- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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An On-Chip Monitoring Circuit with 51-Phase PLL-Based Frequency Synthesizer for 8-Gb/s ODR Single-Ended Signaling Integrity Analysis
摘要： An on-chip monitoring circuit using a sub-sampling scheme, which consists of a 6-bit flash analog-to-digital converter (ADC) and a 51-phase phase-locked loop (PLL)-based frequency synthesizer, is proposed to analyze the signal integrity of a single-ended 8-Gb/s octal data rate (ODR) chip-to-chip interface with a source synchronous clocking scheme.
关键词： on-chip monitoring circuit,sub-sampling,chip-to-chip interface,analog-to-digital converter,phase-locked loop-based frequency synthesizer
更新于2025-09-23 15:22:29
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Modeling the Effect of Wavelength Selective Switch Latency on Optical Flow Switching Performance
摘要： Optical networks are well suited to enable massive data exchanges between datacenters. Elephant data flows can be routed over custom provisioned and dedicated lightpaths (optical flows) while other (mice) flows, which are routed by electronic switches, are unaffected. In some solutions, wavelength-selective switch (WSS) devices are employed in the optical nodes to physically and individually route each lightpath toward its destination. WSS devices take time to be switched and consequently delay the lightpath setup completion time. In this paper, the authors present three approximate Markov chain models to account for three different WSS service policies. These models estimate the expected lightpath setup and teardown time across an optical node that makes use of WSS devices. The first and more conventional policy (model) assumes that each setup and teardown request is handled individually, while the other two policies (models) assume that groups of setup and/or teardown requests are handled together by the WSS. The models’ estimates are compared against the results obtained from a computer-based simulator, where both analytical models and simulator account for experimentally measured WSS response times. The simulator is also used to investigate the end-to-end lightpath setup time across an arbitrary mesh network. Results obtained from the models and simulator show that the group-based service policies outperform the conventional policy at high loads. The group-based policies are especially useful in the presence of lightpaths that are frequently set up and have relatively short holding time (i.e., short duration of elephant-optical flows).
关键词： Circuit switching,Markov chain model,Optical networks,Wavelength selective switch
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP) - Auckland (2018.8.5-2018.8.8)] 2018 IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP) - Maximum efficiency analysis in wireless power transfer
摘要： The optimum design of loosely coupled transformer is the key technique in the wireless power transfer system (WPT). An improved magnetic model based on partial element equivalent circuit (PEEC) method is proposed in this paper. All parts of magnetic flux are divided into four categories: 1) flyback to topology; 2) resonant to topology; 3) quasi-resonant to topology; and 4) self-resonant to topology. As becomes clear from previous discussion, the converter topology used must be able to tolerate the minimum copper loss and minimum number of turns in given power transformer capability. In this method, the preferred parameters are coil shape and dimension, operating frequency, and coupling coefficient. The validity of the optimization algorithm is verified by experimental results.
关键词： reluctance model,parameter optimization,partial element equivalent circuit method,wireless power transfer,Prime-Mal
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE Power & Energy Society General Meeting (PESGM) - Portland, OR, USA (2018.8.5-2018.8.10)] 2018 IEEE Power & Energy Society General Meeting (PESGM) - Study of Impact of Cloud Distribution on Multiple Interconnected Solar PV Plants Generation and System Strength
摘要： Dependence of solar power generation on solar irradiance results in sudden and dramatic variations in power generation following significant changes in cloud distribution over a solar PV plant. Currently, this phenomenon is being one of the most challenging issues in resource planning and maintaining the reliability of modern power grids with high penetration of solar power. The dramatic variation of solar power generation has a direct impact on system strength at the Points of Interconnection (POIs). Hence, the power quality of the system is compromised, especially because solar PV plants are usually interconnected to distribution systems and near load zones. In this paper, an Artificial Neural Network (ANN) based approach is developed to forecast the clouds distribution for the estimation of sudden and dramatic variations in the solar irradiance. This estimate is used to evaluate the system strength in terms of voltage stability at each POI. We apply newly developed methodology to measure the system strength known as Site-Dependent Short Circuit Ratio (SDSCR), which provides more accurate results of system strength evaluation. The validity and effectiveness of the developed approach is confirmed through comparing its results versus the cloud distribution data provided by weather satellites.
