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过滤筛选
- 2019
- 151 GHz transmitter/receiver
- PAM-4 modulation
- contactless communication
- plastic-embedded PCB
- digital pre-distortion
- plastic waveguide
- Electronic Science and Technology
- University of California, Los Angeles
- Taiwan Semiconductor Manufacturing Company
- U.S. Naval Research Laboratory
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A sensitive photochemical reaction-capacitively coupled contactless conductivity detection system for HPLC and its application in determination of Cyclosporin A
摘要： High performance liquid chromatography (HPLC) post-column photochemical reaction (PR) coupled capacitively coupled contactless conductivity detector (C4D) was used for the first time in analysis of weak ultraviolet (UV)-absorbing, non-fluorescence and nonpolar compound. A series of conditions including the radiation power of light source, the length of the reaction tube and the thickness of detection tube were investigated. HPLC-PR-C4D system was successfully applied to the determination of Cyclosporin A (CsA). Consequently, under optimal conditions, the detection system exhibited a detection limit of 0.04 μg/mL and wide linear range from 0.5 μg/mL to 100 μg/mL for CsA detection. Application of the HPLC-PR- C4D system to pharmaceutical formulation and biological samples revealed the system developed maybe reliably applied to clinical studies.
关键词： Photochemical reaction,Cyclosporin A,HPLC,Capacitively coupled contactless conductivity detection,Application
更新于2025-09-11 14:15:04
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Ferroelectric‐Polymer‐Enabled Contactless Electric Power Generation in Triboelectric Nanogenerators
摘要： Triboelectric nanogenerators (TENGs) are considered as one of the most important renewable power sources for mobile electronic devices and various sensors in the Internet of Things era. However, their performance should inherently be degraded by the wearing of contact surfaces after long-term use. Here, a ferroelectric polymer is shown to enable TENGs to generate considerable electricity without contact. Ferroelectric-polymer-embedded TENG (FE-TENG) consists of indium tin oxide (ITO) electrodes, a polydimethylsiloxane (PDMS) elastomer, and a poly(vinylidene fluoride) (PVDF) polymer. In contrast to down- and non-polarization, up-polarized PVDF causes significantly large triboelectric charge, rapidly saturated voltage/current, and considerable remaining charge due to the modulated surface potential and increased capacitance. The remained triboelectric charges flow by just approaching/receding the ITO electrode to/from the PDMS without contact, which is sufficient to power light-emitting diodes and liquid crystal displays. Additionally, the FE-TENG can charge an Li-battery with a significantly reduced number of contact cycles. Furthermore, an arch-shaped FE-TENG is demonstrated to operate a wireless temperature sensor network by scavenging the irregular and random vibrations of water waves. This work provides an innovative and simple method to increase conversion efficiency and lifetime of TENGs; which widens the applications of TENG to inaccessible areas like the ocean.
关键词： contactless power generation,surface potential,capacitance,ferroelectric polymers,triboelectric nanogenerators
更新于2025-09-11 14:15:04
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[IEEE 2019 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting - Atlanta, GA, USA (2019.7.7-2019.7.12)] 2019 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting - Performance Comparison of Silicon Substrates for IC-Waveguide Integration based on a Contactless Transition at mm-Wave frequencies
摘要： This paper presents a comparison between different silicon (Si) substrates used in Si-based IC technologies at E-Band (71–86 GHz). A unique low-loss and compact contactless transition from a silicon IC (p-doped substrate) to a metal waveguide is used. The proposed transition incorporates a spatial power combiner to enable direct electromagnetic coupling from an array of patches on the IC to a metal waveguide. This design enables a high-power transition from an IC to a waveguide and/or antenna at millimeter-wave (mm-wave) frequencies, where a galvanic contact between the two parts is avoided.
