To improve the reliability of the light emitting diode(LED)signal lamp filament current monitoring alarm instrument for metro systems,a new type of hot standby online monitoring apparatus was developed which is based ...To improve the reliability of the light emitting diode(LED)signal lamp filament current monitoring alarm instrument for metro systems,a new type of hot standby online monitoring apparatus was developed which is based on synchronous transmission data(STD)bus technology.In this system,a double hot standby mode can be achieved by adopting bus arbitration.In addition,to detect the effective value of alternating current which is from 0 to 200 mA in the signal lamp lighting circuit,a precision rectifier signal conditioning circuit and an isolated acquisition circuit were designed.This new type of alarm instrument has high detection accuracy and could meet the functional requirements for metro signal systems after comparing it with some industry products that were applied on the spot.展开更多
The operating circuits for LED (light emitting diode) lamp composed of diodes and DC capacitors only are proposed. The proposed circuit is based on a double-voltage rectifier circuit and a Cockcroft-Walton circuit. ...The operating circuits for LED (light emitting diode) lamp composed of diodes and DC capacitors only are proposed. The proposed circuit is based on a double-voltage rectifier circuit and a Cockcroft-Walton circuit. The circuit can operate LED without flicker, and is free from switching noise since high frequency switching circuit is not used. To replace an AC capacitor by a DC capacitor for the ballast, a diode is connected across the capacitor in parallel, and the operating voltage of LED unit is kept at the value greater than the peak voltage of the input power source. The circuit realizes high efficiency and high input power factor compared with the operating circuits on the market. Cockcroft-Walton-type circuit can operate many LED devices in series connection. Series connection is preferable for fabricating LED unit of a constant voltage characteristic. Moreover, fairly flat waveform of LED operating current is realized by Cockcrofl-Walton-type circuit, even though capacitor ballast is used.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
The unique features of ambipolar two-dimensional materials open up a great opportunity to build gate-programmable devices for reconfigurable circuit applications,e.g.,PN junctions for rectifier circuits.However,curren...The unique features of ambipolar two-dimensional materials open up a great opportunity to build gate-programmable devices for reconfigurable circuit applications,e.g.,PN junctions for rectifier circuits.However,current-reported rectifier circuits usually consist of one gate-programmable PN junction as the rectifier and one resistor as the load,which are not conductive to voltage output and large-scale integration.Here we propose an approach of complementary gate-programmable PN junctions to assemble reconfigurable rectifier circuit,which include two symmetric back-to-back black phosphorus(BP)/hexagonal boron nitride(h-BN)/graphene heterostructured semi-gate field-effect transistors(FETs)and perform complementary NP and PN junction like complementary metal-oxide-semiconductor(CMOS)circuit.The investigation exhibits that the circuit can effectively reconfigure the circuit with/without rectifying ability,and can process alternating current(AC)signals with the frequency prior 1 KHz and reconfiguration speed up to 25μs.We also achieve the reconfigurable rectifier circuit memory via complementary semi-floating gate FETs configuration.The complementary configuration here should be of low output impedance and low static power consumption,being beneficial for effective voltage output and large-scale integration.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
Miniaturized mobile electronic devices have aroused great attention due to their convenience to daily life. However, they still face a problem that power supply from the conventional cell needs to be regularly charged...Miniaturized mobile electronic devices have aroused great attention due to their convenience to daily life. However, they still face a problem that power supply from the conventional cell needs to be regularly charged or replaced. Portable electricity supply collecting energy from environment is highly desired. Herein, a highly flexible and stretchable Miura folding based triboelectric nanogenerator (MF-TENG) is prepared by using flexible polyethylene terephthalate (PET) as a folding substrate with a double working side design, specifically one side as the main TENG (M-TENG) and other side as the excitation TENG (E-TENG). The E-TENG supplements charge to M-TENG by a half-wave rectifier circuit. This design increases the TENG working area and reduces its volume. The output performance of the TENG based on Miura folding with charge excitation called MF-CE-TENG is greatly boosted. The optimal output charge and maximum peak power of MF-CE-TENG achieves 1.54 µC and 5.17 mW at 1 Hz, respectively, which is 4.61 and 10.55 times as much as that of MF-TENG without charge excitation. To demonstrate its applications, the MF-CE-TENG is used to light up 456 LEDs brightly and charge a 100 µF capacitor to 6.07 V in 5 min. A calculator and a temperature-humidity sensor work normally powered by MF-CE-TENG with an energy management module. This work provides a new strategy to enhance the output energy of Miura folding TENG by applying a charge excitation mode for the first time, which might be an effective approach to be used in other TENGs.展开更多
A common-gate bootstrapped CMOS rectifier dedicated for VHF(very high frequency) isolated DCDC converter is proposed.It uses common-gate bootstrapped technique to compensate the power loss due to the threshold volta...A common-gate bootstrapped CMOS rectifier dedicated for VHF(very high frequency) isolated DCDC converter is proposed.It uses common-gate bootstrapped technique to compensate the power loss due to the threshold voltage,and to solve the reflux problem in the conventional rectifier circuit.As a result,it improves the power conversion efficiency(PCE) and voltage conversion ratio(VCR).The design saves almost 90%of the area compared to a previously reported double capacitor structure.In addition,we compare the previous rectifier with the proposed common-gate bootstrapped rectifier in the case of the same area;simulation results show that the PCE and VCR of the proposed structure are superior to other structures.The proposed common-gate bootstrapped rectifier was fabricated by using CSMC 0.5 μm BCD process.The measured maximum PCE is 86%and VCR achieves 77%at the operating frequency of 20 MHz.The average PCE is about 79%and average VCR achieves71%in the frequency range of 30-70 MHz.Measured PCE and VCR have been improved compared to previous results.展开更多
文摘To improve the reliability of the light emitting diode(LED)signal lamp filament current monitoring alarm instrument for metro systems,a new type of hot standby online monitoring apparatus was developed which is based on synchronous transmission data(STD)bus technology.In this system,a double hot standby mode can be achieved by adopting bus arbitration.In addition,to detect the effective value of alternating current which is from 0 to 200 mA in the signal lamp lighting circuit,a precision rectifier signal conditioning circuit and an isolated acquisition circuit were designed.This new type of alarm instrument has high detection accuracy and could meet the functional requirements for metro signal systems after comparing it with some industry products that were applied on the spot.
