- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Mm-Wave Beam-Steering Focal Plane Arrays with Microfluidically Switched Feed Networks
摘要： Micro?uidically switched feed networks are introduced to realize millimeter-wave beam-steering focal plane arrays (FPAs). Switching functionality is achieved by a selectively metallized plate (SMP) repositionable within a micro?uidic channel that is brought in close proximity to the microstrip line feed network of an FPA. The feed network is strategically designed to exhibit gap discontinuities that are sequentially overlapped by the SMP metallizations. The capacitive couplings between the SMP metallizations and the gap discontinuities are designed to achieve wideband (～20 GHz) switching functionality with low insertion loss (IL < 0.2 dB). Transmission line theory is utilized to demonstrate that the feed network offers 38% fractional bandwidth with ≤7 dB IL for linear arrays of 32 elements. This performance constitutes a signi?cant improvement over the recently reported resonant feed network based realization of micro?uidic beam-steering FPAs (MFPAs). Experimental veri?cation is carried out through the design and fabrication of a 30 GHz eight-element FPA. The FPA exhibits measured gains ranging between 20.2 and 22.6 dBi. Loss budget breakdown con?rms the low-loss performance of the micro?uidically switched feed networks (≤3 dB). The required micro?uidic actuation range is 4.2 mm and 10× lower than that of the prior work. This allows to achieve a faster beam-steering speed (0.27 s versus 5.25 s of previous designs). An integrated sensing approach for detecting the SMP position is also presented for the ?rst time to facilitate the use of presented MFPAs with closed-loop position control.
关键词： milimeter-wave,micro?uidics,focal plane arrays (FPAs),Ka-band,recon?gurable antenna,Beam-steering
更新于2025-09-23 15:21:01
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Sampled-Data Adaptive ESO Based Composite Control for Nano-Positioning Systems
摘要： In this paper, we demonstrate ultra-fast millimeter wave beam steering with settling times below 50 ps. A phased array antenna with two elements is employed to realize beam steering. The phased array feeder is implemented with a recently introduced time delay line that provides, at the same time, an ultra-fast tunability, broadband operation, and continuous tuning. Our implementation is used to perform symbol-by-symbol steering. In our demonstration, the beam direction is switched between two sequentially transmitted symbols toward two receivers placed 30° apart. We show the successful symbol-by-symbol steering for data streams as fast as 10 GBd. The suggested scheme shows that the ultra-fast beam steering is becoming practical and might ultimately enable novel high bit-rate multiple access schemes.
关键词： microwave photonics,millimeter wave communication,Ultra-fast beam steering,radio access network
更新于2025-09-23 15:19:57
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Electronically controlled beam steering leaky wave antenna in nematic liquid crystal technology
摘要： A novel nematic liquid crystal (LC) technology-based electronically controlled leaky wave antenna (LWA) with microstrip-waveguide conversion working mechanism and wide beam steering range is presented in this article. The LWA is a combination of an inverted microstrip structure and rectangular waveguide. According to the characteristics of LC materials in microwave band, a broadband microstrip-waveguide conversion device is proposed. The gradient slot leaky wave structure is combined with the microstrip-waveguide conversion device to form an electronically controlled LWA with continuous tunable beam. Simulation and experiment results show that the LWA proposed in this article has a 32° beam scanning range at 12 GHz and good impedance matching and stable gain, suggesting the great potential of nematic LC materials for extensive applications in microwave band in the future.
关键词： leaky wave antenna (LWA),microstrip-waveguide conversion,beam steering,nematic,liquid crystal (LC)
更新于2025-09-23 15:19:57
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Graphene-Based Composite Right/Left-Handed Leaky-Wave Antenna at Terahertz
摘要： In this paper, a simple terahertz (THz) leaky-wave antenna (LWA) composed of periodic gapped graphene ribbons and a silicon substrate is presented. The graphene sheets of the antenna operate in an electric field with a resonance distribution of transverse electric (TE) surface plasmon polaritons (SPPs). The THz LWA has both negative and positive propagation constant with the variation of frequencies. Thus, the LWA performs as a composite right/left-handed (CRLH) LWA with backfire-to-endfire beam steering capability in the THz band. The working principle of the THz LWA is analyzed in detail using the theory of dispersion relation formulae and the equivalent CRLH circuit model. The THz LWA is verified by numerical simulations, and the frequency scannable capability of the THz LWA is confirmed. The proposed antenna has great potential applications for the THz LWA of the radiation capability in the entire upper quadrants.
