The Experts below are selected from a list of 135 Experts worldwide ranked by ideXlab platform
Dimitrios Peroulis - One of the best experts on this subject based on the ideXlab platform.
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a quasi absorptive microwave resonant plasma switch for high power applications
IEEE Transactions on Microwave Theory and Techniques, 2018Co-Authors: Abbas Semnani, Sergey Macheret, Dimitrios PeroulisAbstract:In this paper, a new plasma-based high-power microwave single-pole single-throw (SPST) switch is introduced and experimentally investigated. This switch is composed of a two-pole evanescent-mode cavity structure loaded with two Gas Discharge Tubes over its posts. Since part of the energy required for the Tubes ignition is supplied by the incoming electromagnetic waves, the switching mechanism is quasi absorptive. A prototype SPST switch at the frequency range of 2.8–3.9 GHz is fabricated and successfully examined over the power range of 2–20 W. With less than 1 dB of insertion loss, the ON/OFF isolation varies from 13 to 22 dB, depending on the input power. The measured switching time was on the order of tens of nanoseconds, and the input third-order intercept point that characterizes linearity was +53 dBm. Upon ignition, the microwave-sustained plasma in the switch operates in the $\alpha $ -Discharge regime, ensuring that the switch performance is quite stable, with no degradation after long periods of operation.
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Gas Discharge tube-based variable RF attenuator
2016 IEEE 17th Annual Wireless and Microwave Technology Conference (WAMICON), 2016Co-Authors: Abbas Semnani, Zach Vander Missen, Sergey Macheret, Dimitrios PeroulisAbstract:In this paper, tunable RF attenuation using low temperature plasma technology is investigated theoretically and experimentally. Specifically, Gas Discharge Tubes (GDTs) are employed as plasma cells and their impedance is tuned from a high level (zero current or off-mode) to a low level (DC Discharge current or on-mode). A proof-of-concept prototype with two independently-controlled GDTs in a series-shunt topology results in a continuously variable attenuator with maximum attenuation of 20±1 dB in the 0.5–1.2 GHz range. The proposed GDT-based approach may be employed as an RF attenuation technology particularly in emerging applications where conventional techniques cannot be used due to high temperature and/or power.
L.v. Mikhaylovskaya - One of the best experts on this subject based on the ideXlab platform.
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Influence of volume recombination on characteristics of positive column in narrow Gas Discharge Tubes
International Conference on Lasers Applications and Technologies 2007: Advanced Lasers and Systems, 2007Co-Authors: L.v. Mikhaylovskaya, A. S. MykhaylovskaAbstract:The theoretical analysis of the influence of a volume electron-ionic recombination on energy and spatial characteristics of the glow Discharge plasma of the positive column in Gases is developed taking into account the equation for a longitudinal electric field and Ohm's low for a full electrical current. It is shown, that under certain conditions, even in the diffusion mode of glow Discharge, this influence reduces to essential modifications of the internal Discharge parameters (electron temperature, electron concentration at the tube axis and longitudinal electric field). Dependences of the internal Gas Discharge plasma parameters on the external ones, such as Gas pressure, the Discharge current, the radius of working capillary are considered for the narrow Gas Discharge Tubes.
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Influence of Discharge Parameters on Radial Distributions of Charge Particles in Positive Column in Narrow Gas Discharge Tubes
2006 International Workshop on Laser and Fiber-Optical Networks Modeling, 2006Co-Authors: L.v. MikhaylovskayaAbstract:The calculations of the radial distributions of charge particles in positive column in narrow Gas Discharge Tubes are presented. At that the balance equation and Poisson's equation have been solved without condition of the quasineutrality of plasma. The calculations shows that in narrow Gas Discharge Tubes the concentration of the not compensated space positive charge at the center may be much greater than concentration of the electrons at the center.
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Influence of Discharge parameters on space charge in narrow Gas Discharge Tubes
Proceedings of LFNM 2002. 4th International Workshop on Laser and Fiber-Optical Networks Modeling (IEEE Cat. No.02EX549), 1Co-Authors: L.v. MikhaylovskayaAbstract:The expression for magnitude of a volume charge on an axis of a positive column of a glow Discharge is obtained depending on parameters of Discharge. The extreme dependence of a uncompensated positive charge at centre of a Gas Discharge tube from a density of electrons on an axis is established. The electronic temperature and Gas pressure determine location of extremely (maxima) point.
Abbas Semnani - One of the best experts on this subject based on the ideXlab platform.
