This paper presents a miniaturized wideband high-gain microstrip end-fire antenna specifically designed for 5G-R communication applications.The antenna structure comprises a microstrip folded dipole resonator and end-...This paper presents a miniaturized wideband high-gain microstrip end-fire antenna specifically designed for 5G-R communication applications.The antenna structure comprises a microstrip folded dipole resonator and end-fire directing units.By employing Intercalated Coupling Structures(ICS)between the folded dipole resonator and the ground plane,the resonant frequency of the antenna is shifted to lower frequencies,thereby significantly enhancing the operational bandwidth.Furthermore,the inclusion of three end-fire directing units positioned in front of the folded dipole oscillator substantially improves the antenna's end-fire gain.The designed antenna exhibits a relative impedance bandwidth of 46%(ranging from 1.36 to 2.18 GHz),with a peak gain of 7.33 dBi at the 2100 MHz 5G-R frequency band.The overall dimensions of the antenna are 0.31λ_(L)×0.39λ_(L)×0.008λ_(L),whereλ_(L)denotes the wavelength at the lowest frequency.The proposed antenna demonstrates a broad operational bandwidth,rendering it suitable for 5G-R mobile communications.展开更多
In this paper,by using the well-known high-gain observer design,an update law for the gain and an adaptive estimation of parameters,a new method of fault diagnosis for a class of nonlinear systems is presented.Without...In this paper,by using the well-known high-gain observer design,an update law for the gain and an adaptive estimation of parameters,a new method of fault diagnosis for a class of nonlinear systems is presented.Without resort to any transformation for the parameters,the estimation errors of the states and the parameters are guaranteed to be globally exponentially convergent by a persistent excitation condition.Compared to the existing results,it can be applied to nonlinear systems with nonlinear terms admitting an incremental rate depending on the measured output.A case study further verifies the validity of the proposed research.展开更多
In this paper a metamaterial-inspired antenna with high gain and good directivity is designed. Based on the concept of composite right/left-handed transmission line (CRLH-TL), the proposed antenna is realized based on...In this paper a metamaterial-inspired antenna with high gain and good directivity is designed. Based on the concept of composite right/left-handed transmission line (CRLH-TL), the proposed antenna is realized based on three leakage wave unit cell and a left handed circular ring slot incorporated on the surface. The maximum achievable gain at the resonant frequency of 5.6GHz is 6.933 dBi, and the return loss at 5.6 GHz can be –20 db. This proposed design has a simple structure and a compact dimension of 35 mm*40 mm*1 mm, which is suitable for particular wireless communication application such as WiFi and WLAN.展开更多
In this paper, a full-order observer which can be fully decoupled from the unknown inputs as the conventional full-order observer does is designed by using auxiliary outputs, but the requirement of the matching condit...In this paper, a full-order observer which can be fully decoupled from the unknown inputs as the conventional full-order observer does is designed by using auxiliary outputs, but the requirement of the matching condition is removed. The procedure of calculating the parameter matrices of the full-order observer is also presented. Compared with the existing auxiliary outputs based sliding-mode observers, the designed observer has a simpler design procedure, which is systematic and does not involve solving linear matrix inequalities. The simulation results show that the proposed method is effective.展开更多
It is well known that -nitride semiconductors can generate the magnitude of MV/cm polarization electric field which is comparable with their ionization electric fields. To take full advantage of the polarization elect...It is well known that -nitride semiconductors can generate the magnitude of MV/cm polarization electric field which is comparable with their ionization electric fields. To take full advantage of the polarization electric field, we design an N-face AlGaN solar-blind avalanche photodiode (APD) with an Al<sub>0.45</sub>Ga<sub>0.55</sub>N/Al<sub>0.3</sub>Ga<sub>0.7</sub>N heterostructure as separate absorption and multiplication (SAM) regions. The simulation results show that the N-face APDs are more beneficial to improving the avalanche gain and reducing the avalanche breakdown voltage compared with the Ga-face APDs due to the effect of the polarization electric field. Furthermore, the Al<sub>0.45</sub>Ga<sub>0.55</sub>N/Al<sub>0.3</sub>Ga<sub>0.7</sub>N heterostructure SAM regions used in APDs instead of homogeneous Al<sub>0.45</sub>Ga<sub>0.55</sub>N SAM structure can increase significantly avalanche gain because of the increased hole ionization coefficient by using the relatively low Al-content AlGaN in the multiplication region. Meanwhile, a quarter-wave AlGaN/AlN distributed Bragg reflector structure at the bottom of the device is designed to remain a solar-blind characteristic of the heterostructure SAM-APDs.展开更多