文摘The operating circuits for LED (light emitting diode) lamp composed of diodes and DC capacitors only are proposed. The proposed circuit is based on a double-voltage rectifier circuit and a Cockcroft-Walton circuit. The circuit can operate LED without flicker, and is free from switching noise since high frequency switching circuit is not used. To replace an AC capacitor by a DC capacitor for the ballast, a diode is connected across the capacitor in parallel, and the operating voltage of LED unit is kept at the value greater than the peak voltage of the input power source. The circuit realizes high efficiency and high input power factor compared with the operating circuits on the market. Cockcroft-Walton-type circuit can operate many LED devices in series connection. Series connection is preferable for fabricating LED unit of a constant voltage characteristic. Moreover, fairly flat waveform of LED operating current is realized by Cockcrofl-Walton-type circuit, even though capacitor ballast is used.
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Authors acknowledge the financial supports from the Ministry of Science and Technology of China(No.2018YFE0118300)the National Key Research and Development Program of China(No.2018YFA0703703)+1 种基金the State Key Laboratory of ASIC&System(No.2021MS003)the Science and Technology Commission of Shanghai Municipality(No.20501130100).
文摘The unique features of ambipolar two-dimensional materials open up a great opportunity to build gate-programmable devices for reconfigurable circuit applications,e.g.,PN junctions for rectifier circuits.However,current-reported rectifier circuits usually consist of one gate-programmable PN junction as the rectifier and one resistor as the load,which are not conductive to voltage output and large-scale integration.Here we propose an approach of complementary gate-programmable PN junctions to assemble reconfigurable rectifier circuit,which include two symmetric back-to-back black phosphorus(BP)/hexagonal boron nitride(h-BN)/graphene heterostructured semi-gate field-effect transistors(FETs)and perform complementary NP and PN junction like complementary metal-oxide-semiconductor(CMOS)circuit.The investigation exhibits that the circuit can effectively reconfigure the circuit with/without rectifying ability,and can process alternating current(AC)signals with the frequency prior 1 KHz and reconfiguration speed up to 25μs.We also achieve the reconfigurable rectifier circuit memory via complementary semi-floating gate FETs configuration.The complementary configuration here should be of low output impedance and low static power consumption,being beneficial for effective voltage output and large-scale integration.
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.
基金This work was supported by the National Natural Science Foundation of China(No.52073037)the Fundamental Research Funds for the Central Universities(No.2019CDXZWL001)Chongqing graduate tutor team construction project(No.ydstd1832).
文摘Miniaturized mobile electronic devices have aroused great attention due to their convenience to daily life. However, they still face a problem that power supply from the conventional cell needs to be regularly charged or replaced. Portable electricity supply collecting energy from environment is highly desired. Herein, a highly flexible and stretchable Miura folding based triboelectric nanogenerator (MF-TENG) is prepared by using flexible polyethylene terephthalate (PET) as a folding substrate with a double working side design, specifically one side as the main TENG (M-TENG) and other side as the excitation TENG (E-TENG). The E-TENG supplements charge to M-TENG by a half-wave rectifier circuit. This design increases the TENG working area and reduces its volume. The output performance of the TENG based on Miura folding with charge excitation called MF-CE-TENG is greatly boosted. The optimal output charge and maximum peak power of MF-CE-TENG achieves 1.54 µC and 5.17 mW at 1 Hz, respectively, which is 4.61 and 10.55 times as much as that of MF-TENG without charge excitation. To demonstrate its applications, the MF-CE-TENG is used to light up 456 LEDs brightly and charge a 100 µF capacitor to 6.07 V in 5 min. A calculator and a temperature-humidity sensor work normally powered by MF-CE-TENG with an energy management module. This work provides a new strategy to enhance the output energy of Miura folding TENG by applying a charge excitation mode for the first time, which might be an effective approach to be used in other TENGs.
文摘A common-gate bootstrapped CMOS rectifier dedicated for VHF(very high frequency) isolated DCDC converter is proposed.It uses common-gate bootstrapped technique to compensate the power loss due to the threshold voltage,and to solve the reflux problem in the conventional rectifier circuit.As a result,it improves the power conversion efficiency(PCE) and voltage conversion ratio(VCR).The design saves almost 90%of the area compared to a previously reported double capacitor structure.In addition,we compare the previous rectifier with the proposed common-gate bootstrapped rectifier in the case of the same area;simulation results show that the PCE and VCR of the proposed structure are superior to other structures.The proposed common-gate bootstrapped rectifier was fabricated by using CSMC 0.5 μm BCD process.The measured maximum PCE is 86%and VCR achieves 77%at the operating frequency of 20 MHz.The average PCE is about 79%and average VCR achieves71%in the frequency range of 30-70 MHz.Measured PCE and VCR have been improved compared to previous results.