检索结果-南通市图书馆

Mechanism of the self-changing parameters and characteristics in AlGaN/GaN high-electron mobility transistors after a step voltage stress

在线全文

学校读者我要写书评

暂无评论

Journal of Semiconductors 2015年第7期36卷 78-82页

作者：石磊冯士维刘琨张亚民 college of Electronic information and control engineering Beijing University of Technology

The phenomenon of self-changing on the device parameters and characteristics after a step voltage stress was applied to the gate is studied in A1GaN/GaN high electron mobility transistors. The device was measured every 5 rain after the stress was removed. The large-signal parasitic source （drain） resistance, transfer characteristics, threshold voltage, drain-source current, gate-source （drain） reverse currenwvoltage characteristics changed spontaneously after the removal of the stress. The time constant of tile self-changing was about 25 27 rain. The gate-source （drain） capacitance-voltage characteristics were constant during this process. Electrons were trapped by the surface states and traps in the AIGaN barrier layer when the device was under stress. The traps in the AIGaN barrier layer then released electrons in less than 10 s. The surface states released electrons continuously during the entire measurement stage, leading to the self-changing of mearsurement result.

关键词： AIGaN/GaN HEMTs surface states self-changing stress

0.9 GHz and 2.4 GHz dual-band SiGe HBT LNA

在线全文

学校读者我要写书评

暂无评论

Journal of Semiconductors 2013年第2期34卷 67-71页

作者：路志义谢红云霍文娟张万荣 college of Electronic information and control engineering Beijing University of Technology

This paper presents design and implementation of a dual-band LNA using a 0.35 #m SiGe HBT process for 0.9 GHz GSM and 2.4 GHz WLAN applications. PCB layout parasitic effects have a vital effect on circuit performance and are accounted for using electro-magnetic （EM） simulation. Design considerations of noise decoupling, input/output impedance matching, and current reuse are described in detail. At 0.9/2.4 GHz, gain and noise figure are 13/16 dB and 4.2/3.9 dB, respectively. Both S11 and S22 are below -10 dB. Power dissipation is 40 mW at 3.5 V supply.

关键词： current reuse dual-band emitter inductor EM simulation SiGe HBT

Restabilizing Mechanisms after the Onset of Thermal Instability in Bipolar Transistors

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2011年第7期28卷 313-315页

作者： CHEN Liang ZHANG Wan-Rong XIE Hong-Yun JIN Dong-Yue DING Chun-Bao FU Qiang WANG Ren-Qing XIAO Ying ZHAO Xin college of Electronic information and control engineering Beijing University of TechnologyBeijing 100124

The restabilizing mechanisms after the onset of thermal instability in bipolar transistors are studied by theoretical analyses,computer simulations and experimental *** conditions are described by novel analytical ***,the expression of collect current in the second fly-back point is given for the first *** effects of emitter ballast resistance,collector-emitter voltage and thermal resistance on restabilization mechanisms are expressed and investigated.

关键词： emitter bipolar resistance

Discrete-Time Mean-Field Stochastic H_2/H_∞ control

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2017年第4期30卷 765-781页

作者： ZHANG Weihai MA Limin ZHANG Tianliang college of Electrical engineering and Automation Shandong University of Science and Technology Science and information college Qingdao Agricultural University college of information and control engineering China University of Petroleum (East China)

The finite horizon H_2/H_∞ control problem of mean-field type for discrete-time systems is considered in this paper. Firstly, the authors derive a mean-field stochastic bounded real lemma(SBRL). Secondly, a sufficient condition for the solvability of discrete-time mean-field stochastic linearquadratic(LQ) optimal control is presented. Thirdly, based on SBRL and LQ results, this paper establishes a sufficient condition for the existence of discrete-time stochastic H_2/H_∞ control of meanfield type via the solvability of coupled matrix-valued equations.

关键词： Discrete-time systems H2/H∞ control mean-field.

Optimal spectrum allocation of primary users in light-handed cognitive radio networks

在线全文

学校读者我要写书评

暂无评论

Journal of Harbin Institute of Technology(New Series) 2012年第3期19卷 21-27页

作者：司鹏博孙恩昌张延华 college of Electronic information and control engineering Beijing University of Technology college of Electronic information and control engineering Beijing University of Technology100124 BeijingChina

In traditional cognitive radio(CR) network,secondary users(SUs) are always assumed to obey the rule of"introducing no interference to the primary users(PUs) ".However,this assumption may be not realistic as the CR devices becoming more and more intelligent *** this paper,with the concept of lighthanded CR,which is proposed to deal with the above mentioned problem by enforcing"punishment"to illegal CR transmissions,the action decisions of primary users(PUs) are modeled as a partially observable Markov decision process(POMDP),and the optimal spectrum allocation scheme with the objective of maximizing their reward is proposed,which is defined by the utility ***,a reduced scheme with much smaller state space has been proposed in this paper for lower computational *** simulation results show that the proposed schemes improve the reward significantly compared to the existing scheme.