A novel three layers microstrip antenna element that has the advantages of wideband and high-gain is proposed. The eigenvalue equation and the frequency characteristic formulas of the input Voltage Stand Wave Ratio ( ...A novel three layers microstrip antenna element that has the advantages of wideband and high-gain is proposed. The eigenvalue equation and the frequency characteristic formulas of the input Voltage Stand Wave Ratio ( VSWR ) are obtained by using the spectral domain method and equivalent circuit method, respectively. With the aid of the numerical results, a C-band microstrip antenna element with bandwidth of 16% (VSWR【1.5) or 25% (VSWR【2) and gain of 10.2-11.3 dB is developed, which are much larger than the bandwidth of 5-6% and the gain of 6-7 dB of the common microstrip antenna element.展开更多
Energy-harvesting technologies enable the extraction of energy from environmental sources characterized by extremely low voltages.A high-gain DC-DC converter with an ultralow input voltage is necessary for voltage con...Energy-harvesting technologies enable the extraction of energy from environmental sources characterized by extremely low voltages.A high-gain DC-DC converter with an ultralow input voltage is necessary for voltage conversion to supply energy to sensors,batteries,and other devices.However,existing ultra-low-voltage boost converters typically exhibit limited output power,posing significant challenges in fully utilizing the available energy,particularly in applications such as high-voltage direct-current(HVDC)transmission line voltage-difference energy harvesting.To maximize the harvested energy,this study proposes a high-gain DC-DC converter designed for operation withultra-low input voltage.The proposed converter utilizes a hybrid inductor-switch-capacitor(LSC)boost network,which offersadvantages such as high voltage gain,increased output power,and straightforwardcontrol mechanisms.Experimental findings indicatethat theconverter achieves output power ranging from 10 to 210 mW with input voltages between 100 and 300 mV,delivering an output voltage of 5 V.This performance surpasses that of existing ultra-low-voltage boosting methods,providing a more effective solution for energy-harvesting applications.展开更多
The integration of high-gain DC-DC converters into photovoltaic(PV)systems plays a crucial role in enhancing energy conversion efficiency and ensuring stable grid interfacing.Photovoltaic panels inherently produce low...The integration of high-gain DC-DC converters into photovoltaic(PV)systems plays a crucial role in enhancing energy conversion efficiency and ensuring stable grid interfacing.Photovoltaic panels inherently produce low-voltage DC output,which requires significant voltage boosting to meet the requirements of grid-tied inverters or energy storage systems.This paper presents a comprehensive review of high-gain DC-DC converter topologies,design principles,and their applications in photovoltaic power generation.Key design challenges such as voltage stress,efficiency optimization,electromagnetic interference(EMI),and thermal management are discussed in detail.Advanced control strategies,including pulse-width modulation(PWM),maximum power point tracking(MPPT),and dynamic stability analysis,are analyzed to ensure reliable and efficient operation under varying environmental conditions.The paper also highlights the advantages of soft-switching techniques and multistage converter architectures in achieving high voltage gains with reduced losses.Overall,the integration of optimized high-gain converters significantly improves photovoltaic system performance,promoting wider adoption of solar energy technologies.展开更多
This paper proposes a novel cascaded high-gain state and perturbation observer(CHGSPO)-based feedback linearization control(FLC)strategy for mitigating the sub-synchronous resonance(SSR)caused by the interactions betw...This paper proposes a novel cascaded high-gain state and perturbation observer(CHGSPO)-based feedback linearization control(FLC)strategy for mitigating the sub-synchronous resonance(SSR)caused by the interactions between the series capacitor and doubly-fed induction generator-based wind farms(DFIGWFs).The CHGSPO is designed to estimate both the state and nonlinear perturbations of the series-compensated DFIGWF system.The nonlinear perturbation contains the disturbance originated from SSR,nonlinearities and uncertainties of the system model.The estimated state and perturbations are used by the FLC to eliminate the nonlinearities of the system and realize complete decoupling control of the DFIGWF.Additionally,the FLC effectively suppresses oscillatory signals detected by the CHGSPO.The proposed CHGSPO-based FLC exhibits remarkable robustness against uncertainties and external disturbances.The results of modal analysis and time domain simulations demonstrate the effectiveness of the proposed control strategy in SSR mitigation of the series-compensated DFIGWF system.展开更多