关键词： Composite right/left-handed,Terahertz,Beam-steering,Graphene,Leaky-wave antenna
更新于2025-09-23 15:19:57
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[Institution of Engineering and Technology 8th Renewable Power Generation Conference (RPG 2019) - Shanghai, China (24-25 Oct. 2019)] 8th Renewable Power Generation Conference (RPG 2019) - Design of general framework for multifault diagnosis based on photovoltaic grid-connected inverter system
摘要： Visible light communication (VLC) systems have typically operated at data rates below 10 Gb/s and operation at this data rate was shown to be feasible by using laser diodes (LDs), imaging receivers and delay adaptation techniques (DAT imaging LDs-VLC). However, higher data rates, beyond 10 Gb/s, are challenging due to the low signal to noise ratio (SNR) and inter symbol interference (ISI). In this paper, for the first time, to the best of our knowledge, we propose, design, and evaluate a VLC system that employs beam steering (of part of the VLC beam) using adaptive finite vocabulary of holograms in conjunction with an imaging receiver and a DAT to enhance SNR and to mitigate the impact of ISI at high data rates (20 Gb/s). An algorithm was used to estimate the receiver location, so that part of the white light can be directed towards a desired target (receiver) using beam steering to improve SNR. Simulation results of our location estimation algorithm (LEA) indicated that the required time to estimate the position of the VLC receiver is typically within 224 ms in our system and environment. A finite vocabulary of stored holograms is introduced to reduce the computation time required by LEA to identify the best location to steer the beam to the receiver location. The beam steering approach improved the SNR of the fully adaptive VLC system by 15 dB at high data rates (20 Gb/s) over the DAT imaging LDs-VLC system in the worst-case scenario. In addition, we examined our new proposed system in a very harsh environment with mobility. The results showed that our proposed VLC system has strong robustness against shadowing, signal blockage, and mobility.
关键词： delay adaptation,SNR,location estimation,imaging receiver,Beam steering,finite vocabulary of holograms,ISI,laser diodes
更新于2025-09-23 15:19:57
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Spina??Controlled Nonlinear Harmonic Generations from Plasmonic Metasurfaces Coupled to Intersubband Transitions
摘要： Metasurfaces that generate nonlinear optical responses provide new degrees of freedom for applications such as nonlinear holography, wave mixing, and new frequencies generation. To extend the utility of flat nonlinear optics, metasurfaces providing both giant nonlinear response for efficient frequency mixing in subwavelength films and a single-beam output with a local wavefront control need to be developed. Metasurfaces with giant nonlinear response have recently been realized using the concept of intersubband polaritons. Separately, nonlinear metasurfaces providing a single-beam nonlinear output with a local wavefront control have been studied. However, a metasurface platform that possesses both of these properties has yet to be demonstrated. Herein, the first such platform is presented and its operation for three- and four-wave mixing processes is demonstrated. This approach is based on using Pancharatnam–Berry phase control of local nonlinear response and on employing meta-atoms with specific symmetries to enable generation of only a single nonlinear beam. Experimentally, 400 nm-thick metasurfaces with a wavefront-controlled single-beam output are demonstrated for second- and third-harmonic generation at pump wavelength of approximately 10 μm. Power conversion efficiencies of 7.6 × 10?4% and 3.6 × 10?4% are obtained for the two nonlinear processes, respectively, at peak pumping intensity of only 80 kW cm?2.
关键词： nonlinear beam-steering,nonlinear optics,spin angular momentum,metasurfaces,intersubband transitions
更新于2025-09-23 15:19:57
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[IEEE 2018 IEEE International Symposium on Antennas and Propagation & USNC/URSI National Radio Science Meeting - Boston, MA, USA (2018.7.8-2018.7.13)] 2018 IEEE International Symposium on Antennas and Propagation & USNC/URSI National Radio Science Meeting - A Circularly Polarized Triple-Feed Multi-Beam Array Antenna Using Planar Magic- Ts
摘要： A circularly polarized triple-feed multi-beam array antenna employing two types of planar magic-Ts is proposed. The proposed array antenna, where each of the antenna elements are circularly polarized antennas provides three different radiation patterns in the x-z and y-z planes. The performance of the proposed antenna is experimentally evaluated. The 10-dB impedance bandwidth of the antenna is better than 3.1% and 3-dB axial ratio bandwidth is 0.81%. All these features make the proposed antenna very suitable for direction-of-arrival estimation antennas, beam steering antennas and wide-angle rectennas.
