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[IEEE 2018 IEEE 38th International Electronics Manufacturing Technology Conference (IEMT) - Melaka (2018.9.4-2018.9.6)] 2018 IEEE 38th International Electronics Manufacturing Technology Conference (IEMT) - Implementation of PhotoMOS Relay for ATE Application
摘要： Globalization is the increasing interaction of people, states, or countries through the growth of the international flow of money, ideas, and culture. Thus, is create competition between semiconductor manufacturer to achieve low cost, high productivity, fast delivery and time to market are the vital factors to the success. Therefore, encouragement from manufacturer to looking for creative ideas with cost down reduction and high productivity [1]. Cost reduction covers a wide range such as package design optimization, process flow improvement and also testing which is the final gate before ship out the good and quality parts to customers. This paper provides the implementation of PhotoMOS relay to enhance the stability, sustainability and fastens the measurement in semiconductor automatic testing application. Relays are an essential part in semiconductor testing application and responsible as a switch to turn on and turn off the supply voltages or currents from tester instrument through test program control during testing to ensure functionality of electronic component meeting the specification before delivering to the consumer application. The relay functionality is sensitive especially in timing, resistances and frequency because it would influence the testing measurement results, induce instability of test program and result in unnecessary yield loss and capacity loss. However, this can be resolving through optimization test program. Nevertheless, there is a limitation of the mechanical relay which could not further or resolve through the test program. In this paper, an introduction of the PhotoMOS relays and differences as compared to mechanical relays (Pickering), experimental verification results in term of switching time, resistances of the relay and hot switch in Teradyne uFLEX tester platform for speed sensor devices.
关键词： Automatic test equipment,Photomos relay,Test program,Mechanical Relay,uFLEX tester
更新于2025-09-23 15:23:52
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Visible Light Driven Hydrogen Evolution by Molecular Nickel Catalysts with Time-Resolved Spectroscopic and DFT Insights
摘要： Hydrogen (H2) is a clean fuel that can potentially be a future solution for the storage of intermittent renewable energy. However, current H2 production is mainly dominated by the energy intensive steam reforming reaction, which consumes a fossil fuel, methane, and emits copious amounts of carbon dioxide as one of the byproducts. To address this challenge, we report a molecular catalyst that produces H2 from aqueous solutions, is composed of affordable, earth-abundant elements such as nickel, and has been incorporated into a system driven by visible light. Under optimized conditions, we observe a turnover number of 3880, among the best for photocatalytic H2 evolution with nickel complexes from water?methanol solutions. Through nanosecond transient absorption, electron paramagnetic resonance, and UV?vis spectroscopic measurements, and supported by density functional theory calculations, we report a detailed study of this photocatalytic H2 evolution cycle. We demonstrate that a one-electron reduced, predominantly ligand-centered, reactive Ni intermediate can be accessed under visible light irradiation using triethylamine as the sacrificial electron donor and reductive quencher of the initial photosensitizer excited state. In addition, the computational calculations suggest that the second coordination sphere ether arms can enhance the catalytic activity by promoting proton relay, similar to the mechanism among [FeFe] hydrogenases in nature. Our study can form the basis for future development of H2 evolution molecular catalysts that incorporate both ligand redox noninnocence and alternative second coordination sphere effects in artificial photosynthetic systems driven by visible light.
关键词： Proton relay,Second coordination sphere,DFT calculations,Time-resolved spectroscopy,Visible light photocatalysis,Hydrogen evolution,Molecular nickel catalysts
更新于2025-09-23 15:23:52
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Impact Analysis of DSSC on Distance Relay Performance under Fault Conditions
摘要： This paper demonstrates the impact analysis of the Distributed Static Series Compensator (DSSC), on the performance of distance relay protection of high voltage transmission lines. The concept of DSSC model with its control circuit and distance relay are described. A five bus test system with DSSC and distance relay is designed with the help of MATLAB/SIMULINK software. The impact of DSSC on distance protection relay for different fault conditions and various fault locations is analyzed. The results of simulation show that the connection of DSSC in the transmission system changes the transmission line impedance greatly as estimated by the distance relay to be less or greater than the actual impedance in fault conditions. Hence, the distance relay performance changes, either over reaches or under reaches.
