- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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[IEEE 2019 International Conference on Optical MEMS and Nanophotonics (OMN) - Daejeon, Korea (South) (2019.7.28-2019.8.1)] 2019 International Conference on Optical MEMS and Nanophotonics (OMN) - Micro-optical system for depth-controlled Bessel beam arrays
摘要： We present an integrated, compact micro-optical system capable to generate depth-controlled Bessel beams by integrating a miniaturized adaptive liquid crystal ring aperture array with a micro-lens array, a lensacon, which is a combination of a lens and an axicon. We were able to successfully demonstrate a functional system that is able to generate and control Bessel beams.
关键词： micro-lens arrays,Bessel beam,micro-optical system,aspherical lenses,ring aperture,liquid crystal
更新于2025-09-16 10:30:52
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Single-Layer Series-Fed Planar Array with Controlled Aperture Distribution for Circularly Polarized Radiation
摘要： We propose a compact circularly polarized series-fed patch array with enhanced radiation performance at S-band. To our best knowledge, no similar single-layer structure has been designed, measured and reported in the literature with equivalent radiation performances in terms of reduced sidelobe-level (SLL) and aperture efficiency as well as compactness and simplicity. The planar array consists of a 50-? microstrip single feed point, offering uniform and efficient excitation of all its elements that enables a broadside beam with high-gain and low sidelobes. A feed network for such aperture control is designed and optimized to provide good impedance matching with a two-point excitation per radiating element, which is based on 0? and 90? meander lines to enable circularly polarized radiation. A structure made by a 4×1 arrangement of square patches is simulated, optimized, and manufactured, providing a realized gain of about 10 dBic and a SLL below ?15 dB. Very good axial ratios and high efficiencies are obtained. The proposed antenna may be of interest for next-generation far-field wireless power transmission systems and other applications including target tracking, radar and internet of things technologies requiring efficient circularly polarized radiation.
关键词： radar,series-fed array,Controlled aperture distribution,wireless power transfer,circular polarization
更新于2025-09-16 10:30:52
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Photonic crystal spatial filtering in broad aperture diode laser
摘要： Broad aperture semiconductor lasers usually suffer from low spatial quality of the emitted beams. Due to the highly compact character of such lasers, the use of conventional intracavity spatial ?lters is problematic. We demonstrate that extremely compact photonic crystal spatial ?lters, incorporated into a laser resonator, can improve the beam spatial quality and, correspondingly, increase the brightness of the emitted radiation. We report the decrease in the M2 value from 47 down to 28 due to photonic crystal spatial intracavity ?ltering and the increase in the brightness by a factor of 1.5, giving a proof of principle of intracavity photonic crystal spatial ?ltering in broad area semiconductor lasers.
关键词： photonic crystal,spatial filtering,beam quality,broad aperture diode laser,brightness
更新于2025-09-16 10:30:52
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Gnss Passive Radar Imaging Based on Differential Aperture
摘要： In this paper, a passive imaging scheme with differential aperture based on multiple GNSS satellites and multiple ground receivers is studied. Firstly, the passive imaging model with differential aperture is established. Then, the factors affecting spatial imaging resolution are analysed. Finally, an inversion method based on point-by-point matched filtering technology is presented. It is seen that the diversity of aperture can be used to compensate for the shortage of narrow bandwidth of GNSS signal, so as to improve the overall spatial resolution of passive radar. Simulation results verify effectiveness of related analysis.
关键词： spatial resolution improvement,differential aperture,GNSS passive imaging,matched filtering
更新于2025-09-16 10:30:52
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[IEEE 2019 International Conference on Advanced Electrical Engineering (ICAEE) - Algiers, Algeria (2019.11.19-2019.11.21)] 2019 International Conference on Advanced Electrical Engineering (ICAEE) - Feasibility study of grid-connected photovoltaic systems in small industrial enterprises
摘要： A novel design concept of multimode ?ltering antenna, which is realized by integrating a multimode resonator and an antenna, has been applied to the design of dual-polarized antenna arrays for achieving a compact size and high performance in terms of broad bandwidth, high-frequency selectivity and out-of-band rejection. To verify the concept, a 2 × 2 array at C-band is designed and fabricated. The stub-loaded resonator (SLR) is employed as the feed of the antenna. The resonant characteristics of SLR and patch as well as the coupling between them are presented. The method of designing the integrated resonator-patch module is explained. This integrated design not only removes the need for separated ?lters and traditional 50-Ω interfaces but also improves the frequency response of the module. A comparison with the traditional patch array has been made, showing that the proposed design has a more compact size, wider bandwidth, better frequency selectivity, and out-of-band rejection. Such low-pro?le light weight broadband dual-polarized arrays are useful for space-borne synthetic aperture radar (SAR) and wireless communication applications. The simulated and measured results agree well, demonstrating a good performance in terms of impedance bandwidth, frequency selectivity, isolation, radiation pattern, and antenna gain.
