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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) - Optimization Methods for Evaluating PV Hosting Capacity of Distribution Circuits
摘要： We propose a new transmitter architecture for ultra-low power radios in which the most energy-hungry RF circuits operate at a supply just above a threshold voltage of CMOS transistors. An all-digital PLL employs a digitally controlled oscillator with switching current sources to reduce supply voltage and power without sacrificing its startup margin. It also reduces 1/f noise and supply pushing, thus allowing the ADPLL, after settling, to reduce its sampling rate or shut it off entirely during a direct DCO data modulation. The switching power amplifier integrates its matching network while operating in class-E/F2 to maximally enhance its efficiency at low voltage. The transmitter is realized in 28 nm digital CMOS and satisfies all metal density and other manufacturing rules. It consumes 3.6 mW/5.5 mW while delivering 0 dBm/3 dBm RF power in Bluetooth Low-Energy mode.
关键词： Bluetooth Low-Energy,low-voltage oscillator,class-E/F2 power amplifier,All-digital PLL,low-power switching current-source transmitter,Internet of Things (IoT)
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE Asian Solid-State Circuits Conference (A-SSCC) - Macau, Macao (2019.11.4-2019.11.6)] 2019 IEEE Asian Solid-State Circuits Conference (A-SSCC) - A 0.7mm <sup>2</sup> 8.54mW FocusNet Display LSI for Power Reduction on OLED Smart-phones
摘要： A discontinuous conduction mode (DCM) zero-voltage switching (ZVS) scheme for a class-D power amplifier (PA) for wireless power transfer is presented. The sizes of the ZVS inductor and capacitor are reduced by 7.5 and 5 times and ZVS is achieved even subject to PA supply voltage and output current variations. The class-D PA was fabricated with a 0.35 μm high-voltage CMOS process. The ZVS LC resonant tank consists of a 39 nH inductor and a 200 nF capacitor. The switching frequency was 6.78 MHz and the supply voltage was 20 V. Measurement results show that the PA delivered an output power of 7.18 W with a peak efficiency of 87.0%.
关键词： power amplifier,wireless power transfer,Class-D,zero-voltage switching (ZVS)
更新于2025-09-23 15:21:01
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[IEEE 2020 IEEE Radio and Wireless Symposium (RWS) - San Antonio, TX, USA (2020.1.26-2020.1.29)] 2020 IEEE Radio and Wireless Symposium (RWS) - Terahertz Channel Characterization using a Silicon-based Picosecond Pulse Source
摘要： In this paper, we exploit an idea of coupling multiple oscillators to reduce phase noise (PN) to beyond the limit of what has been practically achievable so far in a bulk CMOS technology. We then apply it to demonstrate for the first time an RF oscillator that meets the most stringent PN requirements of cellular basestation receivers while abiding by the process technology reliability rules. The oscillator is realized in digital 65-nm CMOS as a dual-core LC-tank oscillator based on a high-swing class-C topology. It is tunable within 4.07–4.91 GHz, while drawing 39–59 mA from a 2.15 V power supply. The measured PN is ?146.7 dBc/Hz and ?163.1 dBc/Hz at 3 MHz and 20 MHz offset, respectively, from a 4.07 GHz carrier, which makes it the lowest reported normalized PN of an integrated CMOS oscillator. Straightforward expressions for PN and interconnect resistance between the cores are derived and verified against circuit simulations and measurements. Analysis and simulations show that the interconnect resistance is not critical even with a 1% mismatch between the cores. This approach can be extended to a higher number of cores and achieve an arbitrary reduction in PN at the cost of the power and area.
