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- 摘要
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[IEEE 2018 IEEE International Workshop on Electromagnetics: Applications and Student Innovation Competition (iWEM) - Nagoya (2018.8.29-2018.8.31)] 2018 IEEE International Workshop on Electromagnetics:Applications and Student Innovation Competition (iWEM) - E-Plane Beam-Forming Performance of Rotman-Lens in Multi-Layer Substrate
摘要： A two-dimensional Rotman-lens feeding circuit was proposed for planar two-dimensional multi-beam antenna using multi-layer substrate integrated waveguide in the millimeter-wave band. In this work, an E-plane Rotman-lens for two-dimensional Rotman-lens was designed and the E-plane beam-forming performance was evaluated by array factors from the simulated S-parameters.
关键词： multi-beam antenna,feeding circuit,multi-layer substrate,millimeter-wave,Rotman-lens
更新于2025-09-23 15:22:29
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Bias Impact Analysis and Calibration of Uav-Based Mobile Lidar System
摘要： Over the past few years, developments in mobile mapping technology, specifically Unmanned Aerial Vehicles (UAVs), have made accurate 3D mapping more feasible, thus emerging as an economical and practical mobile mapping platform. LiDAR-based UAV mapping systems are gaining widespread recognition as an efficient and cost-effective technique for rapid collection of 3D geospatial data. To derive point clouds with high positional accuracy, estimation of mounting parameters relating the laser scanners to the onboard GNSS/INS unit is the foremost and necessary step. In this paper, we first devise an optimal flight and target configuration by conducting a rigorous theoretical analysis of the potential impact of bias in mounting parameters of a LiDAR unit on the resultant point cloud. Then, we propose a LiDAR system calibration strategy that can directly estimate the mounting parameters for spinning multi-beam laser scanners onboard a UAV through an outdoor calibration procedure.
关键词： multi-beam laser scanners,UAV,GNSS/INS,mounting parameters,LiDAR
更新于2025-09-23 15:22:29
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[IEEE 2019 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Guangzhou, China (2019.5.19-2019.5.22)] 2019 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - A Circularly Polarized Substrate Integrated Waveguide Slot Array Antenna with Enhanced Scanning Range
摘要： In this paper, we report on an optical tolerance analysis of the submillimeter atmospheric multi-beam limb sounder, STEAMR. Physical optics and ray-tracing methods were used to quantify and separate errors in beam pointing and distortion due to re?ector misalignment and primary re?ector surface deformations. Simulations were performed concurrently with the manufacturing of a multi-beam demonstrator of the relay optical system which shapes and images the beams to their corresponding receiver feed horns. Results from Monte Carlo simulations show that the inserts used for re?ector mounting should be positioned with an overall accuracy better than 100 m ( 1/10 wavelength). Analyses of primary re?ector surface deformations show that a deviation of magnitude 100 m can be tolerable before deployment, whereas the corresponding variations should be less than 30 m during operation. The most sensitive optical elements in terms of misalignments are found near the focal plane. This localized sensitivity is attributed to the off-axis nature of the beams at this location. Post-assembly mechanical measurements of the re?ectors in the demonstrator show that alignment better than 50 m could be obtained.
关键词： Stratosphere–Troposphere Exchange And climate Monitor Radiometer (STEAMR),submillimeter-wave instruments,quasi-optics,multi-beam,tolerance analysis,Monte Carlo,Limb viewing
更新于2025-09-23 15:21:01
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Direct and High-Throughput Fabrication of Mie-Resonant Metasurfaces <i>via</i> Single-Pulse Laser Interference
摘要： High-index dielectric metasurfaces featuring Mie-type electric and magnetic resonances have been of a great interest in a variety of applications such as imaging, sensing, photovoltaics and others, which led to the necessity of an efficient large-scale fabrication technique. To address this, here we demonstrate the use of single-pulse laser interference for direct patterning of an amorphous silicon film into an array of Mie resonators with few hundred nanometers in diameter. The proposed technique is based on laser-interference-induced dewetting. A precise control of the laser pulse energy enables the fabrication of ordered dielectric metasurfaces in areas spanning tens of micrometers and consisting of thousands of hemispherical nanoparticles with a single laser shot. The fabricated nanoparticles exhibit a wavelength-dependent optical response with a strong electric dipole signature. Variation of the pre-deposited silicon film thickness allows tailoring of the resonances in the targeted visible and infrared spectral ranges. Such direct and high-throughput fabrication is a step towards a simple realization of spatially invariant metasurface-based devices.
