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oe1(光电查) - 科学论文

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出版时间
  • 2018
研究主题
  • filtering responses
  • compact size
  • substrate integrated waveguide (SIW)
  • Balun and balanced circuits
应用领域
  • Electronic Science and Technology
机构单位
  • South China University of Technology
41 条数据
?? 中文（中国） ▾

  • Application of blurred circular 3D images on the human vision model

    摘要： By letting students simulate operations and games on a digital education operation system, schools are able to inspect learning achievement and teaching quality. In digital education area, we are able to use blockchain technology to simplify process, improve competition mode. It’s helpful improve efficiency and avoid the problem of opaque and falsification messages. Besides, it can provide unchangeable digital certification of academic achievement. Based on existing research foundation, against features on related users and services, especially the standard and trustful problem in competitions and evaluation mode nowadays, I studied competition mode based on blockchain technology, designed blockchain’s application mode and frame, analyzed evaluation criteria and algorithm, designed an operational skill evaluation model, developed an operational skill competition evaluation system based on e-business sandbox and experimented it.

    关键词： digital education,evaluation model,blockchain,operational skill competition,fuzzy AHP,balanced score card

    更新于2025-09-23 15:23:52

  • Compact Dual-Channel Balanced Filter and Balun Filter Based on Quad-Mode Dielectric Resonator

    摘要： In this paper, we propose a method for designing a dual-channel balanced filter and a dual-channel balun filter based on the quad-mode dielectric resonator (DR) for the first time. By sharing one common quad-mode DR, two balanced filters or two balun filters are integrated as one single-cavity configuration, featuring compact size and high integration. A cylindrical DR with two short ends is investigated to construct the quad-mode DR. By properly arranging input and output feeding probes, two modes of the DR are only excited by the feeding probes of one channel and the other two modes are excited by that of the other channel. Accordingly, signals cannot be transmitted between the two channels, resulting in high isolation. Moreover, the required out-of-phase characteristics of the balanced and balun filters can be obtained by the inherent electromagnetic field properties of the DR without adding additional circuits, featuring a simple structure. For demonstration, a dual-channel balanced filter and a dual-channel balun filter are designed and fabricated, showing excellent balanced or balun filter performance of each channel as well as high isolation between the two channels. As compared to the other reported DR balanced and balun filters, the proposed designs exhibit a significant size reduction, which are attractive in wireless systems.

    关键词： Balanced filter,high Q factor,dielectric resonator (DR),balun filter,MIMO,size reduction,dual-channel

    更新于2025-09-23 15:23:52

  • [IEEE 2018 International Conference on Radar (RADAR) - Brisbane, Australia (2018.8.27-2018.8.31)] 2018 International Conference on Radar (RADAR) - Improved Tx-to-Rx Isolation of Radar Transceivers Using Integrated Full Duplexer with PLL

    摘要： The isolation between transmitter and receiver for the radars is ultimately important since the transmitting radar signals can be penetrated the receiver directly in case a bad isolation is formed. This paper describes the isolation between the transceiver and the design of an integrated full duplexer using the phase locked loop (PLL). Although the antenna impedance varies arbitrarily, the PLL tracks the impedance variation in real time, leading to improvement of isolation between the transmitter and the receiver of radars. The full duplexer reduces the transmitter leakage up to 45 dB using the balance network along with the PLL in measurement.

    关键词： Transceiver,Impedance tracking,PLL,Balanced network,CMOS process,Integrated Full Duplexer

    更新于2025-09-23 15:22:29

  • On the Possibility of Breaking the Heterodyne Detection Quantum Noise Limit With Cross-Correlation

    摘要： The cross-correlation sensitivity of two identical balanced photodiode heterodyne receivers is characterized. Both the balanced photodiodes receive the same weak signal split up equally, a situation equivalent to an astronomical spatial interferometer. A common local oscillator is also split up equally and its phase difference between both the receivers is stabilized. We show by a semi-classical photon deletion theory that the post-detection laser shot noise contributions on both the receivers must be completely uncorrelated in this case of passing three power splitters. We measured the auto- and cross-correlation outputs as a function of the weak signal power (system noise temperature measurement) and obtained a cross-correlation system noise temperature up to 20 times lower than for the auto-correlation system noise temperature of each receiver separately. This is supported by Allan plot measurements showing cross-correlation standard deviations 30 times lower than in auto-correlation. Careful calibration of the source power shows that the auto-correlation (regular) noise temperature of the single balanced receivers is already very near to the quantum limit as expected, which suggests a cross-correlation system noise temperature below the quantum limit. If validated further, this experimentally clear finding will not only be relevant for astronomical instrumentation but also for other fields, such as telecommunications and medical imaging.