关键词： LC-tank,figure of merit (FoM),phase noise,class-C oscillator,Basestation (BTS),coupled oscillators
更新于2025-09-23 15:21:01
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[IEEE 2019 Twelfth International Conference on Mobile Computing and Ubiquitous Network (ICMU) - Kathmandu, Nepal (2019.11.4-2019.11.6)] 2019 Twelfth International Conference on Mobile Computing and Ubiquitous Network (ICMU) - Human Tracking of Single Laser Range Finder Using Features Extracted by Deep Learning
摘要： Human recognition using single laser range finder (LRF) is utilized for the task of following a target person such as a cargo transport robot. In these recognition methods, the approach is applied in which human-crafted features is inputted to the one-class classification model to identify whether it is a human or not. In this paper, we propose a method that introduce features extracted by deep learning. In this method, we create an encoder that can extract features from input data using PointNet-based autoencoder. In its experiment, the features extracted by encoder is compared with the human-crafted features, and these extraction process length of time is measured.
关键词： One-Class Classification,Point Cloud,Deep Learning,Laser Range Finder
更新于2025-09-23 15:21:01
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[IEEE 2019 19th International Conference on Control, Automation and Systems (ICCAS) - Jeju, Korea (South) (2019.10.15-2019.10.18)] 2019 19th International Conference on Control, Automation and Systems (ICCAS) - A Portable Functional Near-Infrared Spectroscopy System Using 4-wavelength LEDs
摘要： Class EF and Class E/F inverters are hybrid inverters that combine the improved switch voltage and current waveforms of Class F and Class F-1 inverters with the ef?cient switching of Class E inverters. As a result, their ef?ciency, output power and power output capability can be higher in some cases than the Class E inverter. Little is known about these inverters and no attempt has been made to provide an in depth analysis on their performance. The design equations that have been previously derived are limited and are only applicable under certain assumptions. This paper is the ?rst to provide a comprehensive set of analytical analysis of Class EF and Class E/F inverters. The Class EF2 inverter is then studied in further detail and three special operation cases are de?ned that allow it to either operate at maximum power-output capability, maximum switching frequency, or maximum output power. Final design equations are provided to allow for rapid design and development. Experimental results are provided to con?rm the accuracy of the performed analysis based on a 23-W Class EF2 inverter at 6.78-MHz and 8.60-MHz switching frequencies. The results also show that the Class EF2 inverter achieved an ef?ciency of 91% compared to a 88% ef?ciency when operated as a Class E inverter.
关键词： high-frequency inverters,Class EF inverters,Class E inverters
更新于2025-09-23 15:19:57
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[IEEE 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Sozopol, Bulgaria (2019.9.6-2019.9.8)] 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Laser Stimulation of Retina and Optic Nerve in Children with Anisometropic Amblyopia
摘要： Extreme learning machine (ELM) is emerged as an effective, fast, and simple solution for real-valued classification problems. Various variants of ELM were recently proposed to enhance the performance of ELM. Circular complex-valued extreme learning machine (CC-ELM), a variant of ELM, exploits the capabilities of complex-valued neuron to achieve better performance. Another variant of ELM, weighted ELM (WELM) handles the class imbalance problem by minimizing a weighted least squares error along with regularization. In this paper, a regularized weighted CC-ELM (RWCC-ELM) is proposed, which incorporates the strength of both CC-ELM and WELM. Proposed RWCC-ELM is evaluated using imbalanced data sets taken from Keel repository. RWCC-ELM outperforms CC-ELM and WELM for most of the evaluated data sets.
关键词： extreme learning machine,Real valued classification,complex valued neural network,class imbalance problem,regularization,weighted least squares error
更新于2025-09-23 15:19:57
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Closed Loop Control of a Series Class-E Voltage-Clamped Resonant Converter for LED Supply with Dimming Capability
摘要： In this work, a new closed-loop control system is applied to a class-E resonant DC–DC converter with voltage clamp used for light-emitting diode (LED) supply. The proposed power topology was first described by Ribas et al. in a recent work. In the present paper, the LED current is sensed and used to implement a feedback control loop instead of the simplified feedforward scheme used in this previous reference. To design the control, a novel, simplified small-signal model is presented. This model is used to analyze the converter behavior as a function of the output power. The proposed approximation is significantly simpler than the multifrequency averaging technique normally used to analyze resonant converters. The feedback control loop is designed to reduce the LED low frequency current ripple while providing dimming control. Both the model and the control are verified by simulation and laboratory experimentation and the results obtained are in good accordance with the expected values.
