This paper examines the definition of MPT-SBSP and implementation model of such technology.It surveys the latest development and affirms the feasibility and a bright future of this technology,emphasizing the existing ...This paper examines the definition of MPT-SBSP and implementation model of such technology.It surveys the latest development and affirms the feasibility and a bright future of this technology,emphasizing the existing issues must be solved by more educated individuals and organizations for the early realization of this"beyond-the-realm-of-cost"technology.Because once this technology is successfully applied in large-scale,humans won’t have to worry about the energy crisis in the future.展开更多
Circularly polarized rectennas operating at X-band are studied in this paper. The quasi-square patches fed by aperture coupling are used as the circularly polarized receiving antennas, which are easily matched and int...Circularly polarized rectennas operating at X-band are studied in this paper. The quasi-square patches fed by aperture coupling are used as the circularly polarized receiving antennas, which are easily matched and integrated with the circuits of rectennas. The double-layer structure not only minimizes the size of the rectennas but also decreases the effects of the circuits on the an- tenna. The receiving elements have broader bandwidth and higher gain than the single-layer patches. Two rectennas operating at 10GHz are designed, fabricated and measured. The voltage of 3.86V on a load of 200? is measured and a high RF-DC conversion efficiency of 75% is obtained at 9.98GHz. It is convenient for this kind of rectennas to form large arrays for high power applications.展开更多
This work presents an optimal design method of antenna aperture illumination for microwave power transmission with an annular collection area.The objective is to maximize the ratio of the power radiated on the annular...This work presents an optimal design method of antenna aperture illumination for microwave power transmission with an annular collection area.The objective is to maximize the ratio of the power radiated on the annular collection area to the total transmitted power.By formulating the aperture amplitude distribution through a summation of a special set of series,the optimal design problem can be reduced to finding the maximum ratio of two real quadratic forms.Based on the theory of matrices,the solution to the formulated optimization problem is to determine the largest characteristic value and its associated characteristic vector.To meet security requirements,the peak radiation levels outside the receiving area are considered to be extra constraints.A hybrid grey wolf optimizer and Nelder–Mead simplex method is developed to deal with this constrained optimization problem.In order to demonstrate the effectiveness of the proposed method,numerical experiments on continuous apertures are conducted;then,discrete arrays of isotropic elements are employed to validate the correctness of the optimized results.Finally,patch arrays are adopted to further verify the validity of the proposed method.展开更多
An experimental study is conducted on several retro-reflective beamforming schemes for wireless power transmission to multiple wireless power receivers(referred to herein as“targets”).The experimental results demons...An experimental study is conducted on several retro-reflective beamforming schemes for wireless power transmission to multiple wireless power receivers(referred to herein as“targets”).The experimental results demonstrate that,when multiple targets broadcast continuous-wave pilot signals at respective frequencies,a retro-reflective wireless power transmitter is capable of generating multiple wireless power beams aiming at the respective targets as long as the multiple pilot signals are explicitly separated from one another by the wireless power transmitter.However,various practical complications are identified when the pilot signals of multiple targets are not appropriately differentiated from each other by the wireless power transmitter.Specifically,when multiple pilot signals are considered to be carried by the same frequency,the wireless power transmission performance becomes heavily dependent on the interaction among the pilot signals,which is highly undesirable in practice.In conclusion,it is essential for a retro-reflective wireless power transmitter to explicitly discriminate multiple targets’pilot signals among each other.展开更多
Retro reflective beamforming technique has the potential of enabling efficient wireless power transmission over long distance(on the order of meters and even kilometers).In retro reflective beamforming,wireless power ...Retro reflective beamforming technique has the potential of enabling efficient wireless power transmission over long distance(on the order of meters and even kilometers).In retro reflective beamforming,wireless power transmission is guided by pilot signal:Based upon pilot signal broadcasted by a wireless power receiver,a wireless power transmitter delivers focused microwave power beam(s)onto the location of wireless power receiver.When the wireless power receiver’s location is not fixed or when the wireless power receiver’s location is unknown to the wireless power transmitter,the microwave power beam would follow the wireless power receiver’s location dynamically as long as the wireless power receiver broadcasts pilot signal periodically.This paper reviews our research endeavors in recent years on retro reflective beamforming technique targeting three applications:(1)wireless charging for low power mobile/portable electronic devices,(2)space solar power satellites(SSPS)application,and(3)wireless charging in fully enclosed space.The feasibility and potential of retro reflective beamforming technique with applications in wireless power transmission are demonstrated by some preliminary experimental results.展开更多