    关键词： Heterodyne receiver,noise temperature,quantum limit,auto-correlation,cross-correlation,balanced receiver,noise cancellation

    更新于2025-09-23 15:22:29

  • [ASME ASME 2015 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference - Boston, Massachusetts, USA (Sunday 2 August 2015)] Volume 8: 27th Conference on Mechanical Vibration and Noise - Nonlinear Free Vibration of Piezoelectric Functionally Graded Beams in Thermal Environment

    摘要： Nonlinear free vibration analysis of piezoelectric functionally graded (PFG) beams in thermal environment with any boundary conditions are investigated. The nonlinear governing Equation of motion is derived based on the Euler-Bernoulli beam theory and Von Karman's strain-displacement relation. Simple analytical expression is presented for the nonlinear natural frequency using energy balanced method (EBM). Results are validated and compared with available results in the literature. Effects of different parameters such as vibration amplitude, boundary conditions, material inhomogenity, electrical and thermal loading on the nonlinear behavior of PFG beams are presented.

    关键词： Boundary conditions,Energy balanced method,Piezoelectric functionally graded beams,Nonlinear free vibration,Thermal environment

    更新于2025-09-23 15:22:29

  • A New, Specular Reflection-Based, Precorneal Tear Film Stability Measurement Technique in a Rabbit Model: Viscoelastic Increases Tear Film Stability

    摘要： PURPOSE. To develop a safe, noninvasive, noncontact, continuous in vivo method to measure the dehydration rate of the precorneal tear film and to compare the effectiveness of a viscoelastic agent in maintaining the precorneal tear film to that of a balanced salt solution. METHODS. Software was designed to analyze the corneal reflection produced by the operating microscope’s coaxial illumination. The software characterized the shape of the reflection, which became distorted as the precorneal tear film evaporated; characterization was accomplished by fitting an ellipse to the reflection and measuring its projected surface area. Balanced salt solution Plus (BSS+) and a 2% hydroxypropylmethylcellulose viscoelastic were used as the test agents. The tear film evaporation rate was characterized and compared over a period of 20 minutes in 20 eyes from 10 New Zealand white rabbits. RESULTS. The ellipse axes ratio and surface area were found to decrease initially after each application of either viscoelastic or BSS+ and then to increase linearly as the tear film began to evaporate (P < 0.001) for eyes treated with BSS+ only. Eyes treated with BSS+ required 7.5 ± 2.7 applications to maintain sufficient corneal hydration during the 20-minute test period, whereas eyes treated with viscoelastic required 1.4 ± 0.5 applications. The rates of evaporation differed significantly (P < 0.043) between viscoelastic and BSS+. CONCLUSIONS. The shape and surface area of the corneal reflection are strongly correlated with the state of the tear film. Rabbits’ corneas treated with viscoelastic remained hydrated significantly longer than corneas treated with BSS+.

    关键词： evaporation,corneal hydration,precorneal tear film stability,viscoelastic,balanced salt solution

    更新于2025-09-23 15:22:29

  • Ternary Organic Solar Cells Based on two Non-fullerene Acceptors with Complimentary Absorption and Balanced Crystallinity

    摘要： The ternary blend structure has been demonstrated as an effective approach to increase the power conversion efficiency of organic solar cells. An effective approach to enhance the power conversion efficiency of ternary solar cells is based on two non-fullerene acceptors with complimentary absorption range and balanced crystalinity. In this work, by introducing a high crystallinity small-molecule acceptor, named C8IDTT-4Cl with appropriate alkyl side chains into a low crystalline blend of conjugated polymer donor PBDT-TPD and fused-ring electron acceptor ITIC-4F. A ternary device based on the blend PBDT-TPD:ITIC-4F:C8IDTT-4Cl exhibits a best power conversion efficiency of 9.51% with a simultaneous improvement of the short-circuit current density to 18.76 mA cm-2 and the fill factor up to 67.53%. The absorption onset for C8IDTT-4Cl is located at 900 nm, so that the well complementary light absorption is beneficial to the photocurrent. In addition, the existence of high crystallinity C8IDTT-4Cl in the ternary device is found helpful to modulate crystallinity, improve heterojunction morphologies and stacking structure, therefore to realize higher charge mobility and better performance.