关键词： IC-waveguide integration,millimeter-wave frequencies,contactless transition,silicon substrates,spatial power combiner
更新于2025-09-11 14:15:04
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Masked SIFT with Align-Based Refinement for Contactless Palmprint Recognition
摘要： Contactless palmprint is considered more user convenient than other biometrics due to its acquisition simplicity and less-private nature. Many challenges arise which affect the performance of common contact-based methods when applied to contactless environment. For example, pose and illumination variations affect the layout and visibility of palm lines. This paper proposes a SIFT-based method with three main modifications from the traditional SIFT. First, the palm regions with no significant lines/wrinkles are masked out to reduce the false features. A region with multi lines are then described by multi descriptors rather than a single one. Second, instead of comparing all query keypoints with all target ones, only those with small rotation difference are matched together. This speed-up the comparison process and enhance the accuracy, compared with SIFT, by reducing the wrong matches. Third, an align-based refinement is applied to filter out the incorrect matches. The method is tested on three contactless hand databases; IITD, GPDS and Sfax-Miracl. It achieves a verification equal error rate of 0.72%, 0.84% and 1.14% and a correct identification rate of 98.9%, 99% and 98.9% on each database, respectively. These results are significantly better than the state-of-art methods on same databases by 1.9% for verification and 3.2% for identification.
关键词： SIFT,Contactless palmprint,Biometrics,MaskedSIFT,Align-Based Refinement,Selective Matching
更新于2025-09-10 09:29:36
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A Smart Autonomous WPT System for Electric Wheelchair Applications with Free-Positioning Charging Feature
摘要： Electric Wheelchairs (EWs) are gradually replacing conventional wheelchairs as an assistive tool for people with disabilities who are unable to use physical force to drive manual wheelchairs on their own. EW charging requires manipulating, plugging in, and unplugging an off-board charger, which can be challenging or impossible for people with severe disabilities. In this paper, a comprehensive solution to the problem of EW recharging is provided in the form of a smart, autonomous charging system, based on Wireless Power Transfer (WPT) technology. In this research, a sufficiently large area of 0.75 m2 for a floor-charging pad involving multiple primary coils has been implemented while offering a free-positioning charging feature. A novel design methodology for primary and secondary charging pads optimization has been developed, taking into account various complex real-life constraints. In addition, a novel 250-W WPT controller design has been employed to maximize misalignment tolerance up to 7 cm while maintaining high system efficiency. In this paper, a novel, comprehensive, system-level organization of a master controller design has been presented which manages continuous coordination between the WPT controllers and the autonomous docking controller, records important system data, maintains safe operation of overall system, and prevents hazardous exposure to potentially harmful magnetic field beyond 15 μT. Additionally, a novel design methodology for primary and secondary charging pads optimization has been developed, that takes into account various real-life constraints, and provides a fair comparison between different designs in a multivariable environment. The proposed design is tested in laboratory conditions and later validated in a practical environment.
关键词： ground robotics,free positioning,Dynamic contactless battery charging,electric wheelchair,wireless power transfer,stationary charging,assistive autonomy
更新于2025-09-09 09:28:46
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Contactless Liquid Interface Measurement based on a Hollow Coaxial Cable Resonator
摘要： This paper reports a contactless liquid interface sensor based on a microwave Fabry-Perot resonator. A hollow coaxial cable is employed as the sensing platform, in which air serves as the dielectric layer. By shorting the inner and outer conductors of the hollow coaxial cable, two reflectors with high reflectivity (> 70%) are created to form a microwave Fabry-Perot resonator. An open groove is engineered on the resonator allowing the electromagnetic wave to interact with the medium outside the cavity. When a container, filled with different layers of liquids, is placed near the groove edge of the sensor, the leaked electromagnetic wave will interact with the liquids inside the container. By correlating the relative permittivity of the liquid mixture to the resonant frequency of the Fabry-Perot resonator, the interface between different liquids can be unambiguously determined. In the demonstration experiment, the water-oil interface and oil-ethanol interface were measured. Meanwhile, the sensor could also be employed to measure the relative permittivity of different liquids in a non-contact fashion. The presented sensor offers a robust, cost-effective, and real-time configuration for contactless liquid interface detection, which has potential applications in the oil and chemical industries.