This study proposes a method for maximizing the beam collection efficiency(BCE)for a microwave power transmission system with multiple receiving targets in the radiative near-field region.The electric and magnetic fie...This study proposes a method for maximizing the beam collection efficiency(BCE)for a microwave power transmission system with multiple receiving targets in the radiative near-field region.The electric and magnetic fields of the transmitting array are calculated via the superposition principle.Through theoretical derivation,the BCE maximization problem is simplified into finding the maximum ratio of two real quadratic forms.Based on the theory of matrices,the optimal BCE and its corresponding excitations of the transmitting array can be determined by finding the largest characteristic value and its associated characteristic vector.In practice,the required power for multiple receiving targets may be different.To meet this requirement,a BCE optimization model is established,considering the constraints of the problem of allocable power for each receiving target.A hybrid grey wolf optimizer and Nelder-Mead simplex method is adopted to address the optimization problem.To verify the effectiveness of the proposed method,numerical experiments on focusing the power radiated on two parallel receiving targets are conducted first.Then,two rotating receiving targets are employed to show its universality.Finally,three and four receiving targets are adopted to further evaluate the validity of the proposed method.展开更多
An X-band magnetically insulated transmission line oscillator （MILO） is designed and investigated numerically and experimentally for the first time. The X-band MILO is optimized in detail with KARAT code. In simulat...An X-band magnetically insulated transmission line oscillator （MILO） is designed and investigated numerically and experimentally for the first time. The X-band MILO is optimized in detail with KARAT code. In simulation, the X-band MILO, driven by a 720 kV, 53 kA electron beam, comes to a nonlinear steady state in 4.0 ns. High-power microwaves （HPM） of TEM mode is generated with an average power of 4.1 GW, a frequency of 9.3 GHz, and power conversion efficiency of 10.870 in durations of 0-40 ns. The device is fabricated according to the simulation results. In experiments, when the voltage is 400 kV and the current is 50 kA, the radiated microwave power reaches about 110 MW and the dominating frequency is 9.7GHz. Because the surfaces of the cathode end and the beam dump are destroyed, the diode voltage cannot increase continuously. However, when the diode voltage is 400 kV, the average power output is obtained to be 700 MW in simulation. The impedance of the device is clearly smaller than the simulation prediction. Moreover, the duration of the microwave pulse is obviously shorter than that of the current pulse. The experimental results are greatly different from the simulation predictions. The preliminary analyses show that the generations of the anode plasma, the cathode flare and the anode flare are the essential cause for the remarkable deviation of the experimental results from the simulation predictions.展开更多
This paper puts forward a novel magnetically insulated transmission line oscillator （MILO） for the first time which takes a modified HEM11 mode as its main interaction mode. The excitation of the oscillation mode is...This paper puts forward a novel magnetically insulated transmission line oscillator （MILO） for the first time which takes a modified HEM11 mode as its main interaction mode. The excitation of the oscillation mode is made possible by carefully adjusting the arrangements of each resonant cavity in a two-dimensional （2-D） slow wave structure. The high frequency characteristics are analyzed and a PIC simulation is carried out; the detailed results are discussed to get a better understanding of this new MILO. Employing an electron beam of about 441 kV and 39.7 kA, it finds that the modified HEM11 mode MILO generates a high power microwave output of about 1.47 GW at 1.45 GHz. The power conversion efficiency is about 8.4% and the generated microwave is in a TEll-like circularly polarized mode; its polarization direction is decided by the rotation direction of the SWS.展开更多
A novel magnetically insulated transmission line oscillator （MILO） in which a modified HEM11 mode is taken as its main interaction mode （HEM11 mode MILO） is simulated and experimented in this paper. The excitation...A novel magnetically insulated transmission line oscillator （MILO） in which a modified HEM11 mode is taken as its main interaction mode （HEM11 mode MILO） is simulated and experimented in this paper. The excitation of the oscillation mode is made possible by carefully adjusting the arrangement of each resonant cavity in a two-dimensional slow wave structure. The special feature of such a device is that in the slow-wave-structure region, the interaction mode is HEM11 mode which is a TM-like one that could interact with electron beams effectively; and in the coaxial output region, the microwave mode is TE11 mode which has a favourable field density pattern to be directly radiated. Employing an electron beam of about 441 kV and 39.7 kA, the HEM11 mode MILO generates a high power microwave output of about 1.47 GW at 1.45 GHz in particle-in-cell simulation. The power conversion efficiency is about 8.4 % and the generated microwave is in a TEll-like circular polarization mode. In a preliminary experiment investigation, high power microwave is detected from the device with a frequency of 1.46 GHz, an output energy of 43 J 47 J, and a pulse duration of 44 ns-49 ns when the input voltage is 430 kV450 kV, and the diode current is 37 kA-39 kA.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This paper examines the definition of MPT-SBSP and implementation model of such technology.It surveys the latest development and affirms the feasibility and a bright future of this technology,emphasizing the existing issues must be solved by more educated individuals and organizations for the early realization of this"beyond-the-realm-of-cost"technology.Because once this technology is successfully applied in large-scale,humans won’t have to worry about the energy crisis in the future.