关键词： direct laser interference patterning,metasurfaces,laser-matter interaction,dielectric nanostructures,silicon resonators,multi-beam interference
更新于2025-09-23 15:19:57
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Stable DFB Ridge Laser Diodes at 894nm at R.T. for Cesium Atomic Clocks
摘要： In this paper, we report on an optical tolerance analysis of the submillimeter atmospheric multi-beam limb sounder, STEAMR. Physical optics and ray-tracing methods were used to quantify and separate errors in beam pointing and distortion due to re?ector misalignment and primary re?ector surface deformations. Simulations were performed concurrently with the manufacturing of a multi-beam demonstrator of the relay optical system which shapes and images the beams to their corresponding receiver feed horns. Results from Monte Carlo simulations show that the inserts used for re?ector mounting should be positioned with an overall accuracy better than 100 m ( 1/10 wavelength). Analyses of primary re?ector surface deformations show that a deviation of magnitude 100 m can be tolerable before deployment, whereas the corresponding variations should be less than 30 m during operation. The most sensitive optical elements in terms of misalignments are found near the focal plane. This localized sensitivity is attributed to the off-axis nature of the beams at this location. Post-assembly mechanical measurements of the re?ectors in the demonstrator show that alignment better than 50 m could be obtained.
关键词： Stratosphere–Troposphere Exchange And climate Monitor Radiometer (STEAMR),multi-beam,quasi-optics,submillimeter-wave instruments,Limb viewing,Monte Carlo,tolerance analysis
更新于2025-09-19 17:13:59
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Tri-Focal Configuration of Three-Dimensional Metallic Waveguide-Array Lens Antennas of Rotman Lens Concept for Multi-Beam Applications
摘要： This paper presents a design methodology of three-dimensional (3-D) passive metallic waveguide-array lens antenna (MWALA) by implementing the Rotman lens concept (RLC) for collinear multi-beam radiations on the same angular plane. The RLC methodology extends the original concept of two-dimensional (2-D) tri-focal Rotman lens into a 3-D one in free space. Thus, the MWALA has a planar aperture facing to the radiation boresight to resemble a planar phased array of waveguide antennas and also has a curved focal surface pro?le (CFSP) on the opposite side to receive the illumination by the radiations of feed antennas. The three co-planar focal points are speci?ed to de?ne a circular focal arc (CFA) for multiple feed placement to radiate multi-beams through this MWALA. The boundary formed by the CFSP and CFA resembles the shape of Rotman lens equivalently realized in free space. In addition, the shortage of freedoms in conventional MWALA design limited to dual-focus con?gurations and resulting in narrow scan angles, is relaxed by adopting the phase velocities inside the waveguides as an additional freedom to realize a tri-focal con?guration and broaden the scan angles of multi-beam radiation. Theoretical foundation and design guidelines are summarized with numerical and experimental examples presented to validate the feasibility.
关键词： Antenna radiation,Rotman lens,multi-beam radiation,waveguide array lens antenna
更新于2025-09-19 17:13:59
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[IEEE 2018 International Conference on Intelligent Computing and Communication for Smart World (I2C2SW) - Erode, India (2018.12.14-2018.12.15)] 2018 International Conference on Intelligent Computing and Communication for Smart World (I2C2SW) - An Improved Transformerless Inverter Topology for Grid Connected Photovoltaic System
摘要： In this paper, we report on an optical tolerance analysis of the submillimeter atmospheric multi-beam limb sounder, STEAMR. Physical optics and ray-tracing methods were used to quantify and separate errors in beam pointing and distortion due to re?ector misalignment and primary re?ector surface deformations. Simulations were performed concurrently with the manufacturing of a multi-beam demonstrator of the relay optical system which shapes and images the beams to their corresponding receiver feed horns. Results from Monte Carlo simulations show that the inserts used for re?ector mounting should be positioned with an overall accuracy better than 100 m ( 1/10 wavelength). Analyses of primary re?ector surface deformations show that a deviation of magnitude 100 m can be tolerable before deployment, whereas the corresponding variations should be less than 30 m during operation. The most sensitive optical elements in terms of misalignments are found near the focal plane. This localized sensitivity is attributed to the off-axis nature of the beams at this location. Post-assembly mechanical measurements of the re?ectors in the demonstrator show that alignment better than 50 m could be obtained.