关键词： Artificial neural network,renewable energy,system strength,voltage stability,short circuit ratio
更新于2025-09-23 15:22:29
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Design and Evaluation of Optical Circuit Switches for Intra-Datacenter Networking
摘要： With the rapid growth in intra-datacenter traffic, the high power consumption stemming from the huge number of electrical switches is becoming a critical issue. Hence, high-port-count optical circuit switches are urgently needed. In this paper, we overview recently developed optical circuit switch architecture based on two-dimensional switches, i.e., space switches and wavelength-routing switches. The attainable maximum switch port counts and hardware requirements are quantitatively evaluated through extensive computer simulations that consider 10-Gbps intensity modulation with direct detection systems, 43-Gbps differential quadrature phase shift keying with self-coherent detection systems, and 128-Gbps dual-polarization quadrature phase shift keying with coherent detection systems. The simulation results confirm the existence of switching architecture that can accommodate more than 1,000 ports with relatively light hardware requirements.
关键词： wavelength routing,optical circuit switch,Datacenter network
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE MTT-S International Conference on Numerical Electromagnetic and Multiphysics Modeling and Optimization (NEMO) - Reykjavik, Iceland (2018.8.8-2018.8.10)] 2018 IEEE MTT-S International Conference on Numerical Electromagnetic and Multiphysics Modeling and Optimization (NEMO) - Low-Cost Simulation-Driven Design of Broadband Rectifiers for Ambient RF Energy Harvesting
摘要： A steady growth of ambient RF energy density associated with a rapid increase of the number of broadcasting devices stimulates the research on broadband harvesting circuits. Such circuits can be used as energy sources for low-power sensors or Internet-of-Things devices. On the other hand, dedicated design techniques for rectifiers are lacking which results in poor performance of existing circuits. Also, their design cost is high because it involves hybrid electromagnetic (EM) and harmonic balance (HB) simulations. In this work, we propose a novel design procedure for low-cost design of broadband rectifiers. The core component of the approach is a novel equivalent-circuit-based low-fidelity model which does not involve harmonic balance (HB) simulations. The model consists of a matching circuit loaded with the RF-to-DC converter block represented using the S-parameter matrix. The latter is obtained from a single HB simulation of the converter circuit. Inaccuracy of the model is reduced using appropriate correction techniques. At the first stage of the design process, the proposed model is optimized for minimization of the in-band reflection. At the second stage, a hybrid HB-EM-based tuning oriented towards maximization of the structure efficiency is carried out. The proposed approach is demonstrated using a novel broadband rectifier operating within 0.5 GHz to 3.5 GHz band. Numerical cost of the method is 80% lower compared to direct EM-HB- based optimization of the rectifier circuit.
关键词： broadband rectifiers,constrained optimization,simulation-driven design,surrogate-based optimization,equivalent circuit model
更新于2025-09-23 15:21:21
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[IEEE 2018 IEEE PES/IAS PowerAfrica - Cape Town, South Africa (2018.6.28-2018.6.29)] 2018 IEEE PES/IAS PowerAfrica - Efficient Energy Management System Using Pir Sensor
摘要： In most developing countries like Nigeria, the demand for electrical energy outweighs the supply. Negative economic and environmental impacts are also associated with its generation, transmission, and consumption. As a result there is need for the available energy to be efficiently managed. This project designed and implemented a microcontroller based energy saver and management system. The design of the energy saver and management system was aimed at coordinating the manner of use of electrical appliances, thereby reducing energy consumption in electrical appliances (such as fan and light) and devising a means of reducing the need for human intervention in the control of electrical appliances in a residential building. The project consists of a PIC microcontroller that utilizes a PIR sensor to detect occupants’ presence in the building; it also has a light intensity detection unit used to determine the level of ambient lighting as well as a temperature sensor to determine ambient temperature. The control signal from the microcontroller was used to operate the load driver circuit to switch the appliances on or off. The results show that the designed system can reduce the level of energy consumption effectively and efficiently.