关键词： Antenna array,broadband,?ltering antenna,dual-polarization,synthetic aperture radar (SAR),stub-loaded resonator (SLR)
更新于2025-09-16 10:30:52
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Deep Learning for Photovoltaic Generation Forecast in Active Solar Trackers
摘要： With single-input single-output (SISO) SAR systems, employing a single transmitter and receiver beam, there exists a high resolution, wide swath contradiction. However, by using multiple receiver beams and employing array processing techniques, this contradiction can be overcome, allowing greater ?exibility and a wider range of application requirements to be met. In this paper the use of single-input multiple-output (SIMO) SAR systems for overcoming this contradiction is of interest, and a novel beamformer is proposed for processing in the cross-range direction. In order to fully describe the system, the array manifold vector is utilized, which is a key concept in the design of the beamformer. In particular, this beamformer is a superresolution beamformer capable of forming wide nulls using subspace based approaches and allows the suppression of ambiguities in multiple sets of received undersampled SAR data in the cross-range direction and reconstruction of the Doppler spectrum to form a single unambiguous set of SAR data. Compared to the existing reconstruction algorithm, only a single weighting vector is required for a block of ambiguous Doppler frequencies compared to a weight vector required for each ambiguous Doppler frequency. The capabilities of the proposed beamformer are shown to give an improved performance in ambiguity suppression via computer simulation studies in a representative maritime environment.
关键词： Single-input multiple-output (SIMO) synthetic aperture radar (SAR),array manifold vector,array processing.
更新于2025-09-16 10:30:52
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[IEEE 2019 International Conference on Optical MEMS and Nanophotonics (OMN) - Daejeon, Korea (South) (2019.7.28-2019.8.1)] 2019 International Conference on Optical MEMS and Nanophotonics (OMN) - A Large Aperture 2-Axis Electrothermal MEMS Mirror for Compact 3D LiDAR
摘要： Low-cost LiDAR with long distance, high resolution, and stable laser scanning are needed for robotics and automobiles. This paper reports a large-aperture, 2-axis electrothermal MEMS mirror for LiDAR applications. The MEMS mirror has a mirror plate of 2 × 2.5 mm2 and an optical field view (FoV) of 15° by 12°. The beam divergence of 0.5 mrad is achieved with a 1.3-mm laser beam. The rotational scanning resonant mode is at 0.7 kHz, which is achieved by the meshed bimorph actuators with improved stiffness.
关键词： large aperture,LiDAR,electrothermal actuation,MEMS micromirror
更新于2025-09-16 10:30:52
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[IEEE 2019 Radiation and Scattering of Electromagnetic Waves (RSEMW) - Divnomorskoe, Russia (2019.6.24-2019.6.28)] 2019 Radiation and Scattering of Electromagnetic Waves (RSEMW) - Multitier Omnidirectional Antenna on The Circular Waveguide with The Paired Slots on The Tiers
摘要： This paper presents a recon?gurable aperture-fed patch antenna array for ±45? polarizations. First, a new method to realize the recon?gurable ±45? polarizations is proposed. It introduces controllable RF switches on a cross-aperture to excite a square patch for two orthogonal polarizations. The RF switches are controlled by two sets of DC biases, which could select the polarization through the recon?gurable aperture. Second, two patch antennas based on cross-aperture excitation are discussed. The ?rst structure uses a split ground plane with four switches, while the other one employs a united ground plane with eight switches. Both antennas operate well as the single element. However, only the antenna with a united ground is suitable for developing a recon?gurable dual-polarized antenna array, owning to its simple DC biasing lines and the recon?gurable-controlling network. Both simulation and experiment studies were examined to verify the proposed design. The measured 10-dB impedance bandwidth of the array is 9.3%, which can cover the 2.4-GHz WLAN band. The desired radiation patterns were observed with a maximum gain of 13.5 dBi. The proposed antenna array has low cross-polarization and stable gain across the entire operating bandwidth.