关键词： magic-T,wide-angle rectenna,direction-of-arrival estimation antenna,triple-feed,beam steering antenna
更新于2025-09-19 17:15:36
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Single-Layer Bifacial Metasurface: Full-Space Visible Light Control
摘要： Optical metasurfaces have attracted considerable attention thanks to their unprecedented ability to control the electromagnetic properties of light in subwavelength scale. These metasurface-integrated devices not only have the merit of compact form factor but also exhibit some better performance in comparison with conventional bulk optic devices. In this work, a novel metasurface that enables full-space light control is realized, offering an unconventional functionality that provides a new foothold for metasurface integration in optics. Multipolar interference and Pancharatnam–Berry phase are combined with each other and suggested as a physical background for the proposed device. As an example of the functionality, asymmetric beam steering and hologram generation are proposed and measured experimentally. As far as it is known, this is the first work achieving full-space control in visible range. Thanks to its manufactural ease and unprecedented function capability, this work will offer innovative potentials to be utilized in various integrated optic devices that need miniaturization or implementation of ingenious and light-weight optical components used in optical systems for photography, microscopy, computer vision, etc.
关键词： beam steering,metamaterials,multifunctional devices,holography,metasurfaces
更新于2025-09-19 17:15:36
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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) - Analysis of Inverse Lifetime Curves of TaO <sub/>x</sub> Electron-Selective Contacts for Si Solar Cells
摘要： Visible light communication (VLC) systems have typically operated at data rates below 10 Gb/s and operation at this data rate was shown to be feasible by using laser diodes (LDs), imaging receivers and delay adaptation techniques (DAT imaging LDs-VLC). However, higher data rates, beyond 10 Gb/s, are challenging due to the low signal to noise ratio (SNR) and inter symbol interference (ISI). In this paper, for the first time, to the best of our knowledge, we propose, design, and evaluate a VLC system that employs beam steering (of part of the VLC beam) using adaptive finite vocabulary of holograms in conjunction with an imaging receiver and a DAT to enhance SNR and to mitigate the impact of ISI at high data rates (20 Gb/s). An algorithm was used to estimate the receiver location, so that part of the white light can be directed towards a desired target (receiver) using beam steering to improve SNR. Simulation results of our location estimation algorithm (LEA) indicated that the required time to estimate the position of the VLC receiver is typically within 224 ms in our system and environment. A finite vocabulary of stored holograms is introduced to reduce the computation time required by LEA to identify the best location to steer the beam to the receiver location. The beam steering approach improved the SNR of the fully adaptive VLC system by 15 dB at high data rates (20 Gb/s) over the DAT imaging LDs-VLC system in the worst-case scenario. In addition, we examined our new proposed system in a very harsh environment with mobility. The results showed that our proposed VLC system has strong robustness against shadowing, signal blockage, and mobility.
关键词： SNR,finite vocabulary of holograms,ISI,Beam steering,delay adaptation,imaging receiver,location estimation,laser diodes
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) - Intense Pulsed Light Meets the Metallization of Silicon Heterojunction Solar Cells
摘要： Visible light communication (VLC) systems have typically operated at data rates below 10 Gb/s and operation at this data rate was shown to be feasible by using laser diodes (LDs), imaging receivers and delay adaptation techniques (DAT imaging LDs-VLC). However, higher data rates, beyond 10 Gb/s, are challenging due to the low signal to noise ratio (SNR) and inter symbol interference (ISI). In this paper, for the first time, to the best of our knowledge, we propose, design, and evaluate a VLC system that employs beam steering (of part of the VLC beam) using adaptive finite vocabulary of holograms in conjunction with an imaging receiver and a DAT to enhance SNR and to mitigate the impact of ISI at high data rates (20 Gb/s). An algorithm was used to estimate the receiver location, so that part of the white light can be directed towards a desired target (receiver) using beam steering to improve SNR. Simulation results of our location estimation algorithm (LEA) indicated that the required time to estimate the position of the VLC receiver is typically within 224 ms in our system and environment. A finite vocabulary of stored holograms is introduced to reduce the computation time required by LEA to identify the best location to steer the beam to the receiver location. The beam steering approach improved the SNR of the fully adaptive VLC system by 15 dB at high data rates (20 Gb/s) over the DAT imaging LDs-VLC system in the worst-case scenario. In addition, we examined our new proposed system in a very harsh environment with mobility. The results showed that our proposed VLC system has strong robustness against shadowing, signal blockage, and mobility.
关键词： imaging receiver,location estimation,delay adaptation,laser diodes,finite vocabulary of holograms,Beam steering,ISI,SNR
更新于2025-09-19 17:13:59