    关键词： Non-fullerene Acceptors,Ternary Organic Solar Cells,Power Conversion Efficiency,Complimentary Absorption,Balanced Crystallinity

    更新于2025-09-23 15:21:01

  • Improved-efficiency quasi-two-stage current-source-mode SIMO LED driver

    摘要： The paper presents a modularized control strategy of doubly fed induction generator (DFIG) system, including the grid-side converter (GSC) and rotor-side converter (RSC), under unbalanced and harmonic grid voltage. The sequence decomposition process and complicated control reference calculation can be avoided in the proposed control strategy. From the perspective of power grid friendly operation, the control targets of DFIG system in this paper are chosen as: 1) smooth active and reactive power injected into the power grid; 2) balanced and sinusoidal current injected into the power grid. The RSC and GSC can work as two independent modules and the communication between RSC and GSC can be removed. Furthermore, the third harmonic current component, dc-link voltage fluctuation, and electromagnetic torque pulsation under the different control targets are theoretically analyzed. Finally, the availability of the proposed modularized control strategy of DFIG system under unbalanced and distorted grid voltage is verified by experiment results.

    关键词： unbalanced and harmonic grid voltage,modularized control,doubly fed induction generator (DFIG) system,smooth active and reactive power,Balanced and sinusoidal current

    更新于2025-09-23 15:21:01

  • Single-Layer Dual-Band Balanced Substrate- Integrated Waveguide Filtering Power Divider for 5G Millimeter-Wave Applications

    摘要： A single-layer substrate-integrated waveguide (SIW) filtering power divider (FPD) with fully differential operation at 28 and 39 GHz is proposed in this letter. This FPD consists of three SIW cavities where the differential and common modes of each cavity were properly designed to form three-pole dual passbands, facilitate deployment of isolation resistors, and introduce transmission zeros while attaining high in-band common-mode rejection. To improve the output return loss and isolation in dual bands, a novel and simple approach to find the proper location of isolation resistors is presented. At operating frequencies, the measured differential-mode input or output return loss, minimum insertion loss, isolation, and common-mode suppression are >14.1 dB, <(3 + 2.2) dB, >14.9 dB, and >30.3 dB, respectively. The amplitude and phase imbalances between outputs are <0.48 dB and <4.2?, respectively.

    关键词： balanced,dual-band,isolation resistor,common-mode rejection,substrate-integrated waveguide (SIW),differential,single-layer,mixed-mode,filtering power divider (FPD),5G

    更新于2025-09-23 15:21:01

  • [IEEE 2019 IEEE 26th International Symposium on the Physical and Failure Analysis of Integrated Circuits (IPFA) - Hangzhou, China (2019.7.2-2019.7.5)] 2019 IEEE 26th International Symposium on Physical and Failure Analysis of Integrated Circuits (IPFA) - Optical Failure Analysis on Pulsed Signals Embedded in Logic Cloud a?? A Case Study of Laser Voltage Tracing

    摘要： A key problem in wireless mesh networks is forwarding packets to/from one or more gateways with connectivity to the Internet. In this respect, a short link schedule, which determines the transmission time of links, is critical. To date, existing link schedulers do not consider routers that incorporate advances in multiple input multiple output communications, i.e., interference cancellation and spatial multiplexing. In particular, these routers are able to transmit or receive distinct packets on all their links concurrently as well as deliver multiple packets to a neighbor simultaneously. To this end, we consider the problem of deriving a time division multiple access schedule that forwards packets to their respective destination quickly. We ?rst consider the personalized broadcast problem, which assumes a single gateway and present Algo-PB, a solution that produces a schedule that is within 34.5% of the lower bound, and is 45.5% shorter than those computed by the state-of-the-art algorithms. We then extend the problem to consider multiple gateways. This so-called forest construction problem is modeled as an integer linear program (ILP). We then outline Algo-FC, a novel heuristic that generates a balanced forest by repeatedly picking a node from the heaviest tree and migrating it to another tree if doing so reduces the overall load. Experiment results show that the resulting forest generated by Algo-FC is within 9.1% of the ILP solution.

    关键词： Link scheduler,multiple gateways,balanced tree,NP-complete,integer linear program (ILP)

    更新于2025-09-23 15:21:01