In this paper,a novel pulse density modulation(PDM)with semi-bridgeless active rectifier(S-BAR)in inductive power transfer(IPT)system for rail vehicle is proposed.It is to reduce switching losses of the active rectifi...In this paper,a novel pulse density modulation(PDM)with semi-bridgeless active rectifier(S-BAR)in inductive power transfer(IPT)system for rail vehicle is proposed.It is to reduce switching losses of the active rectifier in pickups.In the control method,the insulated-gate bipolar transistors(IGBTs)in the S-BAR are controlled by synchronous PDM signals,so that zero-voltage switching(ZVS)and zero-current switching(ZCS)can be achieved in the whole output power range.The output power is regulated by changing the pulse density(PD)of the S-BAR since the it is almost linear proportional with the PD in high quality factor of pickup side.The communication device between the primary side and pickup side is not necessary anymore.The detailed theoretical analyses of the PDM method are provided,and its advantages are shown in a 7.5kW IPT prototype for rail vehicle.The experimental results are presented to verify the analysis and demonstrate the performance.The overall efficiency of the system by PDM control is 74.2%which is improved by 4%compared with phase shift(PS)control at light load.展开更多
This paper presents a compact multi-band rectifier with an improved impedance matching bandwidth.It uses a combination of–matching network(MN)at Port-1,with a parallel connection of three cell branch MN at Port-2.The...This paper presents a compact multi-band rectifier with an improved impedance matching bandwidth.It uses a combination of–matching network(MN)at Port-1,with a parallel connection of three cell branch MN at Port-2.The proposed impedance matching network(IMN)is adopted to reduce circuit complexity,to improve circuit performance,and power conversion efficiency(PCE)of the rectifier at low input power.The fabricated rectifier prototype operates at 0.92,1.82,2.1,2.46 and 2.65 GHz covering GSM/900,GSM/1800,UMTS2100,and Wi-Fi/2.45–LTE2600.The size of the compact rectifier on the PCB board is 0.13λ_(g)×0.1λ_(g).The fabricated rectifier achieved an RF-to DC(radio frequency direct current)PCE of 31.8%,24%,22.7%,and 15%,and 14.1%for−20 dBm at the five respective measured operating frequencies.The circuit attains a peak RF-to-DC PCE of 82.3%for an input power of 3 dBm at 0.92 GHz.The proposed rectifier realizes an ambient output dc voltage of 454 mV for multi-tone input signals from the two ports.The rectifier drives a bq25504-674 power management module(PMM)to achieve 1.21 V from the two-port connection.The rectifier has the ability to exploit both frequency domain through the multi-band operation with good impedance bandwidth and a spatial domain using dual-port configuration.Hence,it is a potential candidate for various applications in radio frequency energy harvesting(RFEH)system.展开更多
A rectifier circuit for wireless energy harvesting(WEH) with a wide input power range is proposed in this paper. We build up accurate models of the diodes to improve the accuracy of the design of the rectifier. Due to...A rectifier circuit for wireless energy harvesting(WEH) with a wide input power range is proposed in this paper. We build up accurate models of the diodes to improve the accuracy of the design of the rectifier. Due to the nonlinear characteristics of the diodes, a new band-stop structure is introduced to reduce the imaginary part impedance and suppress harmonics. A novel structure with double branches and an optimized λ/4 microstrip line is proposed to realize the power division ratio adjustment by the input power automatically. The proposed two branches can satisfy the two cases with input power of-20 dBm to 0 dBm and 0 dBm to 15 dBm, respectively. Here, dBm = 10 log(P mW), and P represents power. An impedance compression network(ICN) is correspondingly designed to maintain the input impedance stability over the wide input power range. A rectifier that works at 2.45 GHz is implemented. The measured results show that the highest efficiency can reach 51.5% at the output power of 0 dBm and higher than 40% at the input power of-5 dBm to 12 dBm.展开更多