为了进一步解决基于电容-二极管(capacitance-diode,CD)升压单元的两相交错并联Boost高增益变换器存在的开关管数量多、输入输出不共地问题,提出了一种基于CD单元的新型3L型两相交错并联Boost变换器拓扑的构建方法,并根据在第3个升压电...为了进一步解决基于电容-二极管(capacitance-diode,CD)升压单元的两相交错并联Boost高增益变换器存在的开关管数量多、输入输出不共地问题,提出了一种基于CD单元的新型3L型两相交错并联Boost变换器拓扑的构建方法,并根据在第3个升压电感前级和后级引入CD单元数量的不同,推演出基于FN-BMCD单元的3L型高增益Boost变换器的演化规律;以F2-B1CD单元的3L型Boost变换器为例,详细分析了5个开关模态的工作原理,揭示了各电感及电容寄生参数对电压增益的影响机理;搭建由数字信号处理(digital signal processing,DSP)芯片和实时仿真机组成的控制在环半实物仿真实验平台,验证了所提新型变换器拓扑理论分析的正确性。展开更多
This paper addresses the synchronization of follower agents’state vectors with that of a leader in high-order nonlinear multi-agent systems.The proposed low-complexity control scheme employs high-gain observers to es...This paper addresses the synchronization of follower agents’state vectors with that of a leader in high-order nonlinear multi-agent systems.The proposed low-complexity control scheme employs high-gain observers to estimate higher-order synchronization errors,enabling the controller to rely solely on relative output measurements.This approach significantly reduces the dependence on full-state information,which is often infeasible or costly in practical engineering applications.An output feedback control strategy is developed to overcome these limitations while ensuring robust and effective synchronization.Simulation results are provided to demonstrate the effectiveness of the proposed approach and validate the theoretical findings.展开更多
We report our experimental observation of charge domain oscillation in semi-insulating GaAs photocon-ductive semiconductor switches (PCSSs). The high-gain PCSS is intrinsically a photon-activated charge domain device....We report our experimental observation of charge domain oscillation in semi-insulating GaAs photocon-ductive semiconductor switches (PCSSs). The high-gain PCSS is intrinsically a photon-activated charge domain device. It is the photon-activated carriers that satisfy the requirement of charge domain formation on carrier concentration and device length product of 1012 cm-2. We also show that, because of the repeated process of domain formation, the domain travels with a compromised speed of electron saturation velocity and the speed of light. As a result, the transit time of charge domains in PCSS is much shorter than that of traditional Gunn domains.展开更多
基金supported in part by the National Natural Science Foundation of China(Nos.U2268201,62271419)in part by the State Key Laboratory of Rail Transit Engineering Informatization(FSDI)under Grant 2022KY50ZD(ZNXT)-01.
文摘This paper presents a miniaturized wideband high-gain microstrip end-fire antenna specifically designed for 5G-R communication applications.The antenna structure comprises a microstrip folded dipole resonator and end-fire directing units.By employing Intercalated Coupling Structures(ICS)between the folded dipole resonator and the ground plane,the resonant frequency of the antenna is shifted to lower frequencies,thereby significantly enhancing the operational bandwidth.Furthermore,the inclusion of three end-fire directing units positioned in front of the folded dipole oscillator substantially improves the antenna's end-fire gain.The designed antenna exhibits a relative impedance bandwidth of 46%(ranging from 1.36 to 2.18 GHz),with a peak gain of 7.33 dBi at the 2100 MHz 5G-R frequency band.The overall dimensions of the antenna are 0.31λ_(L)×0.39λ_(L)×0.008λ_(L),whereλ_(L)denotes the wavelength at the lowest frequency.The proposed antenna demonstrates a broad operational bandwidth,rendering it suitable for 5G-R mobile communications.
基金supported by the National Science Foundation of China(No.61074091)the National Science Foundation of Hubei Province(No.2008CDZ046,2008CDZ047)+1 种基金the Scientific Innovation Team Project of Hubei Provincial Department of Education(No.T200809)the Science Foundation of Education Commission of Hubei Province(No.D20091305)
文摘In this paper,by using the well-known high-gain observer design,an update law for the gain and an adaptive estimation of parameters,a new method of fault diagnosis for a class of nonlinear systems is presented.Without resort to any transformation for the parameters,the estimation errors of the states and the parameters are guaranteed to be globally exponentially convergent by a persistent excitation condition.Compared to the existing results,it can be applied to nonlinear systems with nonlinear terms admitting an incremental rate depending on the measured output.A case study further verifies the validity of the proposed research.