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a quasi absorptive microwave resonant plasma switch for high power applications
IEEE Transactions on Microwave Theory and Techniques, 2018Co-Authors: Abbas Semnani, Sergey Macheret, Dimitrios PeroulisAbstract:In this paper, a new plasma-based high-power microwave single-pole single-throw (SPST) switch is introduced and experimentally investigated. This switch is composed of a two-pole evanescent-mode cavity structure loaded with two Gas Discharge Tubes over its posts. Since part of the energy required for the Tubes ignition is supplied by the incoming electromagnetic waves, the switching mechanism is quasi absorptive. A prototype SPST switch at the frequency range of 2.8–3.9 GHz is fabricated and successfully examined over the power range of 2–20 W. With less than 1 dB of insertion loss, the ON/OFF isolation varies from 13 to 22 dB, depending on the input power. The measured switching time was on the order of tens of nanoseconds, and the input third-order intercept point that characterizes linearity was +53 dBm. Upon ignition, the microwave-sustained plasma in the switch operates in the $\alpha $ -Discharge regime, ensuring that the switch performance is quite stable, with no degradation after long periods of operation.
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Gas Discharge tube-based variable RF attenuator
2016 IEEE 17th Annual Wireless and Microwave Technology Conference (WAMICON), 2016Co-Authors: Abbas Semnani, Zach Vander Missen, Sergey Macheret, Dimitrios PeroulisAbstract:In this paper, tunable RF attenuation using low temperature plasma technology is investigated theoretically and experimentally. Specifically, Gas Discharge Tubes (GDTs) are employed as plasma cells and their impedance is tuned from a high level (zero current or off-mode) to a low level (DC Discharge current or on-mode). A proof-of-concept prototype with two independently-controlled GDTs in a series-shunt topology results in a continuously variable attenuator with maximum attenuation of 20±1 dB in the 0.5–1.2 GHz range. The proposed GDT-based approach may be employed as an RF attenuation technology particularly in emerging applications where conventional techniques cannot be used due to high temperature and/or power.
Otto Zhou - One of the best experts on this subject based on the ideXlab platform.
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Application of carbon nanoTubes as electrodes in Gas Discharge Tubes
Applied Physics Letters, 2000Co-Authors: Rachel Rosen, William H. Simendinger, Chris Debbault, Hideo Shimoda, Les Fleming, Brian R. Stoner, Otto ZhouAbstract:turn-on fields. Recent experiments have reported turn-on electric fields in the range of 1.5‐3 V/mm. 3‐5 The nanoTubes emitters, especially the SWNTs, are capable of producing stable electron emission with a current density exceeding 4 A/cm 2 ~Ref. 5! which make them attractive cold-cathode materials for microvacuum electronic applications. Assynthesized SWNTs are in the form of either free-standing mat or powder, unsuitable for device applications. We have processed the raw materials to uniform films by a spray method. 6 Adhesion between the substrates and the films is enhanced by introducing either a carbon-dissolving or a carbide-forming metal interlayer. In this letter, we report the effects of carbon nanotube coating on the performance of the Gas Discharge Tubes. The direct current ~dc! breakdown voltages of GDTs fabricated using SWNT-coated electrodes were measured and compared with commercial GDTs. A significant reduction in the breakdown voltage and voltage fluctuation ~over 1000 surges! was observed for the nanotubebased GDTs as compared to typical commercial devices.
Sergey Macheret - One of the best experts on this subject based on the ideXlab platform.
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a quasi absorptive microwave resonant plasma switch for high power applications
IEEE Transactions on Microwave Theory and Techniques, 2018Co-Authors: Abbas Semnani, Sergey Macheret, Dimitrios PeroulisAbstract:In this paper, a new plasma-based high-power microwave single-pole single-throw (SPST) switch is introduced and experimentally investigated. This switch is composed of a two-pole evanescent-mode cavity structure loaded with two Gas Discharge Tubes over its posts. Since part of the energy required for the Tubes ignition is supplied by the incoming electromagnetic waves, the switching mechanism is quasi absorptive. A prototype SPST switch at the frequency range of 2.8–3.9 GHz is fabricated and successfully examined over the power range of 2–20 W. With less than 1 dB of insertion loss, the ON/OFF isolation varies from 13 to 22 dB, depending on the input power. The measured switching time was on the order of tens of nanoseconds, and the input third-order intercept point that characterizes linearity was +53 dBm. Upon ignition, the microwave-sustained plasma in the switch operates in the $\alpha $ -Discharge regime, ensuring that the switch performance is quite stable, with no degradation after long periods of operation.
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Gas Discharge tube-based variable RF attenuator
2016 IEEE 17th Annual Wireless and Microwave Technology Conference (WAMICON), 2016Co-Authors: Abbas Semnani, Zach Vander Missen, Sergey Macheret, Dimitrios PeroulisAbstract:In this paper, tunable RF attenuation using low temperature plasma technology is investigated theoretically and experimentally. Specifically, Gas Discharge Tubes (GDTs) are employed as plasma cells and their impedance is tuned from a high level (zero current or off-mode) to a low level (DC Discharge current or on-mode). A proof-of-concept prototype with two independently-controlled GDTs in a series-shunt topology results in a continuously variable attenuator with maximum attenuation of 20±1 dB in the 0.5–1.2 GHz range. The proposed GDT-based approach may be employed as an RF attenuation technology particularly in emerging applications where conventional techniques cannot be used due to high temperature and/or power.