For the high resolution required in a digital interface circuit of an accelerometer used in feeble gravity measurement, a switched-capacitor (SC) sigma-delta modulator (SDM) is proposed. Based on the principle and...For the high resolution required in a digital interface circuit of an accelerometer used in feeble gravity measurement, a switched-capacitor (SC) sigma-delta modulator (SDM) is proposed. Based on the principle and the topology structure of the SDMs, the influence of oversampling ratio, bits of an internal quantizer and the cascaded structure on weak signal detecting precision is analyzed, and an ideal low-distortion SDM with a second-order 1-bit structure satisfying the high- resolution interface circuit of an accelerometer is designed. With the research on non-idealities of each SDM block in the SC circuit implementation and their impacts on power consumption, the realized parameters of low-power SDMs based on different bandwidths are devised and the power consumption of each SDM is estimated. Time-domain behavioral simulation is explored based on Simulink. The results demonstrate that a 21- bit resolution of the designed SDMs can be achieved on the premise of low power, and the parameters for the circuit implementation can be directed to the transistor-level circuit design.展开更多
The Generalized Falk Method(GFM)for coordinate transformation,together with two model-reduction strategies based on this method,are presented for efficient coupled field-circuit simulations.Each model-reduction strate...The Generalized Falk Method(GFM)for coordinate transformation,together with two model-reduction strategies based on this method,are presented for efficient coupled field-circuit simulations.Each model-reduction strategy is based on a decision to retain specific linearly-independent vectors,called trial vectors,to construct a vector basis for coordinate transformation.The reduced-order models are guaranteed to be stable and passive since the GFM is a congruence transformation of originally symmetric positive definite systems.We also show that,unlike the Pade-via-Lanczos(PVL)method,the GFM does not generate unstable positive poles while reducing the order´of circuit problems.Further,the proposed GFM is also faster when compared to methods of the type Lanczos(or Krylov)that are already widely used in circuit simulations for electrothermal and electromagnetic problems.The concept of response participation factors is introduced for the selection of the trial vectors in the proposed model-reduction methods.Further,we present methods to develop simple equivalent circuit networks for the field component of the overall field-circuit system.The implementation of these equivalent circuit networks in circuit simulators is discussed.With the proposed model-reduction strategies,significant improvement on the efficiency of the generalized Falk method is illustrated for coupled field-circuit problems.展开更多
Far-field wireless power transfer(WPT)is a major breakthrough technology that will enable the many anticipated ubiquitous Internet of Things(IoT)applications associated with fifth generation(5G),sixth generation(6G),a...Far-field wireless power transfer(WPT)is a major breakthrough technology that will enable the many anticipated ubiquitous Internet of Things(IoT)applications associated with fifth generation(5G),sixth generation(6G),and beyond wireless ecosystems.Rectennas,which are the combination of rectifying circuits and antennas,are the most critical components in far-field WPT systems.However,compact application devices require even smaller integrated rectennas that simultaneously have large electromagnetic wave capture capabilities,high alternating current(AC)-to-direct current(DC)(AC-to-DC)conversion efficiencies,and facilitate a multifunctional wireless performance.This paper reviews various rectenna miniaturization techniques such as meandered planar inverted-F antenna(PIFA)rectennas;miniaturized monopole-and dipole-based rectennas;fractal loop and patch rectennas;dielectric-loaded rectennas;and electrically small near-field resonant parasitic rectennas.Their performance characteristics are summarized and then compared with our previously developed electrically small Huygens rectennas that are proven to be more suitable for IoT applications.They have been tailored,for example,to achieve batteryfree IoT sensors as is demonstrated in this paper.Battery-free,wirelessly powered devices are smaller and lighter in weight in comparison to battery-powered devices.Moreover,they are environmentally friendly and,hence,have a significant societal benefit.A series of high-performance electrically small Huygens rectennas are presented including Huygens linearly-polarized(HLP)and circularly-polarized(HCP)rectennas;wirelessly powered IoT sensors based on these designs;and a dual-functional HLP rectenna and antenna system.Finally,two linear uniform HLP rectenna array systems are considered for significantly larger wireless power capture.Example arrays illustrate how they can be integrated advantageously with DC or radio frequency(RF)power-combining schemes for practical IoT applications.展开更多