关键词： cognitive radio networks light-handed CR optimal decision making POMDP

Adaptive control of a Flexible Manipulator With Unknown Hysteresis and Intermittent Actuator Faults

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2025年第1期 148-158页

作者： Shouyan Chen Weitian He Zhijia Zhao Yun Feng Zhijie Liu Keum-Shik Hong School of Mechanical and Electrical engineering Guangzhou University the School of control Science and engineering Shandong University IEEE the college of Electrical and information engineering Hunan University the National engineering Research Center for Robot Visual Perception and control Technology Hunan University the School of Intelligence Science and Technology University of Science and Technology Beijing (USTB) the Institute for Future the School of AutomationQingdao University the School of Mechanical engineering Pusan National University

In this study, we consider a single-link flexible manipulator in the presence of an unknown Bouc-Wen type of hysteresis and intermittent actuator faults. First, an inverse hysteresis dynamics model is introduced, and then the control input is divided into an expected input and an error compensator. Second,a novel adaptive neural network-based control scheme is proposed to cancel the unknown input hysteresis. Subsequently,by modifying the adaptive laws and local control laws, a fault-tolerant control strategy is applied to address uncertain intermittent actuator faults in a flexible manipulator system. Through the direct Lyapunov theory, the proposed scheme allows the state errors to asymptotically converge to a specified interval. Finally,the effectiveness of the proposed scheme is verified through numerical simulations and experiments.

关键词：

Non-fragile switching tracking control for a flexible air-breathing hypersonic vehicle based on polytopic LPV model

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2013年第4期26卷 948-959页

作者： Huang Yiqing Sun Changyin Qian Chengshan Wang Li college of Electrical engineering Anhui Polytechnic University School of Automation Southeast University college of information and control Nanjing University of Information Science and Technology

This article proposes a linear parameter varying （LPV） switching tracking control scheme for a flexible air-breathing hypersonic vehicle （FAHV）. First, a polytopic LPV model is constructed to represent the complex nonlinear longitudinal model of the FAHV by using Jacobian linearization and tensor-product （T-P） model transformation approach. Second, for less conservative controller design purpose, the flight envelope is divided into four sub-regions and a non-fragile LPV controller is designed for each parameter sub-region. These non-fragile LPV controllers are then switched in order to guarantee the closed-loop FAHV system to be asymptotically stable and satisfy a specified performance criterion. The desired non-fragile LPV switching controller is found by solving a convex constraint problem which can be efficiently solved using available linear matrix inequality （LMI） techniques, and robust stability analysis of the closed-loop FAHV system is verified based on multiple Lypapunov functions （MLFs）. Finally, numerical simulations have demonstrated the effectiveness of the proposed approach.

关键词： Hypersonic vehicles Linear parameter varying Non-fragile control Switching control Tracking control

High-precision tip positioning composite feedforward control of linear colocated motion systems with Bi-Loop iterative feedforward tuning

在线全文

学校读者我要写书评

暂无评论

Science China Technological Sciences 2025年

作者： Junyu HU Yourui TAO Shanhu LI Xu HAN college of Mechanical and Vehicle engineering Hunan University State Key Laboratory of Reliability and Intelligence of Electrical Equipment Hebei University of Technology

To enhance the tip positioning accuracy and robustness against disturbances of linear colocated motion systems, a novel composite feedforward (COMFF) control with Bi-Loop iterative feedforward tuning (IFFT) is proposed. The tip positioning error consists of the coupled tip residual vibration and linear motor tracking error. Given the influence of nonlinear friction and load flexibility, the topology of COMFF is designed as decoupled structures so that COMFF can suppress the tip residual vibration and compensate for the linear motor tracking error compatibly. Furthermore, Bi-Loop IFFT is built to improve the robustness of COMFF in high-precision motor tracking performance. In the state space of the linear motor tracking error based on the projection theorem, two loops are performed in parallel along the iteration direction. One is the P-type iteration loop that drives linear motor tracking errors to converge to the zero state. The other is the observation loop constructed by the recursive least square with forgetting factors to accelerate the P-type iteration loop. Driven by the P-type iteration loop with the aid of the observation loop, the proposed COMFF is integrated with fast convergence and high robustness when confronted with model disturbances. The effectiveness of the proposed COMFF combined with Bi-Loop IFFT is validated by experiments.

关键词：

Full Diversity Reception Based on Dempster-Shafer Theory for Network Coding with Multiple-Antennas Relay

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

China Communications 2015年第10期12卷 76-90页

作者： SUN Yanhua YANG Yi LI Yonghua ZHANG Yanhua college of Electronic information and control engineering Beijing University of Technology School of information engineering Beijing University of Posts and Telecommunications

In this paper,a two-way relay system which achieves bi-directional communication via a multiple-antenna relay in two time slots is *** the multiple access(MA) phase,the novel receive schemes based on Dempster-Shafer(D-S) evidence theory are proposed at the relay *** of traditional linear detection,the first proposed MIMO-DS NC scheme adopts D-S evidence theory to detect the signals of each source node before mapping them into network-coded ***,different from traditional physical-layer network coding(PNC) based on virtual MIMO model,the further proposed MIMO-DS PNC comes from the vector space perspective and combines PNC mapping with D-S theory to obtain network-coded signal without estimating each source node signal.D-S theory can appropriately characterize uncertainty and make full use of multiple evidence source information by Dempster's combination rule to obtain reliable *** the broadcast(BC) phase,the space-time coding(STC) and antenna selection(AS) schemes are adopted to achieve transmit *** results reveal that the STC and AS schemes both achieve full transmit diversity in the BC phase and the proposed MIMO-DS NC/PNC schemes obtain better end-to-end BER performance and throughputs compared with traditional schemes with a little complexity increasing and no matter which scheme is adopted in the BC phase,MIMO-DS PNC always achieves full end-to-end diversity gain as MIMO-ML NC but with a lower complexity and its throughput approaches the throughput of MIMO-ML NC in high SNR regime.

关键词： network coding MIMO-DS NC/PNC Dempster-Shafer evidence theory twoway multiple antennas relay system