A small-signal equivalent circuit model and the ted. The equivalent lumped circuit, which takes the main extraction techniques for photodetector chips are presen- factors that limit a photodetector's RF performance i...A small-signal equivalent circuit model and the ted. The equivalent lumped circuit, which takes the main extraction techniques for photodetector chips are presen- factors that limit a photodetector's RF performance into consideration,is first determined based on the device's physical structure. The photodetector's S parameters are then on-wafer measured, and the measured raw data are processed with further calibration. A genetic algorithm is used to fit the measured data, thereby allowing us to calculate each parameter value of the model. Experimental resuits show that the modeled parameters are well matched to the measurements in a frequency range from 130MHz to 20GHz, and the proposed method is proved feasible. This model can give an exact description of the photodetector chip's high frequency performance,which enables an effective circuit-level prediction for photodetector and optoelectronic integrated circuits.展开更多
On the basis of analysis on the temperature monitoring methods for high voltage devices, a new type of fiber optic sensor structure with reference channel is given. And the operation principle of fiber optic sensor is...On the basis of analysis on the temperature monitoring methods for high voltage devices, a new type of fiber optic sensor structure with reference channel is given. And the operation principle of fiber optic sensor is analysed at large based on the absorption of semiconductor chip. The mathematical model of both devices and the whole system are also given. It is proved by the experiment that this mathematical model is reliable.展开更多
To enhance the communication quality of Open Flow controlled all-optical networks,an optical signal-to-noise ratio comprehensive-awareness(OSNR-CA) model based lightpath control scheme is proposed.This approach transf...To enhance the communication quality of Open Flow controlled all-optical networks,an optical signal-to-noise ratio comprehensive-awareness(OSNR-CA) model based lightpath control scheme is proposed.This approach transforms main physical-layer optical impairments into OSNR value,and takes this comprehensive OSNR value of the optical signal along the lightpath into consideration,when establishing the lightpath for the connection request using OpenFlow protocol.Moreover,the proposed scheme makes full advantages of the OSNR monitoring function in each node,and assigns the lightpath according to the comprehensive-OSNR value by extending messages of Open Flow protocol,in order to guarantee the reliable establishment of the lightpath.The simulation results show that the proposed scheme has better performance in terms of packet loss rate and lightpath establishment time.展开更多
An improved method is proposed to simulate the scintillation introduced by the turbulence, based on the finite Markov state model. As a contrast to the literatures, uniformly distributed variables take place during a ...An improved method is proposed to simulate the scintillation introduced by the turbulence, based on the finite Markov state model. As a contrast to the literatures, uniformly distributed variables take place during a certain state, which contributes to equivalent simulation of the intensity fluctuations with fewer states than the traditional Markov model. It's also discovered that the proposed Markov model with 20 states provides a satisfactory approximation to the experimental results in the auto-covariance analysis. Moreover, the outage probability and mean fading time are more accurate than those of the traditional Markov model with equivalent states.展开更多
In view of the universality of the parallel connection of solar cells and their mismatch problem, in the present paper, we select two shunt solar cells (connected in parallel) as our research object, and use the equiv...In view of the universality of the parallel connection of solar cells and their mismatch problem, in the present paper, we select two shunt solar cells (connected in parallel) as our research object, and use the equivalent one-diode circuit of the solar cell and the analysis of the two-body model. At first, the equations of current and voltage are deduced from the related electrical laws and the circuit diagram of the two solar cells connected in parallel. Then, according to the experimentally measured data of typical single-crystalline silicon solar cells (125 mm×125 mm), we select the appropriate simulation parameters. Following this, by using the photo-generated current, the shunt resistance, and the serial resistance of one of the shunt solar cells and the load resistance as independent variables, in turn, the changing characteristics of each branch current in the two shunt solar cells are numerically discussed and analyzed for these four cases for the first time. At the same time, we provide a simple physical explanation for the modeling results. Our analyses show that these parameters have different impacts on the internal currents of solar cells connected in parallel. These results provide a reference to solve the problem of connecting solar cells and to develop higher efficiency solar cells and systems. Meanwhile, the results will contribute to a better comprehension of the reasons for efficiency loss of solar cells and systems, and deepen the understanding of the electrical of solar cells behavior for high performance photovoltaic applications.展开更多
文摘A small-signal equivalent circuit model and the ted. The equivalent lumped circuit, which takes the main extraction techniques for photodetector chips are presen- factors that limit a photodetector's RF performance into consideration,is first determined based on the device's physical structure. The photodetector's S parameters are then on-wafer measured, and the measured raw data are processed with further calibration. A genetic algorithm is used to fit the measured data, thereby allowing us to calculate each parameter value of the model. Experimental resuits show that the modeled parameters are well matched to the measurements in a frequency range from 130MHz to 20GHz, and the proposed method is proved feasible. This model can give an exact description of the photodetector chip's high frequency performance,which enables an effective circuit-level prediction for photodetector and optoelectronic integrated circuits.