文摘In this paper a metamaterial-inspired antenna with high gain and good directivity is designed. Based on the concept of composite right/left-handed transmission line (CRLH-TL), the proposed antenna is realized based on three leakage wave unit cell and a left handed circular ring slot incorporated on the surface. The maximum achievable gain at the resonant frequency of 5.6GHz is 6.933 dBi, and the return loss at 5.6 GHz can be –20 db. This proposed design has a simple structure and a compact dimension of 35 mm*40 mm*1 mm, which is suitable for particular wireless communication application such as WiFi and WLAN.
基金Supported by the National Natural Science Foundation of China(No.61203299)
文摘In this paper, a full-order observer which can be fully decoupled from the unknown inputs as the conventional full-order observer does is designed by using auxiliary outputs, but the requirement of the matching condition is removed. The procedure of calculating the parameter matrices of the full-order observer is also presented. Compared with the existing auxiliary outputs based sliding-mode observers, the designed observer has a simpler design procedure, which is systematic and does not involve solving linear matrix inequalities. The simulation results show that the proposed method is effective.
基金Supported by the State Key Project of Research and Development Plan of China under Grant No 2016YFB0400903the National Natural Science Foundation of China under Grant Nos 61634002,61274075 and 61474060+2 种基金the Key Project of Jiangsu Province under Grant No BE2016174the Anhui University Natural Science Research Project under Grant No KJ2015A153the Open Fund of State KeyLab of Optical Technologies on Nano-fabrication and Micro-engineering
文摘It is well known that -nitride semiconductors can generate the magnitude of MV/cm polarization electric field which is comparable with their ionization electric fields. To take full advantage of the polarization electric field, we design an N-face AlGaN solar-blind avalanche photodiode (APD) with an Al<sub>0.45</sub>Ga<sub>0.55</sub>N/Al<sub>0.3</sub>Ga<sub>0.7</sub>N heterostructure as separate absorption and multiplication (SAM) regions. The simulation results show that the N-face APDs are more beneficial to improving the avalanche gain and reducing the avalanche breakdown voltage compared with the Ga-face APDs due to the effect of the polarization electric field. Furthermore, the Al<sub>0.45</sub>Ga<sub>0.55</sub>N/Al<sub>0.3</sub>Ga<sub>0.7</sub>N heterostructure SAM regions used in APDs instead of homogeneous Al<sub>0.45</sub>Ga<sub>0.55</sub>N SAM structure can increase significantly avalanche gain because of the increased hole ionization coefficient by using the relatively low Al-content AlGaN in the multiplication region. Meanwhile, a quarter-wave AlGaN/AlN distributed Bragg reflector structure at the bottom of the device is designed to remain a solar-blind characteristic of the heterostructure SAM-APDs.
文摘A novel three layers microstrip antenna element that has the advantages of wideband and high-gain is proposed. The eigenvalue equation and the frequency characteristic formulas of the input Voltage Stand Wave Ratio ( VSWR ) are obtained by using the spectral domain method and equivalent circuit method, respectively. With the aid of the numerical results, a C-band microstrip antenna element with bandwidth of 16% (VSWR【1.5) or 25% (VSWR【2) and gain of 10.2-11.3 dB is developed, which are much larger than the bandwidth of 5-6% and the gain of 6-7 dB of the common microstrip antenna element.
基金Supported by Guangdong Basic and Applied Basic Research Foundation,China(2022A1515240036).
文摘Energy-harvesting technologies enable the extraction of energy from environmental sources characterized by extremely low voltages.A high-gain DC-DC converter with an ultralow input voltage is necessary for voltage conversion to supply energy to sensors,batteries,and other devices.However,existing ultra-low-voltage boost converters typically exhibit limited output power,posing significant challenges in fully utilizing the available energy,particularly in applications such as high-voltage direct-current(HVDC)transmission line voltage-difference energy harvesting.To maximize the harvested energy,this study proposes a high-gain DC-DC converter designed for operation withultra-low input voltage.The proposed converter utilizes a hybrid inductor-switch-capacitor(LSC)boost network,which offersadvantages such as high voltage gain,increased output power,and straightforwardcontrol mechanisms.Experimental findings indicatethat theconverter achieves output power ranging from 10 to 210 mW with input voltages between 100 and 300 mV,delivering an output voltage of 5 V.This performance surpasses that of existing ultra-low-voltage boosting methods,providing a more effective solution for energy-harvesting applications.
