- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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[IEEE OCEANS 2019 MTS/IEEE SEATTLE - Seattle, WA, USA (2019.10.27-2019.10.31)] OCEANS 2019 MTS/IEEE SEATTLE - Polarized Complex Modulation for Underwater Wireless Optical Communications
摘要： We describe a novel iterative methodology for computing a set of low-sidelobe beamforming weights for an airborne, electronically-steered phased-array radar using an in-flight stochastic optimization routine performed over a number of coherent processing intervals (CPIs). The proposed approach is notable in that it does not rely upon a good antenna calibration and only requires digitization of the radar’s sum beam. By observing the radar ground clutter, the algorithm iteratively adjusts the beamformer. Furthermore, it is computationally inexpensive and scales favorably to radars comprising very large numbers of antenna elements and requiring extremely low sidelobes.
关键词： radar,clutter,iterative,Calibration,stochastic optimization,phased arrays
更新于2025-09-19 17:13:59
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CMOS-Compatible Optical Phased Array Powered by a Monolithically-Integrated Erbium Laser
摘要： An advanced CMOS-compatible 300-mm-wafer silicon-photonics platform is introduced that consists of a silicon layer with eight doping masks, two silicon-nitride layers, three metal and via layers, a dicing trench for smooth edge-coupled facets, and a gain-film trench that enables interaction between the gain material and waveguide layers. The platform was used to demonstrate an electrically-steerable integrated optical phased array powered by an on-chip erbium-doped laser. Lasing with a single-mode output, 30 dB side-mode-suppression ratio, and 40 mW lasing threshold was shown, and one-dimensional beam steering with a 0.85? × 0.20? full-width at half-maximum and 30?/W electrical steering efficiency was demonstrated. This system represents the first demonstration of a rare-earth-doped laser monolithically integrated with an active CMOS-compatible silicon-on-insulator photonics system.
关键词： Silicon photonics,rare-earth-doped lasers,integrated optical phased arrays,photonic integrated circuits
更新于2025-09-19 17:13:59
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Formation of the Feedback Loop for Phase Control of a Fiber Laser Array
摘要： Methods for phasing radiation channels for the coherent combination of linearly polarized fields of narrowband fiber lasers are considered. High efficiency of operation of the internal feedback loop based on interference of peripheral sections of radiation (Gaussian beam tails) of the phased channels is shown. This method is easily implementable. It allows scaling the power of optical phased arrays and does not require heavy optical elements. Equations for calculation of the optical scheme for implementation of the feedback loop are presented along with the experimental results on coherent combination of three beams.
关键词： optical phased arrays,feedback loop,coherent combining,fiber laser
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Molecular Beam Epitaxy of Wide-Bandgap InAlAsSb on InP Substrates for an All Lattice-Matched Triple-Junction Solar Cell
摘要： The Kilpisj?rvi Atmospheric Imaging Receiver Array (KAIRA) is a dual array of omnidirectional VHF radio antennas located near Kilpisj?rvi, Finland. It is operated by the Sodankyl? Geophysical Observatory. It makes extensive use of the proven LOFAR antenna and digital signal-processing hardware, and can act as a stand-alone passive receiver, as a receiver for the European Incoherent Scatter (EISCAT) very high frequency (VHF) incoherent scatter radar in Troms?, or for use in conjunction with other Fenno-Scandinavian VHF experiments. In addition to being a powerful observing instrument in its own right, KAIRA will act as a pathfinder for technologies to be used in the planned EISCAT_3-D phased-array incoherent scatter radar system and participate in very long baseline interferometry experiments. This paper gives an overview of KAIRA, its principal hardware and software components, and its main science objectives. We demonstrate the applicability of the radio astronomy technology to our geoscience application. Furthermore, we present a selection of results from the commissioning phase of this new radio observatory.
关键词： receiving antennas,radio astronomy,radar antennas,Antenna arrays,phased arrays
更新于2025-09-16 10:30:52
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A Lateral MOS-Capacitor Enabled ITO Mach-Zehnder Modulator for Beam Steering
摘要： Here, we experimentally demonstrate an Indium Tin Oxide (ITO) Mach-Zehnder interferometer heterogeneously integrated in silicon photonics. The phase shifter section is realized in a novel lateral MOS configuration, which, due to favorable electrostatic overlap, leads to efficient modulation (VπL = 63 V.μm). This is achieved by (i) selecting a strong index changing material (ITO) and (ii) improving the field-overlap as verified by the electrostatic field lines. Furthermore, we show that this platform serves as a building block in an end-fire silicon photonics optical phased array (OPA) with a half-wavelength pitch within the waveguides with anticipated performance, including narrow main beam lobe (<3°) and >10 dB suppression of the side lobes, while electrostatically steering the emission profile up to ±80°, and if further engineered, can lead not only towards nanosecond-fast beam steering capabilities in LiDAR systems but also in holographic display, free-space optical communications, and optical switches.