文摘On the basis of analysis on the temperature monitoring methods for high voltage devices, a new type of fiber optic sensor structure with reference channel is given. And the operation principle of fiber optic sensor is analysed at large based on the absorption of semiconductor chip. The mathematical model of both devices and the whole system are also given. It is proved by the experiment that this mathematical model is reliable.
基金supported by the National High Technical Research and Development Program of China(863 Program)(No.2012AA050804)
文摘To enhance the communication quality of Open Flow controlled all-optical networks,an optical signal-to-noise ratio comprehensive-awareness(OSNR-CA) model based lightpath control scheme is proposed.This approach transforms main physical-layer optical impairments into OSNR value,and takes this comprehensive OSNR value of the optical signal along the lightpath into consideration,when establishing the lightpath for the connection request using OpenFlow protocol.Moreover,the proposed scheme makes full advantages of the OSNR monitoring function in each node,and assigns the lightpath according to the comprehensive-OSNR value by extending messages of Open Flow protocol,in order to guarantee the reliable establishment of the lightpath.The simulation results show that the proposed scheme has better performance in terms of packet loss rate and lightpath establishment time.
文摘An improved method is proposed to simulate the scintillation introduced by the turbulence, based on the finite Markov state model. As a contrast to the literatures, uniformly distributed variables take place during a certain state, which contributes to equivalent simulation of the intensity fluctuations with fewer states than the traditional Markov model. It's also discovered that the proposed Markov model with 20 states provides a satisfactory approximation to the experimental results in the auto-covariance analysis. Moreover, the outage probability and mean fading time are more accurate than those of the traditional Markov model with equivalent states.
基金supported by the National Natural Science Foundation of China (Grant No. 51561031)the Natural Science Foundation of Guangxi Province (Grant No. 2015GXNSFBA139240)+1 种基金Open Foundation of Guangxi Colleges and Universities Key Laboratory of Complex System Optimization and Large Data Processing (Grant No. 2015CSOBD0102)the Highlevel Personnel Scientific Research Funds of Yulin Normal University (Grant No. G20150001)
文摘In view of the universality of the parallel connection of solar cells and their mismatch problem, in the present paper, we select two shunt solar cells (connected in parallel) as our research object, and use the equivalent one-diode circuit of the solar cell and the analysis of the two-body model. At first, the equations of current and voltage are deduced from the related electrical laws and the circuit diagram of the two solar cells connected in parallel. Then, according to the experimentally measured data of typical single-crystalline silicon solar cells (125 mm×125 mm), we select the appropriate simulation parameters. Following this, by using the photo-generated current, the shunt resistance, and the serial resistance of one of the shunt solar cells and the load resistance as independent variables, in turn, the changing characteristics of each branch current in the two shunt solar cells are numerically discussed and analyzed for these four cases for the first time. At the same time, we provide a simple physical explanation for the modeling results. Our analyses show that these parameters have different impacts on the internal currents of solar cells connected in parallel. These results provide a reference to solve the problem of connecting solar cells and to develop higher efficiency solar cells and systems. Meanwhile, the results will contribute to a better comprehension of the reasons for efficiency loss of solar cells and systems, and deepen the understanding of the electrical of solar cells behavior for high performance photovoltaic applications.