关键词： hollow coaxial cable,Fabry-Perot resonator,Liquid interface,contactless measurement
更新于2025-09-04 15:30:14
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[IEEE 2018 IEEE International Symposium on the Physical and Failure Analysis of Integrated Circuits (IPFA) - Singapore (2018.7.16-2018.7.19)] 2018 IEEE International Symposium on the Physical and Failure Analysis of Integrated Circuits (IPFA) - Characterization of Bandgap Engineering on Operative Transistor Devices by Spectral Photon Emission
摘要： In modern IC technologies, it is very common to use germanium enriched silicon in order to increase field effect transistor (FET) channel carrier mobility for high performance. The germanium content modifies the effective semiconductor band gap EG. Thus, the bandgap energy EG is an important technology performance parameter. EG can be obtained in an LED-like operation of electronic devices, requiring forward biased p-n junctions. P-n junctions in FETs are source or drain to body diodes, usually grounded or reversely biased. This investigation applies a bias to the body that can trigger parasitic forward operation of the source/drain to body p-n junction in any FET. Spectral photon emission (SPE) is taken here as non-destructive in operative method to characterize engineered bandgaps transistor devices, while the device remains fully functional. Proving this technique with the nominal silicon bandgap on an (unstrained) 120nm technology FET, the characterization capability for bandgap engineering is successfully demonstrated using SiGe:C HBT. In IC technology, Ge enriched silicon is recently often used to increase channel carrier mobility. As a next step, 14/16nm p-type FinFET devices have been investigated by applying a bias voltage to the body and thereby activating one of the body/diffusion p-n junctions in forward bias. By measuring the spectral distribution of emission intensity through the backside of the operating device with an InGaAs detector, EG of the engineered bandgap can be determined in the FinFETs as well, in case of the investigated p-type FinFETs to 0.84 eV. This opens a new path for contactless fault isolation by quantitative local determination of bandgap engineering.
关键词： Bandgap engineering,body diode,heterojunction bipolar transistor,body bias voltage,contactless fault isolation,parasitic operation,FinFET,germanium,MOSFET,p-n junction,bandgap characterization,spectral photon emission,SiGe,HBT
更新于2025-09-04 15:30:14
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Holographic acoustic tweezers
摘要： Acoustic tweezers use sound radiation forces to manipulate matter without contact. They provide unique characteristics compared with the more established optical tweezers, such as higher trapping forces per unit input power and the ability to manipulate objects from the micrometer to the centimeter scale. They also enable the trapping of a wide range of sample materials in various media. A dramatic advancement in optical tweezers was the development of holographic optical tweezers (HOT) which enabled the independent manipulation of multiple particles leading to applications such as the assembly of 3D microstructures and the probing of soft matter. Now, 20 years after the development of HOT, we present the realization of holographic acoustic tweezers (HAT). We experimentally demonstrate a 40-kHz airborne HAT system implemented using two 256-emitter phased arrays and manipulate individually up to 25 millimetric particles simultaneously. We show that the maximum trapping forces are achieved once the emitting array satisfies Nyquist sampling and an emission phase discretization below π/8 radians. When considered on the scale of a wavelength, HAT provides similar manipulation capabilities as HOT while retaining its unique characteristics. The examples shown here suggest the future use of HAT for novel forms of displays in which the objects are made of physical levitating voxels, assembly processes in the micrometer and millimetric scale, as well as positioning and orientation of multiple objects which could lead to biomedical applications.
关键词： acoustic levitation,acoustophoresis,acoustic tweezers,contactless manipulation,displays
更新于2025-09-04 15:30:14
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A Compact Contactless Coaxial VHF Rotary Joint for Surveillance Radar
摘要： A new design of coaxial rotary joint (RJ) made compact by applying “folded” choke quarter-wave impedance transformer is proposed for very high-frequency surveillance radar. The ?nal prototype, which measures L 388 mm × D 106 mm, demonstrated 0.04-dB insertion loss and 28-dB return loss within the operating frequency range of 150–170 MHz. The RJ is able to handle peak power of 15 kW during experiments. By avoiding reliability issues inherent in contacting RJ, the life-time and stability of the whole radar system would be remarkably enhanced.
关键词： radar,quarter-wave choke,very high frequency (VHF),Contactless,rotary joint (RJ),low VSWR
更新于2025-09-04 15:30:14