关键词： Stratosphere–Troposphere Exchange And climate Monitor Radiometer (STEAMR),submillimeter-wave instruments,quasi-optics,multi-beam,tolerance analysis,Monte Carlo,Limb viewing
更新于2025-09-19 17:13:59
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[IEEE 2019 24th OptoElectronics and Communications Conference (OECC) and 2019 International Conference on Photonics in Switching and Computing (PSC) - Fukuoka, Japan (2019.7.7-2019.7.11)] 2019 24th OptoElectronics and Communications Conference (OECC) and 2019 International Conference on Photonics in Switching and Computing (PSC) - Horizontal Slot Waveguides with Strong Optical Confinement in Low Refractive Index Oxide Films
摘要： In this paper, we report on an optical tolerance analysis of the submillimeter atmospheric multi-beam limb sounder, STEAMR. Physical optics and ray-tracing methods were used to quantify and separate errors in beam pointing and distortion due to re?ector misalignment and primary re?ector surface deformations. Simulations were performed concurrently with the manufacturing of a multi-beam demonstrator of the relay optical system which shapes and images the beams to their corresponding receiver feed horns. Results from Monte Carlo simulations show that the inserts used for re?ector mounting should be positioned with an overall accuracy better than 100 m ( 1/10 wavelength). Analyses of primary re?ector surface deformations show that a deviation of magnitude 100 m can be tolerable before deployment, whereas the corresponding variations should be less than 30 m during operation. The most sensitive optical elements in terms of misalignments are found near the focal plane. This localized sensitivity is attributed to the off-axis nature of the beams at this location. Post-assembly mechanical measurements of the re?ectors in the demonstrator show that alignment better than 50 m could be obtained.
关键词： multi-beam,submillimeter-wave instruments,tolerance analysis,Monte Carlo,Limb viewing,quasi-optics,Stratosphere–Troposphere Exchange And climate Monitor Radiometer (STEAMR)
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 69th Electronic Components and Technology Conference (ECTC) - Las Vegas, NV, USA (2019.5.28-2019.5.31)] 2019 IEEE 69th Electronic Components and Technology Conference (ECTC) - Active Control of NCF Fillet Shape for 3D CoW by Multi Beam Laser Bonder
摘要： Non-conductive film fillet control during the thermal compression bonding using a multi laser beam bonder investigated comparing with the case of using a conventional ceramic pulse heater bonder. The laser bonder can control each laser beam power individually, which can change the temperature distribution in the heated die. Fillet coverage index was defined as the ratio of the fillet width of the die corner and the maximum point of the die peripheral. The optimization of the temperature distribution of the die by the laser bonder could enlarge FCI from 0.25 with even reducing the fillet width at the maximum point of the die peripheral from 167 μm in comparison to those of 0.33 and 187 μm, which were obtained using a conventional bonder with a ceramics pulse heater, respectively.
关键词： laser bonder,fillet shape,High productivity,NCF,multi beam
更新于2025-09-16 10:30:52
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A multi-beam X-ray imaging detector using a branched optical fiber bundle
摘要： We developed a multi-beam X-ray imaging detector, consisting of four scintillator screens connected by a branched optical fiber bundle with a CMOS camera. By using the detector and a multi-beam imaging optics with silicon single crystalline blades designed for a white synchrotron radiation source, we successfully demonstrated multi-beam X-ray imaging with an exposure time of 1 ms. The long and flexible optical fiber bundle used for the detector enables us to realize high-speed multi-beam X-ray imaging with high flexibility at a relatively low cost.
关键词： synchrotron radiation,scintillator screens,optical fiber bundle,multi-beam X-ray imaging,CMOS camera
更新于2025-09-16 10:30:52