The Experts below are selected from a list of 24333 Experts worldwide ranked by ideXlab platform
Edward I Ackerman - One of the best experts on this subject based on the ideXlab platform.
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gain noise figure and bandwidth limited dynamic range of a low biased External Modulation link
International Topical Meeting on Microwave Photonics, 2007Co-Authors: H V Roussell, Charles H. Cox, Edward I Ackerman, M D Regan, J L Prince, J X Chen, W K Burns, G E Betts, J C CampbellAbstract:We present a broad-bandwidth (1 -12 GHz) low-biased External Modulation fiber-optic link without preamplifiers that has a gain of 6 dB-14 dB and a noise figure of < 7.S dB everywhere in this broad bandwidth, with a record low noise figure of only 3.4 dB at 2 GHz. The third-order distortion-limited spurious-free dynamic range (SFDK) of this link within any suboctavc portion of the 1-12 GHz range of operating frequencies is approximately 120 dBHz2/3 in a 1-Hz instantaneous receiver bandwidth. We describe the high-performance components in this link and discuss the extent to which their performance varies with frequency, and show which of these components' frequency-dependent parameters affect which of the three figures of merit (gain, noise figure, and SFDR).
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effect of pilot tone based modulator bias control on External Modulation link performance
International Topical Meeting on Microwave Photonics, 2000Co-Authors: Edward I AckermanAbstract:The dynamic range of an External Modulation link in which a pilot tone maintains a Mach-Zehnder modulator at quadrature bias is limited to 64/(/spl pi/ m/sub PT/)/sup 4/, where m/sub PT/ is the Modulation depth of the pilot tone.
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broad band External Modulation fiber optic links for antenna remoting applications
IEEE Transactions on Microwave Theory and Techniques, 1997Co-Authors: Edward I Ackerman, A S DaryoushAbstract:We present a 6-12 GHz External Modulation fiber-optic link with a spurious-free dynamic range (SFDR) of 65.5 dB MHz. This result validates an analytical model for External Modulation link performance which we have updated from a previously published model to account for the use of a traveling-wave External modulator. Using the revised model, we compare the expected performance of two different link architectures.
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Balanced receiver External Modulation fiber-optic link architecture with reduced noise figure
1993 IEEE MTT-S International Microwave Symposium Digest, 1993Co-Authors: Edward I Ackerman, S. Wanuga, J. Macdonald, J L PrinceAbstract:The authors describe a fiber-optic link architecture which minimizes noise figure by combining the two complementary outputs of a Y-fed coupler electrooptic modulator in such a way that the optical noise cancels in a balanced receiver module. The demonstration link exhibits 9.5-dB insertion loss and 13.5-dB noise figure at 900 MHz. >
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Maximum dynamic range operation of a microwave External Modulation fiber-optic link
IEEE Transactions on Microwave Theory and Techniques, 1993Co-Authors: Edward I Ackerman, S. Wanuga, D. Kasemset, Afshin S. Daryoush, Niranjan R. SamantAbstract:We fully analyze the analog performance of an External Modulation fiber-optic link. We express relevant figures of merit-including gain, noise figure, third-order interModulation distortion, AM compression, and dynamic range-in terms of the microwave scattering matrices of the modulator and detector circuits, and we predict the modulator bias condition promoting optimum link performance. Our predictions match the measured gain, noise figure, and dynamic range of an experimental 870-930 MHz External Modulation fiber-optic link. Maximum spurious-free dynamic range-77 dB.MHz/sup 2/3/ (117 db.Hz/sup 2/3/)-occurs when the modulator is biased at its halfwave voltage, where the optical throughput is nearly pinched off. >
C. Peyron - One of the best experts on this subject based on the ideXlab platform.
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Insights into paradoxical (REM) sleep homeostatic regulation in mice using an innovative automated sleep deprivation method.