基金Supported by the Development Fund of Shanghai Edu-cation Committee and Shanghai Leading Academic Dis-cipline Project (No.T0102)
文摘Circularly polarized rectennas operating at X-band are studied in this paper. The quasi-square patches fed by aperture coupling are used as the circularly polarized receiving antennas, which are easily matched and integrated with the circuits of rectennas. The double-layer structure not only minimizes the size of the rectennas but also decreases the effects of the circuits on the an- tenna. The receiving elements have broader bandwidth and higher gain than the single-layer patches. Two rectennas operating at 10GHz are designed, fabricated and measured. The voltage of 3.86V on a load of 200? is measured and a high RF-DC conversion efficiency of 75% is obtained at 9.98GHz. It is convenient for this kind of rectennas to form large arrays for high power applications.
基金supported in part by the National Key Research and Development Program of China(2021YFB3900300)in part by the National Natural Science Foundation of China(62201416)+2 种基金in part by the Fundamental Research Funds for the Central Universities(QTZX23070)in part by the Qin Chuang Yuan High-Level Innovative and Entrepreneurial Talents Project(QCYRCXM-2022-314)in part by Singapore Ministry of Education Academic Research Fund Tier 1。
文摘This work presents an optimal design method of antenna aperture illumination for microwave power transmission with an annular collection area.The objective is to maximize the ratio of the power radiated on the annular collection area to the total transmitted power.By formulating the aperture amplitude distribution through a summation of a special set of series,the optimal design problem can be reduced to finding the maximum ratio of two real quadratic forms.Based on the theory of matrices,the solution to the formulated optimization problem is to determine the largest characteristic value and its associated characteristic vector.To meet security requirements,the peak radiation levels outside the receiving area are considered to be extra constraints.A hybrid grey wolf optimizer and Nelder–Mead simplex method is developed to deal with this constrained optimization problem.In order to demonstrate the effectiveness of the proposed method,numerical experiments on continuous apertures are conducted;then,discrete arrays of isotropic elements are employed to validate the correctness of the optimized results.Finally,patch arrays are adopted to further verify the validity of the proposed method.
基金supported in part by the National Natural Science Foundation of China(61871220)the Natural Science Foundation of Jiangsu Province(BK20201293)。
文摘An experimental study is conducted on several retro-reflective beamforming schemes for wireless power transmission to multiple wireless power receivers(referred to herein as“targets”).The experimental results demonstrate that,when multiple targets broadcast continuous-wave pilot signals at respective frequencies,a retro-reflective wireless power transmitter is capable of generating multiple wireless power beams aiming at the respective targets as long as the multiple pilot signals are explicitly separated from one another by the wireless power transmitter.However,various practical complications are identified when the pilot signals of multiple targets are not appropriately differentiated from each other by the wireless power transmitter.Specifically,when multiple pilot signals are considered to be carried by the same frequency,the wireless power transmission performance becomes heavily dependent on the interaction among the pilot signals,which is highly undesirable in practice.In conclusion,it is essential for a retro-reflective wireless power transmitter to explicitly discriminate multiple targets’pilot signals among each other.
基金supported in part by the National Natural Science Foundations of China (Nos. 61871220, 61471195, 61628106)the United States National Science Foundation (Nos. ECCS 1303142, ECCS 1503600)
文摘Retro reflective beamforming technique has the potential of enabling efficient wireless power transmission over long distance(on the order of meters and even kilometers).In retro reflective beamforming,wireless power transmission is guided by pilot signal:Based upon pilot signal broadcasted by a wireless power receiver,a wireless power transmitter delivers focused microwave power beam(s)onto the location of wireless power receiver.When the wireless power receiver’s location is not fixed or when the wireless power receiver’s location is unknown to the wireless power transmitter,the microwave power beam would follow the wireless power receiver’s location dynamically as long as the wireless power receiver broadcasts pilot signal periodically.This paper reviews our research endeavors in recent years on retro reflective beamforming technique targeting three applications:(1)wireless charging for low power mobile/portable electronic devices,(2)space solar power satellites(SSPS)application,and(3)wireless charging in fully enclosed space.The feasibility and potential of retro reflective beamforming technique with applications in wireless power transmission are demonstrated by some preliminary experimental results.