关键词： Electro-optic Modulator,Indium Tin Oxide (ITO),Phased Arrays,LiDAR,Mach Zehnder,Beam Steering
更新于2025-09-16 10:30:52
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[IEEE 2019 49th European Microwave Conference (EuMC) - Paris, France (2019.10.1-2019.10.3)] 2019 49th European Microwave Conference (EuMC) - Design of Aperture Coupled Feeding Ku-Band Phased Array Antenna on Multi-Layer PCB for Satellite Communications
摘要： In a phased array antenna system, beamforming integrated circuit (IC) is located directly behind the antenna and uses a multi-layer printed circuit board (PCB). As the frequency band becomes higher, the direct via feed method is not suitable for multi-layer PCB structure due to the decrease of transmission characteristics and the increase of manufacturing difficulty by use of blind via. This paper introduces the antenna using an aperture coupled feeding technique on multi-layer PCB for a Ku-band phased array antenna system. To verify the design, an antenna prototype is developed and measured at Ku-band for satellite applications. The antenna operates with left-handed circular polarization (LHCP) at center frequency of 11.9GHz and a peak gain of 15.2dBic.
关键词： automotive applications,Ku-band,slot antennas,satellite communication,phased arrays
更新于2025-09-12 10:27:22
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Mode Engineering in Linear Coherently Coupled Vertical Cavity Surface Emitting Laser Arrays
摘要： The supermode tuning of coherent 3×1 vertical-cavity surface-emitting laser arrays are characterized and simulated. The array elements are resonantly tuned to achieve coherent operation using selective current injection. Depending on the electrical bias, multiple coherent supermodes are observed above threshold. An effective index model is developed to account for the variable current injection and to simulate the supermodes of the linear array. Agreement between experimental near-field and far-field coherent modes and our model simulations are found both at and above lasing threshold.
关键词： semiconductor laser arrays,Laser modes,phased arrays,vertical cavity surface emitting lasers (VCSELs)
更新于2025-09-11 14:15:04
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Relativistic microwave oscillators with high power flux in a free space and interaction zone
摘要： In the recent two decades, high-power microwave (HPM) generators producing short Ka-band and X-band pulses were intensively investigated (see Refs. [1–6] and citation therein). For generation of HPM pulses with duration of units of nanosecond and less influence of microwave breakdowns of electrodynamics systems, expansion of cathode and collector plasmas, and electron beam structure distortions becomes insignificant. Though the pulse duration is short, the radiating energy rises if coherent summation of radiation from several generators is provided. When the power in each channel is high, the wave beam could be formed where power flux density is limited only by breakdown strength of the media. Using approaches of the phased arrays, the directional pattern (DP) of summarized radiation could be steered. This is achievable from pulse to pulse, as well as during a single nanosecond pulse if summarized wave beams have a shifted frequencies. The related experiments with Ka-band microwave pulses are presented below.
关键词： directional pattern,Ka-band,phased arrays,superradiance,microwave breakdowns,backward-wave oscillators,X-band,coherent summation,high-power microwave
更新于2025-09-10 09:29:36
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Improving the Performance of the Optical Antenna for Integrated LIDAR with Optical Phased Arrays through High Contrast Grating Structure on SOI Substrate
摘要： A novel optical antenna for integrated LIDAR with optical phased arrays is proposed and simulated. A HCG structure is used to achieve extremely efficient emission. The emission efficiency is as high as 93.94% at 1550 nm, which exceeds 50% in a range of wavelength from 1480 nm to 1620 nm. The antenna can achieve a perfect grating lobe suppression with background suppression of 28.4dB when the phase difference between adjacent waveguides is 0. A 16-wire optical phased arrays LIDAR can easily achieve a scan range of ±22.8°×20.2° with a beam width of 2.4°×2.5°, by employing the optical antenna proposed.
关键词： SOI substrate,high contrast grating,optical phased arrays,LIDAR,optical antenna
更新于2025-09-10 09:29:36
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Automatic Monitor-Based Tuning of an RF Silicon Photonic 1X4 Asymmetric Binary Tree True-Time-Delay Beamforming Network
摘要： Photonic beamforming networks are promising candidates to achieve power-efficient transmission in future cellular communication systems. However, sensitivity to process and temperature variations necessitates an automatic calibration solution to enable robust operation. This paper demonstrates fully automatic monitor-based tuning of an integrated optical ring resonator-based 1X4 asymmetric binary tree optical beamforming network (OBFN). The proposed monitor-based tuning algorithm compensates fabrication variations and thermal crosstalk by controlling micro-heaters individually using information from electrical monitors. This algorithm is demonstrated on an OBFN that operates at 30 GHz with 2 GHz bandwidth and is fabricated in a standard silicon photonics foundry process. Successful calibration of the OBFN from a severely degraded initial response to the well-defined group delay responses required for a targeted radiating angle over 60? (?30? to 30?) in a linear beamforming antenna array is achieved. This fully automatic tuning approach opens the possibility of employing silicon OBFNs in real wideband mm-wave wireless communication systems.
关键词： optical ring resonators,thermal crosstalk,photonic integrated circuits,phased arrays,RF photonics,optical beamforming,true time delays,Microwave photonics
更新于2025-09-09 09:28:46