随着航空航天技术的快速发展,封闭腔体内的无线能量传输(Wireless Power Transmission,WPT)技术开始受到广泛关注.基于频率控制的WPT技术,可实现对电大封闭腔体(103×λ3)内的多方位传感器进行可控和高效的无线充电.电大腔体内的电...随着航空航天技术的快速发展,封闭腔体内的无线能量传输(Wireless Power Transmission,WPT)技术开始受到广泛关注.基于频率控制的WPT技术,可实现对电大封闭腔体(103×λ3)内的多方位传感器进行可控和高效的无线充电.电大腔体内的电场分布对频率的变化敏感,利用频率变化实现对封闭腔体场分布控制.实验结果表明,在S波段的1 m3腔体最高WPT传输效率为96.6%.设计的宽带整流电路实测整流效率最高为80%,整流效率高于50%的带宽为1.65 GHz.在2.401~2.495 GHz频段实现控制双接收机的不同工作状态,展现其在航空航天器等封闭空间中为传感器无线供电的应用前景.展开更多
文摘In this paper,a novel pulse density modulation(PDM)with semi-bridgeless active rectifier(S-BAR)in inductive power transfer(IPT)system for rail vehicle is proposed.It is to reduce switching losses of the active rectifier in pickups.In the control method,the insulated-gate bipolar transistors(IGBTs)in the S-BAR are controlled by synchronous PDM signals,so that zero-voltage switching(ZVS)and zero-current switching(ZCS)can be achieved in the whole output power range.The output power is regulated by changing the pulse density(PD)of the S-BAR since the it is almost linear proportional with the PD in high quality factor of pickup side.The communication device between the primary side and pickup side is not necessary anymore.The detailed theoretical analyses of the PDM method are provided,and its advantages are shown in a 7.5kW IPT prototype for rail vehicle.The experimental results are presented to verify the analysis and demonstrate the performance.The overall efficiency of the system by PDM control is 74.2%which is improved by 4%compared with phase shift(PS)control at light load.
基金supported by TM R&D Malaysia under project number MMUE/190001.
文摘This paper presents a compact multi-band rectifier with an improved impedance matching bandwidth.It uses a combination of–matching network(MN)at Port-1,with a parallel connection of three cell branch MN at Port-2.The proposed impedance matching network(IMN)is adopted to reduce circuit complexity,to improve circuit performance,and power conversion efficiency(PCE)of the rectifier at low input power.The fabricated rectifier prototype operates at 0.92,1.82,2.1,2.46 and 2.65 GHz covering GSM/900,GSM/1800,UMTS2100,and Wi-Fi/2.45–LTE2600.The size of the compact rectifier on the PCB board is 0.13λ_(g)×0.1λ_(g).The fabricated rectifier achieved an RF-to DC(radio frequency direct current)PCE of 31.8%,24%,22.7%,and 15%,and 14.1%for−20 dBm at the five respective measured operating frequencies.The circuit attains a peak RF-to-DC PCE of 82.3%for an input power of 3 dBm at 0.92 GHz.The proposed rectifier realizes an ambient output dc voltage of 454 mV for multi-tone input signals from the two ports.The rectifier drives a bq25504-674 power management module(PMM)to achieve 1.21 V from the two-port connection.The rectifier has the ability to exploit both frequency domain through the multi-band operation with good impedance bandwidth and a spatial domain using dual-port configuration.Hence,it is a potential candidate for various applications in radio frequency energy harvesting(RFEH)system.
基金Key Laboratory of Chinese Academy of Sciences Foundation,China(No. 20190918)。
文摘A rectifier circuit for wireless energy harvesting(WEH) with a wide input power range is proposed in this paper. We build up accurate models of the diodes to improve the accuracy of the design of the rectifier. Due to the nonlinear characteristics of the diodes, a new band-stop structure is introduced to reduce the imaginary part impedance and suppress harmonics. A novel structure with double branches and an optimized λ/4 microstrip line is proposed to realize the power division ratio adjustment by the input power automatically. The proposed two branches can satisfy the two cases with input power of-20 dBm to 0 dBm and 0 dBm to 15 dBm, respectively. Here, dBm = 10 log(P mW), and P represents power. An impedance compression network(ICN) is correspondingly designed to maintain the input impedance stability over the wide input power range. A rectifier that works at 2.45 GHz is implemented. The measured results show that the highest efficiency can reach 51.5% at the output power of 0 dBm and higher than 40% at the input power of-5 dBm to 12 dBm.
