Constructing a photoconductive semiconductor switch (PCSS)-metal coil structure, we discovered anew phenomenon of electromagnetic oscillation in vanadium-compensation semi-insulating (VCSI) PCSS. Here thePCSS responds...Constructing a photoconductive semiconductor switch (PCSS)-metal coil structure, we discovered anew phenomenon of electromagnetic oscillation in vanadium-compensation semi-insulating (VCSI) PCSS. Here thePCSS responds to laser pulse and high-voltage signal while the metal coil generates an oscillating voltage pulseenvelope signal. The generation of this oscillating signal is not related to the input bias voltage of the PCSS, the pulsecircuit components, or the electrode structure of the PCSS, rather it is related to the output characteristic of the PCSS.This physical phenomenon can be explained using the current surge model in photoconducting antenna. Preparingohmic contact electrode on the silicon carbide material forms the PCSS, which generates a large number ofphotogenerated carriers when ultra-fast laser pulses irradiate the surface of the material and Simultaneously applies abias voltage signal between the electrode. At this time inside the PCSS the electric field causes the transient current,radiating electromagnetic wave to the metal coil to generate oscillating signal.展开更多
In order to explain the oscillation heat transfer dynamics of closed loop oscillation heat pipe (CLOHP) with two liquid slugs,analysis on the forces and heat transfer process of the partial gas-liquid phase system inv...In order to explain the oscillation heat transfer dynamics of closed loop oscillation heat pipe (CLOHP) with two liquid slugs,analysis on the forces and heat transfer process of the partial gas-liquid phase system involving multiple parameters was carried out,and a new type oscillation heat transfer dynamic model of the CLOHP was set up based on conservation laws of mass,momentum and energy.Application results indicate that its oscillation heat transfer dynamics features depend largely on the filling rate,pipe diameter and difference in temperature.Besides,oscillation intensity and transfer performance can be improved to a large extent by increasing the temperature difference properly and enlarging the pipe diameter within a certain range under a certain filling rate.展开更多
A dual transponder carrier ranging method can be used to measure inter-satellite distance with high precision by combining the reference and the to-and-fro measurements. Based on the differential techniques, the oscil...A dual transponder carrier ranging method can be used to measure inter-satellite distance with high precision by combining the reference and the to-and-fro measurements. Based on the differential techniques, the oscillator phase noise, which is the main error source for microwave ranging systems, can be significantly attenuated. Further, since the range measurements are derived on the same satellite, the dual transponder ranging system does not need a time tagging system to synchronize the two satellites. In view of the lack of oscillator noise analysis on the dual transponder ranging model, a comprehensive analysis of oscillator noise effects on ranging accuracy is provided. First, the dual transponder ranging system is described with emphasis on the detailed analysis of oscillator noise on measurement precision. Then, a high-fidelity numerical simulation approach based on the power spectrum density of an actual ultra-stable oscillator is carried out in both frequency domain and time domain to support the presented theoretical analysis. The simulation results under different conditions are consistent with the proposed concepts, which makes the results reliable. Besides, the results demonstrate that a high level of accuracy can be achieved by using this oscillator noise cancelation-oriented ranging method.展开更多
The slow wave structure(SWS)of higher-order depressed magnetically insulated transmission line oscillator(HDMILO)is analyzed rigorously,and the electromagnetic field distribution is derived.High-frequency analysis res...The slow wave structure(SWS)of higher-order depressed magnetically insulated transmission line oscillator(HDMILO)is analyzed rigorously,and the electromagnetic field distribution is derived.High-frequency analysis results reveal that the degeneracy of two degenerate HEM!1 modes is removed by the slot in swS plate and the two degenerate modes split into two modes which polarize perpendicularly.Adjusting the azi-muthal position of the slots destroys longitudinal oscillation condition of higher-order modes.展开更多
基金supported by Major Projects of Shanxi Province (202101030201001)。
文摘Constructing a photoconductive semiconductor switch (PCSS)-metal coil structure, we discovered anew phenomenon of electromagnetic oscillation in vanadium-compensation semi-insulating (VCSI) PCSS. Here thePCSS responds to laser pulse and high-voltage signal while the metal coil generates an oscillating voltage pulseenvelope signal. The generation of this oscillating signal is not related to the input bias voltage of the PCSS, the pulsecircuit components, or the electrode structure of the PCSS, rather it is related to the output characteristic of the PCSS.This physical phenomenon can be explained using the current surge model in photoconducting antenna. Preparingohmic contact electrode on the silicon carbide material forms the PCSS, which generates a large number ofphotogenerated carriers when ultra-fast laser pulses irradiate the surface of the material and Simultaneously applies abias voltage signal between the electrode. At this time inside the PCSS the electric field causes the transient current,radiating electromagnetic wave to the metal coil to generate oscillating signal.
基金Project(531107040300)supported by the Fundamental Research Funds for the Central Universities in ChinaProject(51176045)supported by the National Natural Science Foundation of China
文摘In order to explain the oscillation heat transfer dynamics of closed loop oscillation heat pipe (CLOHP) with two liquid slugs,analysis on the forces and heat transfer process of the partial gas-liquid phase system involving multiple parameters was carried out,and a new type oscillation heat transfer dynamic model of the CLOHP was set up based on conservation laws of mass,momentum and energy.Application results indicate that its oscillation heat transfer dynamics features depend largely on the filling rate,pipe diameter and difference in temperature.Besides,oscillation intensity and transfer performance can be improved to a large extent by increasing the temperature difference properly and enlarging the pipe diameter within a certain range under a certain filling rate.
基金Project(61106113)supported by the National Natural Science Foundation of China
文摘A dual transponder carrier ranging method can be used to measure inter-satellite distance with high precision by combining the reference and the to-and-fro measurements. Based on the differential techniques, the oscillator phase noise, which is the main error source for microwave ranging systems, can be significantly attenuated. Further, since the range measurements are derived on the same satellite, the dual transponder ranging system does not need a time tagging system to synchronize the two satellites. In view of the lack of oscillator noise analysis on the dual transponder ranging model, a comprehensive analysis of oscillator noise effects on ranging accuracy is provided. First, the dual transponder ranging system is described with emphasis on the detailed analysis of oscillator noise on measurement precision. Then, a high-fidelity numerical simulation approach based on the power spectrum density of an actual ultra-stable oscillator is carried out in both frequency domain and time domain to support the presented theoretical analysis. The simulation results under different conditions are consistent with the proposed concepts, which makes the results reliable. Besides, the results demonstrate that a high level of accuracy can be achieved by using this oscillator noise cancelation-oriented ranging method.
文摘The slow wave structure(SWS)of higher-order depressed magnetically insulated transmission line oscillator(HDMILO)is analyzed rigorously,and the electromagnetic field distribution is derived.High-frequency analysis results reveal that the degeneracy of two degenerate HEM!1 modes is removed by the slot in swS plate and the two degenerate modes split into two modes which polarize perpendicularly.Adjusting the azi-muthal position of the slots destroys longitudinal oscillation condition of higher-order modes.