关键词： small-signal dynamic model,light-emitting diode (LED) driver,high efficiency LEDs,resonant DC–DC converter,Class-E inverter,single-switch topology,closed-loop control,voltage clamp
更新于2025-09-23 15:19:57
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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) - New designed electrode patterns on rear side of bifacial PERC solar cells
摘要： Present-day smartphones and tablets demand high audio fidelity (e.g., total harmonic distortion + noise, THD + N < 0.01%), and high noise immunity (e.g., power supply rejection ratio, PSRR > 80 dB) to allow high integration in an SoC. The design of conventional closed-loop pulse width modulation (PWM) Class-D amplifiers (CDAs) typically involves undesirable trade-offs between fidelity (qualified by THD + N), PSRR and switching frequency. In this paper, we propose a fully integrated CMOS CDA that embodies a novel input-modulated carrier generator and a novel phase-error-free PWM modulator, collectively allowing the employment of high loop-gain to achieve high PSRR, yet without compromising linearity/dynamic-range or resorting to high switching frequency. The prototype CDA, realized in 65 nm CMOS, achieves a THD + N of 0.0027% and a power efficiency of 94% when delivering 500 mW to an 8 ? load from VDD = 3.6 V. The PSRR of the prototype CDA is very high, –101 dB @217 Hz and 90 dB @1 kHz, arguably the highest to-date. Furthermore, the switching frequency of the prototype CDA varies from 320 to 420 kHz, potentially reducing the EMI due to spread-spectrum. In addition, the prototype CDA is versatile with a large operating-voltage range, with VDD ranging from rechargeable 1.2 V single battery to standard 3.6 V smart-device supply voltages.
关键词： Audio power amplifiers,power supply rejection ratio (PSRR),total harmonic distortion (THD),pulse width modulation (PWM),class D amplifiers
更新于2025-09-23 15:19:57
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Phase-Compensated Optical Fiber-Based Ultrawideband Channel Sounder
摘要： Extreme learning machine (ELM) is emerged as an effective, fast, and simple solution for real-valued classification problems. Various variants of ELM were recently proposed to enhance the performance of ELM. Circular complex-valued extreme learning machine (CC-ELM), a variant of ELM, exploits the capabilities of complex-valued neuron to achieve better performance. Another variant of ELM, weighted ELM (WELM) handles the class imbalance problem by minimizing a weighted least squares error along with regularization. In this paper, a regularized weighted CC-ELM (RWCC-ELM) is proposed, which incorporates the strength of both CC-ELM and WELM. Proposed RWCC-ELM is evaluated using imbalanced data sets taken from Keel repository. RWCC-ELM outperforms CC-ELM and WELM for most of the evaluated data sets.
关键词： extreme learning machine,Real valued classification,complex valued neural network,class imbalance problem,regularization,weighted least squares error
更新于2025-09-23 15:19:57
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Multi-task image set classification via joint representation with class-level sparsity and intra-task low-rankness
摘要： Image set classification has recently attracted great attention due to its widespread applications in computer vision and pattern recognition. The great challenges lie in effectively and efficiently measuring the similarity among image sets with high inter-class ambiguity and large intra-class variability. In this paper, we propose a joint representation based approach to image set classification, in which class-level sparse and globally low rank constraints are imposed on the representation coefficients to embody inter-set discrimination and intra-set commonality respectively. Furthermore, sometimes the small size of image sets or improper usage of a single kind of features causes useful information limited and lacking in discriminability. To address this problem, we extend the traditional image set classification to a multi-task version, i.e., modify the proposed model to incorporate multiple kinds of features. Fortunately, on the total multi-task representation coefficients, both the total class-level sparsity and the intra-task low-rankness constraints still apply. The proposed method is optimized as a non-smooth convex optimization problem by employing an alternating optimization technique. Experiments on five public datasets demonstrate that the proposed method surpasses existing joint representation models with various regularizations for image set classification and compares favorably with other state-of-the-art methods.
关键词： Class-level sparsity,Multi-task recognition,Image set classification,Low-rankness
更新于2025-09-19 17:15:36