Exploring new active materials for low-noise room-temperature microwave amplifiers and other devices

1998 ◽  
Vol 46 (12) ◽  
pp. 2137-2144 ◽  
Author(s):  
A. Blank ◽  
R. Kastner ◽  
H. Levanon
Keyword(s):  
Room Temperature ◽  
Low Noise ◽  
Active Materials ◽  
Microwave Amplifiers

scholarly journals Polymorphic gallium for active resonance tuning in photonic nanostructures: from bulk gallium to two-dimensional (2D) gallenene

Nanophotonics ◽  
2020 ◽  
Vol 9 (14) ◽  
pp. 4233-4252
Author(s):  
Yael Gutiérrez ◽  
Pablo García-Fernández ◽  
Javier Junquera ◽  
April S. Brown ◽  
Fernando Moreno ◽  
...  
Keyword(s):  
Optical Properties ◽  
Room Temperature ◽  
Phase Change Materials ◽  
Two Dimensional ◽  
Active Materials ◽  
Promising Candidate ◽  
Plasmonic Structures ◽  
Resonance Tuning ◽  
The Many ◽  
Optical Behavior

AbstractReconfigurable plasmonics is driving an extensive quest for active materials that can support a controllable modulation of their optical properties for dynamically tunable plasmonic structures. Here, polymorphic gallium (Ga) is demonstrated to be a very promising candidate for adaptive plasmonics and reconfigurable photonics applications. The Ga sp-metal is widely known as a liquid metal at room temperature. In addition to the many other compelling attributes of nanostructured Ga, including minimal oxidation and biocompatibility, its six phases have varying degrees of metallic character, providing a wide gamut of electrical conductivity and optical behavior tunability. Here, the dielectric function of the several Ga phases is introduced and correlated with their respective electronic structures. The key conditions for optimal optical modulation and switching for each Ga phase are evaluated. Additionally, we provide a comparison of Ga with other more common phase-change materials, showing better performance of Ga at optical frequencies. Furthermore, we first report, to the best of our knowledge, the optical properties of liquid Ga in the terahertz (THz) range showing its broad plasmonic tunability from ultraviolet to visible-infrared and down to the THz regime. Finally, we provide both computational and experimental evidence of extension of Ga polymorphism to bidimensional two-dimensional (2D) gallenene, paving the way to new bidimensional reconfigurable plasmonic platforms.

scholarly journals Low-noise correlation measurements based on software-defined-radio receivers and cooled microwave amplifiers

2016 ◽  
Vol 87 (11) ◽  
pp. 114706 ◽  
Author(s):  
Teemu Nieminen ◽  
Pasi Lähteenmäki ◽  
Zhenbing Tan ◽  
Daniel Cox ◽  
Pertti J. Hakonen
Keyword(s):  
Software Defined Radio ◽  
Low Noise ◽  
Noise Correlation ◽  
Radio Receivers ◽  
Microwave Amplifiers

Low-noise room-temperature wideband parametric amplifiers

1971 ◽  
Vol 7 (22) ◽  
pp. 657 ◽  
Author(s):  
J.C. Vokes ◽  
J.R. Dawsey ◽  
H.A. Deadman
Keyword(s):  
Room Temperature ◽  
Low Noise ◽  
Parametric Amplifiers

Framework Structures for Mg Battery Cathodes

2016 ◽  
Vol 879 ◽  
pp. 2150-2152
Author(s):  
Shunsuke Yagi ◽  
Masaaki Fukuda ◽  
Tetsu Ichitsubo ◽  
Eiichiro Matsubara
Keyword(s):  
Prussian Blue ◽  
Room Temperature ◽  
Active Material ◽  
Electrochemical Quartz Crystal Microbalance ◽  
High Energy ◽  
Rechargeable Batteries ◽  
High Energy Density ◽  
Active Materials ◽  
Large Space ◽  
Extraction Behavior

Rechargeable Mg batteries have received intensive attention as affordable rechargeable batteries with high electromotive force, high energy density, and high safety. Mg possesses two valence electrons and has the lowest standard electrode potential (ca. -2.36 V vs. SHE) among the air-stable metals. There is another advantage that Mg metal can be used as an active material because Mg metal hardly forms dendrites. However, the slow diffusion of Mg ions in solid crystals prevents the realization of active materials for Mg rechargeable batteries at room temperature. Although some complex oxides have been reported to work as active materials at higher temperatures, Chevrel compounds are still the gold standards, which work at room temperature. However, the working voltage of the Mg battery using a Chevrel compound for the cathode is only ca. 1.2 V, which is far below that of Li-ion batteries (3-5 V). Nevertheless, Chevrel compounds have the significant advantage that a relatively large space exists in the crystal structure, which allows for fast Mg ion diffusion. In the present study, we investigated some materials with framework structures as cathodes for Mg batteries, which can alleviate the electrostatic constraint between Mg ions and cathode constituents. Specifically, we investigated the redox behavior of the thin films of Prussian blue and Prussian blue analogues in electrolytes containing an Mg salt using electrochemical quartz crystal microbalance and X-ray absorption spectroscopy. In addition, we discuss the electrochemical insertion/extraction behavior of Mg ions and their solvation structures.

Magnetoelectric Sensors With Directly Integrated Charge Sensitive Readout Circuit—Improved Field Sensitivity and Signal-to-Noise Ratio

2011 ◽  
Vol 11 (10) ◽  
pp. 2260-2265 ◽  
Author(s):  
Zhao Fang ◽  
Ninad Mokhariwale ◽  
Feng Li ◽  
Suman Datta ◽  
Q. M. Zhang
Keyword(s):  
Room Temperature ◽  
Signal To Noise Ratio ◽  
Low Noise ◽  
Magnetic Sensors ◽  
Readout Circuit ◽  
Signal To Noise ◽  
Low Frequencies ◽  
Field Sensitivity ◽  
Piezoelectric Layers ◽  
Noise Ratio

The large magnetoelectric (ME) coupling in the ME laminates makes them attractive for ultrasensitive room temperature magnetic sensors. Here ,we investigate the field sensitivity and signal-to-noise ratio (SNR) of ME laminates, consisting of magnetostrictive and piezoelectric layers (Metglas and piezopolymer PVDF were used as the model system), which are directly integrated with a low noise readout circuit. Both the theoretical analysis and experimental results show that increasing the number of piezoelectric layers can improve the SNR, especially at low frequencies. We also introduce a figure of merit to measure the overall influence of the piezolayer properties on the SNR and show that the newly developed piezoelectric single crystals of PMN-PT and PZN-PT have the promise to achieve a very high SNR and consequently ultra-high sensitivity room temperature magnetic sensors. The results show that the ME coefficients used in early ME composites development works may not be relevant to the SNR. The results also show that enhancing the magnetostrictive coefficient, for example, by employing the flux concentration effect, can lead to enhanced SNR.

New Perspectives in Low Noise Preamplifier Design for Room Temperature Detector Applications

1993 ◽  
Vol 302 ◽  
Author(s):  
P.F. Manfredi
Keyword(s):  
Room Temperature ◽  
Silicon Detector ◽  
Low Noise ◽  
Discrete Elements ◽  
Active Devices ◽  
Temperature Detector ◽  
Low Noise Preamplifier

ABSTRACTAfter reviewing the noise limits in room temperature preamplifiers based on discrete elements, the paper discusses some results obtained with monolithic circuits and the perspectives opened-up by active devices directly integrated on the chip of a silicon detector.

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