法，实现了对PIN的相对高度检测。实验结果验证了所提方法的有效性，PIN相对高度检测的平均耗时为125.4 ms，精度达99.535%，重复性精度在±0.05 mm内。
双目视觉 PIN 正位度检测 视差 图像处理 激光与光电子学进展
2023, 60(14): 1415004
Author Affiliations
Abstract
1 School of Physics and Electronic Engineering, Harbin Normal University, Harbin 150025, P. R. China
2 Guangdong Provincial Key Laboratory of Electronic Functional Materials and Devices, Huizhou University, Huizhou 516001, P. R. China
3 School of Instrumentation Science and Engineering, Harbin Institute of Technology, Harbin 150080, P. R. China
4 School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, P. R. China
Relaxor-based ternary Pb()O3–Pb()O3–PbTiO3 (PIN–PMN–PT) single crystals and ceramics are promising candidates for high-performance electromechanical conversion devices. It is known that the domain structure and dielectric diffusion–relaxation characteristics are crucial to the excellent performances of relaxor ferroelectrics. In this work, we prepared the PIN–PMN–PT ceramics with various PIN/PMN proportions and systematically investigated their domain structure and dielectric diffusion–relaxation properties. The effect of PIN/PMN proportion on the domain size and dielectric diffusion–relaxation characteristics was also studied. The investigations showed that PIN–PMN–PT ceramics presented multi-type domain patterns comprising irregular island domains and regular lamellar domains. Moreover, the dependent relations of PIN/PMN proportions on the dielectric diffusion and domain size indicated that the PIN composition has a stronger lattice distortion than PMN composition; increasing the PIN proportion can enhance the dielectric diffusion and decrease the domain size. Our results could deepen the understanding of structure–property relationships of multicomponent relaxor ferroelectrics and guide the design and exploration of new high-performance ferroelectric materials.Relaxor-based ternary Pb()O3–Pb()O3–PbTiO3 (PIN–PMN–PT) single crystals and ceramics are promising candidates for high-performance electromechanical conversion devices. It is known that the domain structure and dielectric diffusion–relaxation characteristics are crucial to the excellent performances of relaxor ferroelectrics. In this work, we prepared the PIN–PMN–PT ceramics with various PIN/PMN proportions and systematically investigated their domain structure and dielectric diffusion–relaxation properties. The effect of PIN/PMN proportion on the domain size and dielectric diffusion–relaxation characteristics was also studied. The investigations showed that PIN–PMN–PT ceramics presented multi-type domain patterns comprising irregular island domains and regular lamellar domains. Moreover, the dependent relations of PIN/PMN proportions on the dielectric diffusion and domain size indicated that the PIN composition has a stronger lattice distortion than PMN composition; increasing the PIN proportion can enhance the dielectric diffusion and decrease the domain size. Our results could deepen the understanding of structure–property relationships of multicomponent relaxor ferroelectrics and guide the design and exploration of new high-performance ferroelectric materials.
Piezoelectric ceramics PIN–PMN–PT dielectric diffusion and relaxation characteristics domain structure Journal of Advanced Dielectrics
2022, 12(6): 2241002