基金the national Natural ScienceFoundation of China(No.62201416&No.U2241247)the Fundamental Research Funds for the Central Universities(No.QTZX23070&QTZX24002)+1 种基金the Qin Chuang Yuan High-Level Innovative and Entrepreneurial Talents(No.QCYRCXM-2022-314)the Natural Science Basic Research Program ofShaanxi(No.2022JC-DW-01).
文摘This study proposes a method for maximizing the beam collection efficiency(BCE)for a microwave power transmission system with multiple receiving targets in the radiative near-field region.The electric and magnetic fields of the transmitting array are calculated via the superposition principle.Through theoretical derivation,the BCE maximization problem is simplified into finding the maximum ratio of two real quadratic forms.Based on the theory of matrices,the optimal BCE and its corresponding excitations of the transmitting array can be determined by finding the largest characteristic value and its associated characteristic vector.In practice,the required power for multiple receiving targets may be different.To meet this requirement,a BCE optimization model is established,considering the constraints of the problem of allocable power for each receiving target.A hybrid grey wolf optimizer and Nelder-Mead simplex method is adopted to address the optimization problem.To verify the effectiveness of the proposed method,numerical experiments on focusing the power radiated on two parallel receiving targets are conducted first.Then,two rotating receiving targets are employed to show its universality.Finally,three and four receiving targets are adopted to further evaluate the validity of the proposed method.
基金supported by the Chinese National Natural Science Foundation (Grant No 10675168)Innovation Fund of Graduate School of the National University of Defense Technology of China
文摘An X-band magnetically insulated transmission line oscillator （MILO） is designed and investigated numerically and experimentally for the first time. The X-band MILO is optimized in detail with KARAT code. In simulation, the X-band MILO, driven by a 720 kV, 53 kA electron beam, comes to a nonlinear steady state in 4.0 ns. High-power microwaves （HPM） of TEM mode is generated with an average power of 4.1 GW, a frequency of 9.3 GHz, and power conversion efficiency of 10.870 in durations of 0-40 ns. The device is fabricated according to the simulation results. In experiments, when the voltage is 400 kV and the current is 50 kA, the radiated microwave power reaches about 110 MW and the dominating frequency is 9.7GHz. Because the surfaces of the cathode end and the beam dump are destroyed, the diode voltage cannot increase continuously. However, when the diode voltage is 400 kV, the average power output is obtained to be 700 MW in simulation. The impedance of the device is clearly smaller than the simulation prediction. Moreover, the duration of the microwave pulse is obviously shorter than that of the current pulse. The experimental results are greatly different from the simulation predictions. The preliminary analyses show that the generations of the anode plasma, the cathode flare and the anode flare are the essential cause for the remarkable deviation of the experimental results from the simulation predictions.
基金Project supported by the Science Foundation of the China Academy of Engineering Physics (Grant No 2008B0402046)
文摘This paper puts forward a novel magnetically insulated transmission line oscillator （MILO） for the first time which takes a modified HEM11 mode as its main interaction mode. The excitation of the oscillation mode is made possible by carefully adjusting the arrangements of each resonant cavity in a two-dimensional （2-D） slow wave structure. The high frequency characteristics are analyzed and a PIC simulation is carried out; the detailed results are discussed to get a better understanding of this new MILO. Employing an electron beam of about 441 kV and 39.7 kA, it finds that the modified HEM11 mode MILO generates a high power microwave output of about 1.47 GW at 1.45 GHz. The power conversion efficiency is about 8.4% and the generated microwave is in a TEll-like circularly polarized mode; its polarization direction is decided by the rotation direction of the SWS.
文摘A novel magnetically insulated transmission line oscillator （MILO） in which a modified HEM11 mode is taken as its main interaction mode （HEM11 mode MILO） is simulated and experimented in this paper. The excitation of the oscillation mode is made possible by carefully adjusting the arrangement of each resonant cavity in a two-dimensional slow wave structure. The special feature of such a device is that in the slow-wave-structure region, the interaction mode is HEM11 mode which is a TM-like one that could interact with electron beams effectively; and in the coaxial output region, the microwave mode is TE11 mode which has a favourable field density pattern to be directly radiated. Employing an electron beam of about 441 kV and 39.7 kA, the HEM11 mode MILO generates a high power microwave output of about 1.47 GW at 1.45 GHz in particle-in-cell simulation. The power conversion efficiency is about 8.4 % and the generated microwave is in a TEll-like circular polarization mode. In a preliminary experiment investigation, high power microwave is detected from the device with a frequency of 1.46 GHz, an output energy of 43 J 47 J, and a pulse duration of 44 ns-49 ns when the input voltage is 430 kV450 kV, and the diode current is 37 kA-39 kA.