关键词： FACTS Controller,Distributed FACTS Devices,Distributed Static Series Compensator,High Voltage Transmission Line,Distance Relay
更新于2025-09-23 15:22:29
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Distributed Processing for Multi-Relay Assisted OFDM with Index Modulation
摘要： Orthogonal frequency-division multiplexing with index modulation (OFDM-IM) has become a high-profile modulation scheme for the fifth generation (5G) wireless communications, and thus been extended to multi-hop scenarios in order to improve the network coverage and energy efficiency. However, the extension of OFDM-IM to multi-relay cooperative networks is not trivial, since it is required that a complete OFDM block should be received and decoded as an entity in one node. This requirement prevents the employment of multiple relays to forward fragmented OFDM blocks on individual subcarriers. In this regard, we propose a distributed processing scheme for multi-relay assisted OFDM-IM, by which multiple relays are selected to forward signals in a per-subcarrier manner to provide optimal error performance for two-hop decode-and-forward (DF) OFDM-IM systems. Specifically, a single selected relay only needs to decode partial information carried on certain active subcarriers and forward just as for traditional OFDM systems without IM. After receiving all signals on active subcarriers forwarded by different relays, the destination can reconstruct the complete OFDM block and retrieve the full information. We analyze the average block error rate (BLER) and modulation capacity of the two-hop OFDM-IM system employing the proposed distributed DF protocol and verify the analysis by numerical simulations.
关键词： multi-carrier relay selection,decode-and-forward (DF) relaying,Orthogonal frequency-division multiplexing with index modulation (OFDM-IM),distributed system,distributed processing
更新于2025-09-23 15:22:29
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Precise Performance Analysis of Dual-Hop Mixed RF/Unified-FSO DF Relaying with Heterodyne Detection and Two IM-DD Channel Models
摘要： This paper provides precise performance analysis of the dual-hop mixed radio frequency (RF)/unified free space optical (FSO) decode-and-forward (DF) relaying system, in which the heterodyne detection (HD) and the intensity modulation-direct detection (IM-DD) are taken into account for FSO detection. To this end, we derive closed-form expressions for the outage probability, average bit error rate (BER), and the ergodic channel capacity of this system. In this analysis, we utilize, for the first time as per our knowledge, a precise channel capacity result for the IM-DD channel. Moreover, this is the first time that not only the (IM-DD input-independent) but also the (IM-DD cost-dependent) AWGN channel is considered in such system analyses. Additionally in this study, we assume that the first hop (RF link) follows Nakagami-m fading, and the second hop (FSO link) follows Málaga (M) turbulence with pointing errors. These fading and turbulence models contain other models (such as Rayleigh and Gamma-Gamma) as special cases, thus our analyses can be seen as a generalized one from the RF and FSO fading models point of view. Also, in BER derivation, we assume that the modulation schemes in the two hops can be different, since not all modulation schemes are suitable for IM-DD FSO links. In addition, the system performance is investigated asymptotically at high signal to noise ratios (SNRs). This investigation leads to new non-reported coding gain and diversity order analyses of such system. Interestingly, we find that in the FSO hop, at high transmitted powers, all the considered FSO detectors result in the same diversity order. Furthermore, we provide simulation results that verify the accuracy of the obtained analytical and asymptotic expressions.
关键词： Nakagami-m fading,Málaga (M) fading,HD,DF,heterodyne detection,Mixed RF/FSO relay network,IM-DD,decode-and-forward,intensity modulation-direct detection
更新于2025-09-23 15:22:29
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Error rate and ergodic capacity of RF-FSO system with partial relay selection in the presence of pointing errors
摘要： This paper presents an analysis of a multiple dual-hop relaying system, which is composed of km-class radio frequency (RF)-free-space optical (FSO) links. Partial relay selection based on outdated channel state information (CSI) is employed in order to select active relay for further transmission. Amplify-and-forward relaying protocol is utilized. The RF links are assumed to be subject to Rayleigh fading, and the FSO links are influenced by both Gamma-Gamma atmospheric turbulence and pointing errors. On the basis of our previously derived expression for cumulative distribution function of the equivalent signal-to-noise ratio of the whole system, we derive novel analytical expressions for the average bit-error rate (BER) and ergodic capacity that are presented in terms of the Meijer’s G-function and extended generalized bivariate Meijer’s G-function, respectively. The numerical results are confirmed by Monte Carlo simulations. Considering the effect of time-correlation between outdated CSI and actual CSI related to the RF channel at the time of transmission, the average BER and the ergodic capacity dependence on various system and channel parameters are observed and discussed. The results illustrate that the temporal correlation between outdated and actual CSI has strong effect on system performance, particularly on BER values, when FSO hop is influenced by favorable conditions.
关键词： ergodic capacity,free-space optical systems,Bit error rate,partial relay selection,radio frequency systems.
更新于2025-09-23 15:22:29
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Outage and BER performances of indoor relay-assisted hybrid RF/VLC systems
摘要： In this study, the authors analyse the outage performance of the indoor relay-assisted hybrid radio frequency (RF)/visible light communication (VLC) systems. They derive closed-form expressions for the outage probability of the end-to-end signal-to-noise ratio. Then they obtain the optimal approximation parameter with optimising the outage probability using the differential evolution algorithm. Moreover, they analysed the average bit error rate (BER) performance of the hybrid RF/optical system using pulse position modulation method while assuming the timing error in synchronisation. Finally, they present some numerical results utilising the newly derived exact closed-form expressions.