基金The National High Technology Research and Development Program of China (863 Program) ( No. 2006AA12Z302)
文摘For the high resolution required in a digital interface circuit of an accelerometer used in feeble gravity measurement, a switched-capacitor (SC) sigma-delta modulator (SDM) is proposed. Based on the principle and the topology structure of the SDMs, the influence of oversampling ratio, bits of an internal quantizer and the cascaded structure on weak signal detecting precision is analyzed, and an ideal low-distortion SDM with a second-order 1-bit structure satisfying the high- resolution interface circuit of an accelerometer is designed. With the research on non-idealities of each SDM block in the SC circuit implementation and their impacts on power consumption, the realized parameters of low-power SDMs based on different bandwidths are devised and the power consumption of each SDM is estimated. Time-domain behavioral simulation is explored based on Simulink. The results demonstrate that a 21- bit resolution of the designed SDMs can be achieved on the premise of low power, and the parameters for the circuit implementation can be directed to the transistor-level circuit design.
文摘The Generalized Falk Method(GFM)for coordinate transformation,together with two model-reduction strategies based on this method,are presented for efficient coupled field-circuit simulations.Each model-reduction strategy is based on a decision to retain specific linearly-independent vectors,called trial vectors,to construct a vector basis for coordinate transformation.The reduced-order models are guaranteed to be stable and passive since the GFM is a congruence transformation of originally symmetric positive definite systems.We also show that,unlike the Pade-via-Lanczos(PVL)method,the GFM does not generate unstable positive poles while reducing the order´of circuit problems.Further,the proposed GFM is also faster when compared to methods of the type Lanczos(or Krylov)that are already widely used in circuit simulations for electrothermal and electromagnetic problems.The concept of response participation factors is introduced for the selection of the trial vectors in the proposed model-reduction methods.Further,we present methods to develop simple equivalent circuit networks for the field component of the overall field-circuit system.The implementation of these equivalent circuit networks in circuit simulators is discussed.With the proposed model-reduction strategies,significant improvement on the efficiency of the generalized Falk method is illustrated for coupled field-circuit problems.
基金supported by the University of Technology Sydney (UTS) Chancellor’s Postdoctoral Fellowship (PRO18-6147)Australian Research Council (ARC) Discovery Early Career Researcher Award (DECRA) (PRO20-9959)
文摘Far-field wireless power transfer(WPT)is a major breakthrough technology that will enable the many anticipated ubiquitous Internet of Things(IoT)applications associated with fifth generation(5G),sixth generation(6G),and beyond wireless ecosystems.Rectennas,which are the combination of rectifying circuits and antennas,are the most critical components in far-field WPT systems.However,compact application devices require even smaller integrated rectennas that simultaneously have large electromagnetic wave capture capabilities,high alternating current(AC)-to-direct current(DC)(AC-to-DC)conversion efficiencies,and facilitate a multifunctional wireless performance.This paper reviews various rectenna miniaturization techniques such as meandered planar inverted-F antenna(PIFA)rectennas;miniaturized monopole-and dipole-based rectennas;fractal loop and patch rectennas;dielectric-loaded rectennas;and electrically small near-field resonant parasitic rectennas.Their performance characteristics are summarized and then compared with our previously developed electrically small Huygens rectennas that are proven to be more suitable for IoT applications.They have been tailored,for example,to achieve batteryfree IoT sensors as is demonstrated in this paper.Battery-free,wirelessly powered devices are smaller and lighter in weight in comparison to battery-powered devices.Moreover,they are environmentally friendly and,hence,have a significant societal benefit.A series of high-performance electrically small Huygens rectennas are presented including Huygens linearly-polarized(HLP)and circularly-polarized(HCP)rectennas;wirelessly powered IoT sensors based on these designs;and a dual-functional HLP rectenna and antenna system.Finally,two linear uniform HLP rectenna array systems are considered for significantly larger wireless power capture.Example arrays illustrate how they can be integrated advantageously with DC or radio frequency(RF)power-combining schemes for practical IoT applications.