SLEEP, 2020Co-Authors: Sébastien Arthaud, Paul-antoine Libourel, Pierre-hervé Luppi, C. PeyronAbstract:Identifying the precise neuronal networks activated during paradoxical sleep (PS, also called REM sleep) has been a challenge since its discovery. Similarly, our understanding of the homeostatic mechanisms regulating PS, whether through External Modulation by circadian and ultradian drives or via intrinsic homeostatic regulation, is still limited, largely due to interfering factors rendering the investigation difficult. Indeed, none of the studies published so far were able to manipulate PS without significantly altering slow-wave sleep and/or stress level, thus introducing a potential bias in the analyses. With the aim of achieving a better understanding of PS homeostasis, we developed a new method based on automated scoring of vigilance states-using electroencephalogram and electromyogram features-and which involves closed-loop PS deprivation through the induction of cage floor movements when PS is detected. Vigilance states were analyzed during 6 and 48 h of PS deprivation as well as their following recovery periods. Using this new automated methodology, we were able to deprive mice of PS with high efficiency and specificity, for short or longer periods of time, observing no sign of stress (as evaluated by plasma corticosterone level and sleep latency) and requiring no human intervention or environmental changes. We show here that PS can be homeostatically modulated and regulated while no significant changes are induced on slow-wave sleep and wakefulness, with a PS rebound duration depending on the amount of prior PS deficit. We also show that PS interval duration is not correlated with prior PS episode duration in the context of recovery from PS deprivation.
Sébastien Arthaud - One of the best experts on this subject based on the ideXlab platform.
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Insights into paradoxical (REM) sleep homeostatic regulation in mice using an innovative automated sleep deprivation method.
SLEEP, 2020Co-Authors: Sébastien Arthaud, Paul-antoine Libourel, Pierre-hervé Luppi, C. PeyronAbstract:Identifying the precise neuronal networks activated during paradoxical sleep (PS, also called REM sleep) has been a challenge since its discovery. Similarly, our understanding of the homeostatic mechanisms regulating PS, whether through External Modulation by circadian and ultradian drives or via intrinsic homeostatic regulation, is still limited, largely due to interfering factors rendering the investigation difficult. Indeed, none of the studies published so far were able to manipulate PS without significantly altering slow-wave sleep and/or stress level, thus introducing a potential bias in the analyses. With the aim of achieving a better understanding of PS homeostasis, we developed a new method based on automated scoring of vigilance states-using electroencephalogram and electromyogram features-and which involves closed-loop PS deprivation through the induction of cage floor movements when PS is detected. Vigilance states were analyzed during 6 and 48 h of PS deprivation as well as their following recovery periods. Using this new automated methodology, we were able to deprive mice of PS with high efficiency and specificity, for short or longer periods of time, observing no sign of stress (as evaluated by plasma corticosterone level and sleep latency) and requiring no human intervention or environmental changes. We show here that PS can be homeostatically modulated and regulated while no significant changes are induced on slow-wave sleep and wakefulness, with a PS rebound duration depending on the amount of prior PS deficit. We also show that PS interval duration is not correlated with prior PS episode duration in the context of recovery from PS deprivation.
Niranjan R. Samant - One of the best experts on this subject based on the ideXlab platform.
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Maximum dynamic range operation of a microwave External Modulation fiber-optic link
IEEE Transactions on Microwave Theory and Techniques, 1993Co-Authors: Edward I Ackerman, S. Wanuga, D. Kasemset, Afshin S. Daryoush, Niranjan R. SamantAbstract:We fully analyze the analog performance of an External Modulation fiber-optic link. We express relevant figures of merit-including gain, noise figure, third-order interModulation distortion, AM compression, and dynamic range-in terms of the microwave scattering matrices of the modulator and detector circuits, and we predict the modulator bias condition promoting optimum link performance. Our predictions match the measured gain, noise figure, and dynamic range of an experimental 870-930 MHz External Modulation fiber-optic link. Maximum spurious-free dynamic range-77 dB.MHz/sup 2/3/ (117 db.Hz/sup 2/3/)-occurs when the modulator is biased at its halfwave voltage, where the optical throughput is nearly pinched off. >
A S Daryoush - One of the best experts on this subject based on the ideXlab platform.
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broad band External Modulation fiber optic links for antenna remoting applications
IEEE Transactions on Microwave Theory and Techniques, 1997Co-Authors: Edward I Ackerman, A S DaryoushAbstract:We present a 6-12 GHz External Modulation fiber-optic link with a spurious-free dynamic range (SFDR) of 65.5 dB MHz. This result validates an analytical model for External Modulation link performance which we have updated from a previously published model to account for the use of a traveling-wave External modulator. Using the revised model, we compare the expected performance of two different link architectures.