关键词： pulse position modulation,hybrid RF/VLC,BER,differential evolution algorithm,relay-assisted,outage probability
更新于2025-09-23 15:21:21
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[IEEE 2019 Research, Invention, and Innovation Congress (RI2C) - Bangkok, Thailand (2019.12.11-2019.12.13)] 2019 Research, Invention, and Innovation Congress (RI2C) - Progress in a Development of a Laser-Based Weed Control System
摘要： In this correspondence, we investigate the performance of a multi-cell multiple-input multiple-output downlink (DL) system aided by base station (BS) cooperation, relay cooperation, and polarization-multiplexing (PM). Triply-polarized antennas that are employed at the BSs, relays, and mobile stations (MSs) to conceive PM serve as an replacement for multiple uni-polarized antennas that in?ict space limitation. In a multi-user multi-cell relay-aided scenario, MSs and relays con?ict multi-user interference (MUI) as well as inter-cell or co-channel interference (CCI). Furthermore, the MSs experience intra-relay interference and inter-relay interference. In this paper, both the MUI and CCI at the relays are completely removed by the combined preprocessing operated at the BS. Similarly, the intra-relay and inter-relay interference are eliminated with the aid of the joint preprocessing operated at the relays. Speci?cally, in this contribution, the performance of the considered system is investigated when the channel state information (CSI) required at the BSs to implement the joint preprocessing suffers from feedback and back-haul delays. In our contribution, feedback channels that convey the CSI to the BSs endure noise and fading as well. Our simulation study demonstrates that the use of triply polarized antennas in combination with joint preprocessing at the BSs and relays can be regarded as an ef?cient technique for the cooperative multi-cell DL system to deal with the space constraints and the aforementioned interferences. Furthermore, the considered preprocessing results in superior symbol-error-rate performance compared with other preprocessing approaches.
关键词： inter-relay interference,interference,Co-channel,MIMO,multi-user interference,intra-relay interference,polarization-multiplexing,noisy feedback
更新于2025-09-23 15:21:01
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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) - Reducing CPV Materials Cost Through Multistage Concentration
摘要： This paper considers an energy-limited cognitive relay network, where a secondary transmitter (ST) assists to forward the traf?c from a primary transmitter (PT) to a primary receiver (PR), in exchange for serving its own secondary receiver (SR) in the same frequency. The multiple-antenna ST is assumed to be energy-constrained and powered by both information ?ow from source (PT) and dedicated energy streams from destinations (PR and SR), which is called a destination-aided wireless power transfer (DWPT) scheme. Then, the relay processing matrix, cognitive beamforming vector, and power splitter are jointly designed to maximize the rate of secondary users under the energy causality constraint and the constraint that the demanded rate of primary users is satis?ed. For the perfect channel state information (CSI) case, by adopting the semi-de?nite relax technique and the Charnes–Cooper transformation, the global optimal solution is given. To reduce the complexity, matrix decomposition, zero forcing scheme, and dual method are jointly employed to derive a suboptimal solution. For the imperfect CSI case, the S-procedure is used to transform the worst case robust problem into a tractable semi-de?nite program. Simulation results reveal that our proposed DWPT scheme is greatly preferred for both perfect and imperfect CSI cases when ST is close to PR/SR.
关键词： cognitive relay networks,power splitting,Wireless power transfer,semi-de?nite program,beamforming design
更新于2025-09-23 15:21:01
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[IEEE 2019 SBFoton International Optics and Photonics Conference (SBFoton IOPC) - Sao Paulo, Brazil (2019.10.7-2019.10.9)] 2019 SBFoton International Optics and Photonics Conference (SBFoton IOPC) - Geometric Characterization of Conical Lensed Optical Fibers
摘要： We analyze the performance of an interference-limited decode-and-forward cooperative relaying system that comprises a source, a destination, and N relays, arbitrarily placed on the plane and suffering from interference by a set of interferers placed according to a spatial Poisson process. In each transmission attempt, first, the transmitter sends a packet; subsequently, a single one of the relays that received the packet correctly, if such a relay exists, retransmits it. We consider both selection combining and maximal ratio combining at the destination, Rayleigh fading, and interferer mobility. We derive expressions for the probability that a single transmission attempt is successful, as well as for the distribution of the transmission attempts until a packet is successfully transmitted. Results provide design guidelines applicable to a wide range of systems. Overall, the temporal and spatial characteristics of the interference play a significant role in shaping the system performance. Maximal ratio combining is only helpful when relays are close to the destination; in harsh environments, having many relays is particularly helpful, and relay placement is critical; the performance improves when interferer mobility increases; and a tradeoff exists between energy efficiency and throughput.
关键词： interference,relay networks,stochastic processes,Cooperative communication,wireless communication
更新于2025-09-23 15:21:01