关键词： ±45? Polarization,Polarization recon?gurable antenna array,PIN diodes,aperture-fed patch antenna
更新于2025-09-16 10:30:52
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[IEEE 2019 IEEE 3rd Advanced Information Management, Communicates, Electronic and Automation Control Conference (IMCEC) - Chongqing, China (2019.10.11-2019.10.13)] 2019 IEEE 3rd Advanced Information Management, Communicates, Electronic and Automation Control Conference (IMCEC) - Waveform Design for Airborne MIMO Radar with Inaccurate Priori Knowledge
摘要： Along-track multichannel synthetic aperture radar is usually used to achieve ground moving target detection and imaging. Nevertheless, there is a design dilemma between azimuth high resolution and wide swath (HRWS). To solve this problem in HRWS mode, we introduce a virtual multichannel (VMC) scheme. For each virtual channel, the low real pulse repetition frequency (PRF) improves the ability of resolving range ambiguity for wide-swath, and the high virtual PRF improves the capability of resolving Doppler ambiguity for azimuth high resolution. For multiple virtual channels, strong ground clutter is eliminated by the joint VMC processing. Furthermore, a detailed signal model of a moving target in the virtual channel is given, and the special false-peak effect in the azimuthal image is analyzed. Moreover, we propose a novel ground moving target processing method based on the VMC scheme and the clutter suppression interferometry (CSI) technique, which is called VMC-CSI. The integration of detection, location, velocity estimation, and imaging for ground moving targets can be achieved. Accounting for the unresolved main peak and false peak for a moving target, in the VMC-CSI method, we adopt a two-step scheme to estimate the radial velocity and along-track velocity, namely, rough estimation and precise estimation. Meanwhile, considering the same interferometric phases of the main peak and the false peak, we use false peaks first for the robustness of initial azimuth location estimation and remove false peaks afterward. Numerical simulations are provided for testing the effect of the false peak and the effectiveness of VMC-CSI.
关键词： high resolution and wide swath (HRWS),multichannel synthetic aperture radar (SAR),Ground moving target,virtual channel,SAR
更新于2025-09-16 10:30:52
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[IEEE IECON 2019 - 45th Annual Conference of the IEEE Industrial Electronics Society - Lisbon, Portugal (2019.10.14-2019.10.17)] IECON 2019 - 45th Annual Conference of the IEEE Industrial Electronics Society - Absolute Indoor Positioning-aided Laser-based Particle Filter Localization with a Refinement Stage
摘要： This paper introduces a framework for robust parameter estimation in multipass interferometric synthetic aperture radar (InSAR), such as persistent scatterer interferometry, SAR tomography, small baseline subset, and SqueeSAR. These techniques involve estimation of phase history parameters with or without covariance matrix estimation. Typically, their optimal estimators are derived on the assumption of stationary complex Gaussian-distributed observations. However, their statistical robustness has not been addressed with respect to observations with nonergodic and non-Gaussian multivariate distributions. The proposed robust InSAR optimization (RIO) framework answers two fundamental questions in multipass InSAR: 1) how to optimally treat images with a large phase error, e.g., due to unmolded motion phase, uncompensated atmospheric phase, etc.; and 2) how to estimate the covariance matrix of a non-Gaussian complex InSAR multivariate, particularly those with nonstationary phase signals. For the former question, RIO employs a robust M-estimator to effectively downweight these images; and for the latter, we propose a new method, i.e., the rank M -estimator, which is robust against non-Gaussian distribution. Furthermore, it can work without the assumption of sample stationarity, which is a topic that has not previously been addressed. We demonstrate the advantages of the proposed framework for data with large phase error and heavily tailed distribution, by comparing it with state-of-the-art estimators for persistent and distributed scatterers. Substantial improvement can be achieved in terms of the variance of estimates. The proposed framework can be easily extended to other multipass InSAR techniques, particularly to those where covariance matrix estimation is vital.
关键词： Differential interferometric synthetic aperture radar (D-InSAR),robust estimation,rank covariance matrix,robust InSAR optimization (RIO),M -estimator,SAR interferometry (InSAR)
更新于2025-09-16 10:30:52