关键词： load driver circuit,appliances,temperature sensor,light intensity detection,PIC microcontroller,Energy saver and Management system
更新于2025-09-23 15:21:21
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Design of a Compact GaN MMIC Doherty Power Amplifier and System Level Analysis With X-Parameters for 5G Communications
摘要： This paper presents a monolithic microwave integrated circuit Doherty power amplifier (DPA) operating at sub-6 GHz for 5G communication applications by a 0.25-μm gallium nitride high-electron mobility transistor process. A compact impedance inverter and output matching of the DPA are achieved using a transmission line network and shunt capacitors. Also, the size ratio of power cells in the main and auxiliary amplifiers is optimized for a high efficiency at output power backoff (OPBO). The measured peak output power (Pout) and the 1-dB compression point (P1 dB) are 38.7 and 32.1 dBm, respectively, at 5.9 GHz. The power-added efficiency at 6-dB OPBO is up to 49.5%. Without digital predistortion (DPD), the DPA can deliver an average Pout of 23.5 dBm with error vector magnitude (EVM) <?28 dB and 21.5 dBm with EVM <?32 dB for 64-quadrature amplitude modulation (QAM) and 256-QAM signals, respectively. The measured X-parameters are employed to further investigate the DPA nonlinear characteristics and verify the accuracy of conventionally used power amplifier characterization/measurement methods for system-level design and testing applications. The simulated results based on the X-parameters also indicate that the average output power can be enhanced up to 25.7 dBm with DPD for 256-QAM.
关键词： 5G communication,monolithic microwave integrated circuit (MMIC),X-parameters,power-added efficiency (PAE),power amplifier (PA),Doherty,gallium nitride (GaN)
更新于2025-09-23 15:21:21
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An Optically Transparent Broadband Microwave Absorber using Interdigital Capacitance
摘要： In this paper, an optically transparent broadband microwave absorber has been developed. The proposed geometry is constructed of patterned resistive films of ITO on flexible substrates, structure exhibits broadband absorptivity (above 90%) from 4 to 17.20 GHz (covering C, X, and Ku bands). The novelty of the design lies in leveraging the properties of interdigital capacitance to achieve wide absorption (fractional bandwidth of 124.53%), angular stability, as well as optical transparency compared to the earlier reported broadband absorbers. Moreover, the structure has been extensively investigated through deriving an equivalent circuit model and studying surface current distributions. Experimental validation of the fabricated prototype has also confirmed the potential use of resistive film based broadband absorbers in several applications.
关键词： interdigital capacitance,optically transparent absorber,Circuit analog absorber,broadband absorber
更新于2025-09-23 15:21:21
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Miniaturized Planar Sensor Development
摘要： This paper describes the process of developing a miniature device with planar sensors utilizing electrical capacitance measurement. The project investigates the feasibility and characterization of a miniaturized planar sensor integrated on a polydimethylsiloxane (PDMS) chamber. A 16-planar-electrodes array, with each dimension of the electrode, 4 mm × 2 mm (length × width) was fabricated using a printed circuit board (PCB) technology due to its low cost advantage. The measurement chamber for the sensing area was fabricated using PDMS. The PDMS chamber was bonded on the PCB with a semi cured PDMS to create a round sensing area for sample loading. The mould to develop the PDMS chamber was designed using AutoCAD 2010 and was fabricated using a 3D printer. Capacitance measurement of the planar electrodes was carried out using water as the sample and was validated using a theoretical calculation. Experimental result shows that the distance of the measured electrodes is inversely proportional to the capacitance value. The range of the measured capacitances of the measurement varies from 10 pF to 20 pF. The result shows that the planar sensors are able to provide capacitance measurement within the miniaturized platform where the measured capacitance showed good agreement with the theoretical calculation.
关键词： printed circuit board (PCB),Planar sensors,capacitance measurement,polydimethylsiloxane (PDMS)
更新于2025-09-23 15:21:21