文摘The integration of high-gain DC-DC converters into photovoltaic(PV)systems plays a crucial role in enhancing energy conversion efficiency and ensuring stable grid interfacing.Photovoltaic panels inherently produce low-voltage DC output,which requires significant voltage boosting to meet the requirements of grid-tied inverters or energy storage systems.This paper presents a comprehensive review of high-gain DC-DC converter topologies,design principles,and their applications in photovoltaic power generation.Key design challenges such as voltage stress,efficiency optimization,electromagnetic interference(EMI),and thermal management are discussed in detail.Advanced control strategies,including pulse-width modulation(PWM),maximum power point tracking(MPPT),and dynamic stability analysis,are analyzed to ensure reliable and efficient operation under varying environmental conditions.The paper also highlights the advantages of soft-switching techniques and multistage converter architectures in achieving high voltage gains with reduced losses.Overall,the integration of optimized high-gain converters significantly improves photovoltaic system performance,promoting wider adoption of solar energy technologies.
文摘This paper proposes a novel cascaded high-gain state and perturbation observer(CHGSPO)-based feedback linearization control(FLC)strategy for mitigating the sub-synchronous resonance(SSR)caused by the interactions between the series capacitor and doubly-fed induction generator-based wind farms(DFIGWFs).The CHGSPO is designed to estimate both the state and nonlinear perturbations of the series-compensated DFIGWF system.The nonlinear perturbation contains the disturbance originated from SSR,nonlinearities and uncertainties of the system model.The estimated state and perturbations are used by the FLC to eliminate the nonlinearities of the system and realize complete decoupling control of the DFIGWF.Additionally,the FLC effectively suppresses oscillatory signals detected by the CHGSPO.The proposed CHGSPO-based FLC exhibits remarkable robustness against uncertainties and external disturbances.The results of modal analysis and time domain simulations demonstrate the effectiveness of the proposed control strategy in SSR mitigation of the series-compensated DFIGWF system.
文摘为了进一步解决基于电容-二极管(capacitance-diode,CD)升压单元的两相交错并联Boost高增益变换器存在的开关管数量多、输入输出不共地问题,提出了一种基于CD单元的新型3L型两相交错并联Boost变换器拓扑的构建方法,并根据在第3个升压电感前级和后级引入CD单元数量的不同,推演出基于FN-BMCD单元的3L型高增益Boost变换器的演化规律;以F2-B1CD单元的3L型Boost变换器为例,详细分析了5个开关模态的工作原理,揭示了各电感及电容寄生参数对电压增益的影响机理;搭建由数字信号处理(digital signal processing,DSP)芯片和实时仿真机组成的控制在环半实物仿真实验平台,验证了所提新型变换器拓扑理论分析的正确性。
文摘四开关Buck-Boost(Four-switch Buck-Boost,FSBB)变换器因其电压应力低,无源器件少等特性在光伏(photovoltaic,PV)发电系统中受到了广泛关注。针对其在参数变化及输入电压大范围变化时动态性能衰减的问题,本文提出了一种结合扩张高增益状态观测器(extended high-gain state observer,EHGSO)的模型预测控制方法。首先建立了4模式控制下FSBB的状态空间模型并推导出了FSBB预测电流控制方法;然后设计了EHGSO对控制误差进行了有效补偿,实现了在参数变化和输入电压大范围变化等复杂因素影响下的快速稳定控制;最后通过实验验证了所提控制方法的有效性。
文摘This paper addresses the synchronization of follower agents’state vectors with that of a leader in high-order nonlinear multi-agent systems.The proposed low-complexity control scheme employs high-gain observers to estimate higher-order synchronization errors,enabling the controller to rely solely on relative output measurements.This approach significantly reduces the dependence on full-state information,which is often infeasible or costly in practical engineering applications.An output feedback control strategy is developed to overcome these limitations while ensuring robust and effective synchronization.Simulation results are provided to demonstrate the effectiveness of the proposed approach and validate the theoretical findings.
基金This work was supported by the National Natural Sci-ence Foundation of China under Grant No.50077017.
文摘We report our experimental observation of charge domain oscillation in semi-insulating GaAs photocon-ductive semiconductor switches (PCSSs). The high-gain PCSS is intrinsically a photon-activated charge domain device. It is the photon-activated carriers that satisfy the requirement of charge domain formation on carrier concentration and device length product of 1012 cm-2. We also show that, because of the repeated process of domain formation, the domain travels with a compromised speed of electron saturation velocity and the speed of light. As a result, the transit time of charge domains in PCSS is much shorter than that of traditional Gunn domains.
